Psilocybin Species & Mycology
trace–19.9 mg psilocybin per gram of dried P. cubensis across published analyses
A 2025 review compiling P. cubensis measurements across five decades found psilocybin anywhere from trace amounts to 19.9 mg/g — roughly zero to 2% by dry weight — with psilocin varying so widely that some samples contain none at all.
Kurzbaum et al., Journal of Fungi, 2025
~165
species in the Psilocybe genus (Bradshaw et al., PNAS, 2024)
4 enzymes
characterised in the psilocybin biosynthetic pathway (Fricke et al., 2017)
5 alkaloids
quantified in P. cubensis: psilocybin, psilocin, baeocystin, norbaeocystin, aeruginascin
Kurzbaum et al., Journal of Fungi, 2025
View as image ↗Psilocybe cubensis is a Schedule I controlled substance in the United States and illegal in most jurisdictions worldwide. This article is scientific and educational content covering the species' taxonomy, natural history, chemistry, and the published research literature. It contains no cultivation instructions, acquisition guidance, or dosing information, and it is not medical advice.
Psilocybe cubensis is a psilocybin-containing fungus native to tropical and subtropical regions on every inhabited continent. It is the most widely cultivated psychedelic mushroom in the world, and the mushroom most people mean when they refer to "magic mushrooms" in everyday conversation.
It is also, in a way that is easy to miss, remarkably thinly measured. Its biosynthetic pathway (the sequence of enzyme-driven reactions that converts the amino acid tryptophan into psilocybin) was characterised in 2017. Its place within the Psilocybe genus was mapped by a landmark phylogenomics study in 2024. But the single question people ask most often about it — how much psilocybin is actually in it — has no settled answer, and the 2025 review that surveys the literature says so plainly: nearly four decades of regulatory restriction have left the species with a research base far smaller than its cultural footprint.
What follows is what the published science says, and where it stops.
Key Takeaways
- Psilocybe cubensis is a psilocybin-containing fungus native to tropical and subtropical regions. It is Schedule I in the US and illegal in most jurisdictions.
- A 2024 PNAS phylogenomics study placed P. cubensis within a genus of roughly 165 Psilocybe species and dated the genus stem lineage to about 67 million years ago.
- That study also concluded psilocybin biosynthesis first arose within Psilocybe, then moved outward to other mushroom genera through four to five possible horizontal gene transfers between 40 and 9 million years ago.
- Psilocybin is built from tryptophan by four enzymes (Fricke et al. 2017). The order is PsiD, PsiH, PsiK, PsiM — the methyltransferase PsiM performs the terminal step, not the hydroxylase.
- Five alkaloids have been quantified in P. cubensis: psilocybin, psilocin, baeocystin, norbaeocystin, and aeruginascin. Caps carry roughly twice the alkaloid content of stipes, though the authors report that difference as not statistically significant.
- Compiled published analyses put psilocybin between trace amounts and 19.9 mg/g of dried mushroom. There is no defensible "typical" figure — the datasets separate by provenance rather than converging.
- The 1982 flush study is widely misreported. Psilocybin showed no upward or downward trend across successive harvests, varying four-fold with no direction; psilocin was near zero in the first flush and peaked by the fourth.
- No peer-reviewed study has ever quantified Penis Envy or Golden Teacher. The only published LC-MS/MS strain comparison tested five other varieties, and found a 1.5-fold spread among them.
What Psilocybe cubensis Is: Taxonomy and Classification
Psilocybe cubensis is a species of fungus in the order Agaricales, class Agaricomycetes. It was first formally described by Franklin Sumner Earle in 1906 as Stropharia cubensis, and transferred to Psilocybe by Rolf Singer in 1948. The epithet "cubensis" refers to Cuba, where the type specimen was collected.
Family placement is less settled than most popular accounts suggest. Contemporary treatments generally place Psilocybe in Hymenogastraceae, but the older Strophariaceae designation persists in the current literature — a 2021 analytical paper on this very species writes "the genus Psilocybe (Fungi, Strophariaceae)" without comment.[4] This is a live taxonomic question rather than a resolved one, and sources that state a single family as settled fact are overstating the position.
The genus itself was the subject of a landmark 2024 phylogenomics study by Bradshaw and colleagues, published in the Proceedings of the National Academy of Sciences.[7] Working from shotgun sequencing of fungarium specimens, they obtained 71 metagenomes — 23 of them from type specimens — and built a fully supported phylogeny from 2,983 single-copy gene families. Their molecular clock places the stem lineage of Psilocybe at roughly 67 million years ago, diversifying around 56 million years ago.
Common names for Psilocybe cubensis include "magic mushrooms," "shrooms," "golden caps" (for the characteristic golden-caramel colour of mature caps), "cubes," and "gold tops." In Spanish-speaking regions it is sometimes called "hongos," and the Nahuatl term "teonanácatl" is sometimes applied, though that term refers to sacred mushrooms generally rather than to this species.
P. cubensis is distinguished from other Psilocybe species by its coprophilic lifestyle (growing on large herbivore dung rather than on wood or soil), its relatively large fruiting bodies, and its wide distribution across tropical and subtropical zones. It is not the most potent Psilocybe species: in the largest survey of tryptamine content across the genus, P. cyanescens reached psilocybin concentrations several times higher than any P. cubensis sample measured.[6] What P. cubensis has instead is accessibility.
The Bradshaw study also produced the most significant recent finding in psilocybin mycology, and it is routinely reported backwards. The paper concludes that psilocybin biosynthesis first arose in Psilocybe, and then moved outward — four to five possible horizontal transfers into other mushroom genera between roughly 40 and 9 million years ago. Separately, and this is the part usually conflated with the first, they found two distinct gene orders within the biosynthetic cluster corresponding to a deep split in the genus, which they describe as possibly a signature of two independent acquisitions within Psilocybe. Neither finding says psilocybin evolved convergently from scratch in unrelated lineages. For a deeper look, see Horizontal Gene Transfer: How Psilocybin Genes Jump Between Species.[7]
Where Psilocybe cubensis Grows: A Coprophilic Species in Tropical Dung
Psilocybe cubensis is what mycologists call a coprophilic species: it grows primarily on and in the dung of large herbivores, particularly cattle and horses. This association with grazing animals is the key to the species' wide modern distribution.
In its natural environment, P. cubensis fruit bodies emerge after rain events in tropical and subtropical pastures and grasslands. Fruiting requires warmth and high relative humidity, which is why the species is confined to the tropics and subtropics and why its appearance in the wild tracks rainfall rather than the calendar.[9] In seasonally wet regions within its range, it fruits in cycles tied to the rainy season.
Natural distribution covers a wide band. The species occurs throughout Central and South America, the Gulf Coast region of the United States, Mexico, Cuba, and the Caribbean. It is also found in Southeast Asia, South Asia, parts of Africa, and Australia. Essentially any warm, humid region with a history of cattle grazing falls within its potential range. The movement of cattle during the colonial era is generally thought to have extended the species' range well beyond its original distribution, though this is a historical inference rather than a documented result.
From Mazatec Ceremony to Modern Research: The History
Indigenous Mesoamerican use of psilocybin-containing mushrooms predates European contact. The Aztec term "teonanácatl," which Nichols renders as "god's flesh," appears in colonial-era Spanish sources; Spanish missionaries in the 1500s attempted to destroy the records of these practices, and a 16th-century Franciscan friar's surviving account is what set 20th-century ethnopharmacologists on a decades-long search for the mushroom's identity.[3] Which species were involved in pre-Columbian use is still debated, and teonanácatl was almost certainly not a single species.
That search ended, as Nichols tells it, in a 1957 photo-essay in a popular magazine — R. Gordon Wasson's "Seeking the Magic Mushroom" in Life — describing a Mazatec ceremony in Oaxaca led by the curandera María Sabina.[3] It is worth being precise about what that moment did and did not involve: the mushrooms used in the ceremonies Wasson attended were local Oaxacan species, and the material Hofmann subsequently worked from was Psilocybe mexicana, not P. cubensis. What the episode opened was Western scientific access to psilocybin mushrooms in general. P. cubensis became the research and cultivation workhorse afterwards, and for reasons of ecology rather than ceremony.
Albert Hofmann, who had first synthesised LSD in 1938, obtained specimens and by 1958 had identified and chemically synthesised the active principles, psilocybin and psilocin. Nichols frames this as the turning point: a naturally occurring psychedelic now had a known structure and a synthetic route, which is what made systematic pharmacology possible.[3]
The 1960s brought both research and backlash. Timothy Leary and colleagues at Harvard ran early psilocybin experiments using synthetic material rather than mushrooms; the Concord Prison Experiment and the Marsh Chapel Experiment date from this period. The cultural and political reaction against psychedelics led to psilocybin's placement in Schedule I under the US Controlled Substances Act of 1970, which largely ended clinical research for two decades.
The revival began in the 1990s and accelerated sharply after 2010. Nichols, writing in 2020, describes FDA-approved studies over the preceding ten to fifteen years indicating potential medical value for psilocybin-assisted psychotherapy in depression, anxiety and certain addictions, while noting that this rests on the assumption that early results survive larger trials.[3] That research uses synthetic psilocybin. The mushroom itself is now studied mainly in mycological and analytical chemistry contexts.
The Chemistry: A Four-Enzyme Pathway and Five Alkaloids
Psilocybin is the primary psychoactive compound in P. cubensis. Chemically it is 4-phosphoryloxy-N,N-dimethyltryptamine, a tryptamine carrying a phosphate group at the 4-position. It is a prodrug: inactive as stored, it is dephosphorylated after ingestion to psilocin (4-hydroxy-N,N-dimethyltryptamine), which crosses the blood-brain barrier and binds serotonin receptors.
Psilocin acts primarily at the 5-HT2A serotonin receptor. That binding is the molecular event from which the downstream neurological effects follow. For a detailed treatment, see How 5-HT2A Agonism Creates the Psychedelic Experience.
The pathway by which the mushroom manufactures psilocybin was characterised in 2017 by Fricke, Blei, and Hoffmeister at the Hans Knöll Institute in Jena.[2] They characterised four enzymes: PsiD, representing a new class of fungal L-tryptophan decarboxylases; PsiH, a monooxygenase; PsiK, which catalyses the phosphotransfer step; and the methyltransferase PsiM, which catalyses iterative N-methyl transfer as the terminal biosynthetic step.
Four Enzymes, In Order
How the Mushroom Builds Psilocybin From an Ordinary Amino Acid
The order matters and is frequently reported wrongly. PsiH acts second, not last; the terminal step belongs to the methyltransferase PsiM. The 2017 paper that characterised these enzymes ran its reaction along the dashed entry below, skipping PsiH.
Starting material
L-tryptophan
A common amino acid. Nothing about it is exotic — it is in the mushroom’s food supply and in yours.
Removes the carboxyl group → tryptamine
Hydroxylates the 4-position → 4-hydroxytryptamine
The step Fricke’s reconstituted reaction skipped, by starting one intermediate downstream.
Laboratory shortcut
Fricke 2017 fed 4-hydroxy-L-tryptophan to a combined PsiD/PsiK/PsiM reaction, entering the chain here and producing psilocybin without PsiH. This is why the paper is titled an enzymatic synthesis rather than a complete reconstitution from tryptophan.
Adds the phosphate group → norbaeocystin
Iterative N-methyl transfer, twice over → baeocystin, then psilocybin
Terminal biosynthetic step
Final product
Psilocybin — 4-phosphoryloxy-N,N-dimethyltryptamine
Inactive as stored. The phosphate group added at step 3 is removed again after ingestion to give psilocin, which is the molecule that reaches the brain.
The four genes travel together as a cluster rather than scattered across the genome. Comparative genomics across Psilocybe has since found two distinct gene orders within that cluster, tracking a deep split in the genus — the same four enzymes, arranged two different ways.
Intermediate names follow the standard sequence for this pathway. This figure describes how a fungus makes a molecule; it contains no dose, potency or yield figure, and nothing here is guidance of any kind.
Sources: Fricke, Blei & Hoffmeister 2017 (Angew Chem Int Ed 56(40):12352–12355) for the four enzymes, their roles, the terminal step and the step-economic route; Bradshaw et al. 2024 (PNAS 121(3):e2311245121) for the two cluster gene orders.
Fricke's team also demonstrated the chemistry outside the mushroom, and the way they did it is worth stating accurately. They ran a combined PsiD/PsiK/PsiM reaction starting from 4-hydroxy-L-tryptophan — a step-economic route that enters the pathway one intermediate downstream and bypasses PsiH altogether. That is an enzymatic synthesis of psilocybin, and a genuinely important one for biotechnological production. It is not a complete end-to-end reconstitution from tryptophan, and describing it as a "total synthesis" overstates what was demonstrated.[2]
The blue-green bruising reaction that appears when P. cubensis tissue is damaged is connected to this same chemistry. Psilocybin is dephosphorylated to psilocin and then oxidised, and the oxidation products couple into blue oligomers — which is why bruising is treated as an informal indicator of psilocybin-containing species, and why it is not a reliable identification method on its own. The direction of the reaction is also frequently misread: blue marks psilocybin that has already been consumed by the reaction, not psilocybin that is present. For the chemistry and its limits, see Is Blue Bruising a Reliable Indicator of Psilocybin?.
P. cubensis contains three further tryptamine alkaloids beyond psilocybin and psilocin. Gotvaldová and colleagues quantified all five in their 2021 study of the species:[4]
- Psilocybin — the most abundant of the five in fruiting bodies
- Psilocin — the active form after dephosphorylation; measured at 0.47 wt.% in mycelium, which contained no other tryptamine
- Baeocystin — a partly methylated intermediate, present in smaller amounts
- Norbaeocystin — the unmethylated precursor produced by PsiK; trace amounts, little studied pharmacologically
- Aeruginascin — a trimethylated quaternary ammonium analogue, variable across samples
That study also produced two findings that get quoted without their caveats. Stipes contained roughly half the tryptamine content of caps — 0.52 wt.% against 1.03 wt.% — but the authors explicitly report that difference as not statistically significant, because alkaloid content varies so much between individual fruiting bodies that it swallows a two-fold anatomical difference. And no tryptamines at all were detected in basidiospores.
Gotvaldová et al. (2021) · Drug Testing and Analysis
- Population
- Freshly cultivated Psilocybe cubensis fruiting bodies, separated into caps, stipes and basidiospores, plus mycelium
- Intervention
- UHPLC-MS quantification of psilocybin, psilocin, baeocystin, norbaeocystin and aeruginascin across tissue types and storage conditions
- Finding
- Stipes held about half the tryptamine content of caps (0.52 vs 1.03 wt.%), but the authors report the difference as not statistically significant given between-mushroom variability. No tryptamines were detected in basidiospores; mycelium contained only psilocin, at 0.47 wt.%. On storage, the greatest degradation occurred in fresh mushrooms held at −80 °C; the least occurred in dried biomass kept dark at room temperature.
mixed The cap-versus-stipe figures circulate as a settled two-to-one ratio. The paper that produced them declines to call the difference significant. The storage result is the more useful finding and the more counter-intuitive one — freezing fresh material was the worst option tested.
Gotvaldová K, et al. Drug Test Anal. 2021;13(2):439-446. PMID 33119971
The storage finding deserves emphasis because it runs against intuition. Freezing fresh fruiting bodies at −80 °C — the treatment most people would assume is the most protective — produced the highest degradation of any condition tested. Drying the material and keeping it dark at room temperature preserved it best. Whatever the mechanism, it means that a potency figure attaches to a particular sample handled a particular way, not to a strain or a species.
A separate 2022 genomic survey by Dörner and colleagues examined the genomes of five Psilocybe species (P. azurescens, P. cubensis, P. cyanescens, P. mexicana, and P. serbica) and found a far greater and largely unexplored metabolic capacity than chemical analysis alone had revealed.[5] They identified P. cyanescens and P. mexicana as aeruginascin producers, and detected lumichrome and verpacamide A as Psilocybe metabolites. Their framing is that this uncharted secondary metabolome may eventually explain phenomena attributed to some magic mushrooms — such as reported paralytic effects — that psilocybin alone does not account for. What the survey did not do is establish which genetic variants drive alkaloid ratios between P. cubensis strains; that remains open.
Psilocybin Content: What the Analytical Chemistry Actually Shows
This is the question people arrive with, and it is the one the literature answers worst.
There Is No Single Potency Figure
Published Psilocybin Content, By Where the Mushroom Came From
Each bar is the reported range from a different body of published measurement, on one shared axis. They do not converge on a value. They separate by provenance — which is the actual finding, and the reason a single “typical” number for this species cannot be sourced.
Five decades of measurements pooled in one 2025 review table — wild, cultivated and herbarium material together. (~0–1.99% by dry weight)
Dried fruiting bodies collected in 1970, 1974 and 1978 and held at the University of Washington herbarium. The highest figures in the literature come from this material. (1.05–1.99% by dry weight)
Five strains grown under controlled conditions and quantified by LC-MS/MS in a single laboratory — the tightest dataset available, and the only head-to-head strain comparison. (0.81–1.30% by dry weight)
Fruiting bodies raised on a cow-dung and rice-grain substrate under controlled humidity and temperature. (0.04–0.63% by dry weight)
Wild-collected fruiting bodies, most backed by fungarium specimens or DNA sequencing — the most rigorously identified material, and among the least potent measured. (0.07–0.35% by dry weight)
The most carefully identified material — wild collections backed by fungarium vouchers and DNA sequencing — is also among the least potent measured, while decades-old dried herbarium specimens sit at the top of the range. Any explanation of that pattern has to account for cultivation conditions, harvest timing, drying and storage all at once. No published study has separated them.
Bars are reported ranges, not distributions: they show the span of published values, not how samples are distributed within it. Sample counts differ by orders of magnitude between bands, and none of these datasets was designed to be compared with the others. Psilocin is excluded here because it varies independently — some samples contain none at all. Nothing on this chart is a dose, a recommendation, or a basis for estimating the content of any particular mushroom.
Sources: Kurzbaum et al. 2025 (J Fungi 11(2):99, Table 1) for the compiled span, the herbarium vouchers, the dung-and-rice cultivation figures and the mg/g tabulation of Goff et al. 2024 (Anal Chim Acta 1288:342161); Gotvaldová et al. 2022 (Int J Mol Sci 23(22):14068) for the documented wild collections.
The compiled picture comes from Kurzbaum and colleagues' 2025 review, which tabulates published P. cubensis quantifications across five decades of laboratory-grown and wild-collected material.[9] Their summary of that table: psilocybin levels range from trace amounts to 19.9 mg/g, while psilocin concentrations vary widely, with some samples showing no detectable levels. That is a range spanning essentially zero to about 2% by dry weight, and it is the honest answer to "how much psilocybin is in P. cubensis."
Two datasets inside that span are worth separating out, because they pull in opposite directions.
Gotvaldová and colleagues' 2022 survey is the most rigorously identified material available: 226 fruiting bodies from 82 collections across seven genera, most documented by fungarium specimens or ITS rDNA/LSU/EF1-α sequencing.[6] The P. cubensis component of that survey was small — nine fruiting bodies from four collections — and measured psilocybin at 0.651–3.509 mg/g, near the bottom of the published range. The authors' own conclusion is blunt: tryptamine concentrations in mushrooms are extremely variable, which they frame as a genuine overdose risk.
Gotvaldová et al. (2022) · International Journal of Molecular Sciences
- Population
- 226 fruiting bodies from 82 individual collections across seven mushroom genera; the P. cubensis subset was nine fruiting bodies from four collections
- Intervention
- UHPLC-MS/MS quantification of psilocybin, psilocin, baeocystin, norbaeocystin and aeruginascin, with most collections documented by fungarium specimens and/or DNA sequencing
- Finding
- For P. cubensis specifically: psilocybin 0.651–3.509 mg/g and psilocin 0.208–5.344 mg/g. Across the genus the highest concentrations were in Psilocybe species, but no tryptamines at all were detected in P. fuscofulva or P. fimetaria. The authors characterise the variability as posing an apparent risk of overdose.
mixed Exceptional identification rigour — DNA-sequenced and voucher-backed — but the P. cubensis sample is nine mushrooms. The species most people ask about is one of the thinnest slices of the survey.
Gotvaldová K, et al. Int J Mol Sci. 2022;23(22):14068. PMID 36430546
Pulling the other way are the herbarium vouchers in Kurzbaum's table: University of Washington specimens collected in 1970, 1974 and 1978, measured at 10.5–15.44, 16.33–17.3 and 18.3–19.9 mg/g respectively.[9] These decades-old dried specimens supply the top of the entire published range.
Bigwood and Beug published the first systematic analysis of within-culture variation in 1982, and it is one of the most consistently misreported papers in this literature.[1] The received version — "the first flush is the strongest, and potency declines with each harvest" — is not what the paper found. What it found was stranger.
Bigwood & Beug (1982) · Journal of Ethnopharmacology
- Population
- Psilocybe cubensis grown in controlled culture, sampled across successive flushes (harvests) from the same culture, plus samples obtained from outside sources
- Intervention
- Quantification of psilocybin and psilocin levels in mature sporocarps across repeated flushes
- Finding
- Psilocybin showed no upward or downward trend as fruiting progressed, but varied over a factor of four. Psilocin was generally zero in the first — and sometimes the second — flush from a given culture, reaching its maximum only by the fourth. Psilocybin was nearly always at least twice the psilocin level. Samples from outside sources varied by over a factor of ten between collections.
narrow-scope Small, old, and single-laboratory — but it is still the only systematic study of flush-to-flush variation, and it directly contradicts the cultivation lore usually attributed to it. Psilocin trends upward across flushes; psilocybin trends in no direction at all.
Bigwood J, Beug MW. J Ethnopharmacol. 1982;5(3):287-91. PMID 7201054
Two consequences follow. First, genetically identical mycelium in identical substrate produces a four-fold psilocybin swing with no direction to it — so any comparison between two individual mushrooms, of any strains, is being made against a noise floor larger than most claimed effects. Second, the psilocin result means the ratio of the two main alkaloids shifts across harvests, not just the total. The 1982 paper remains the only systematic examination of the question, which is itself a finding about the state of the field.
For a fuller breakdown of the analytical data, see Psilocybin Content in P. cubensis: How Much Is Actually There?.
Why Psilocybe cubensis Is the Most Cultivated Psilocybin Mushroom
P. cubensis is not the most potent psilocybin mushroom. Its dominance is ecological and historical.
First, its ecology is unusually forgiving. Where P. azurescens requires specific wood substrates and cooler coastal conditions, and P. semilanceata occupies narrow grassland niches, P. cubensis colonises dung — an abundant, nitrogen-rich, easily replicated substrate — and tolerates a broad band of warm, humid conditions.
Second, as a coprophile it is an efficient decomposer of high-nitrogen material, which makes it a fast colonizer and gives visible results quickly compared with wood-decomposing fungi.
Third, its global tropical and subtropical distribution meant Western scientists and travellers in the 1960s and 1970s encountered it repeatedly across the Gulf Coast, Mexico, and Southeast Asia. Ubiquity in accessible environments drove its dominance in both research and cultivation.
Fourth, decades of community cultivation have accumulated a large body of practical knowledge and material. Kurzbaum and colleagues' 2025 review, which describes dozens of P. cubensis strains, is candid about what this means for the evidence base: the strain descriptions available are "predominantly sourced from non-academic, community-based reports," because legislative restrictions have limited formal academic research on the species.[9]
Named Strain Varieties: What "Strain" Means Scientifically
Dozens of named P. cubensis varieties circulate in cultivation communities. Golden Teacher, B+, Amazonian, and Penis Envy carry well-established meanings there. Their scientific status is a different matter.
A biological strain or variety, in mycological terms, is a population with consistent, heritable traits differing from the type. By that definition most named P. cubensis "strains" are better described as cultivar selections — phenotypic variants chosen by hobbyists for appearance, yield, or growth behaviour, and not formally characterised as taxonomic varieties in peer-reviewed literature.
Kurzbaum 2025 is the most current academic treatment.[9] It names and describes the major varieties, summarises what is known about their genetics and compound profiles, and is explicit that the descriptions come from community reporting rather than controlled study. It reports no strain-specific potency measurement for Golden Teacher or Penis Envy.
The only published head-to-head comparison of named strains is Goff and colleagues' 2024 LC-MS/MS study — and the strains it tested are not the famous ones.[8]
Which Strains Have Actually Been Measured
The Most-Discussed Strains Are Not the Most-Measured Ones
The three varieties this article compares sit on the left. The five varieties that a published mass-spectrometry study actually quantified sit below. The two sets overlap in exactly one place.
Named and described in the 2025 review, but absent from the only published LC-MS/MS strain comparison.
The single point of overlap. Measured at 1.134% w/w total psilocybin + psilocin, third of the five strains tested.
Described as exceptionally potent in the 2025 review, but no published study has ever quantified it.
The five strains Goff 2024 measured
1.5× separates the most and least potent strain in the only published comparison — 0.879% to 1.36% w/w. Community accounts routinely describe 2–3× differences between named strains. No published measurement spans that range.
Reported figures are the average of three whole, intact mushrooms analysed individually per strain. The same study found content differences between mushrooms of the same strain, and reported improved precision only when multiple mushrooms were homogenised together before extraction — so within-strain variation is real and these averages understate it. Absence of a published measurement is not evidence that a strain is ordinary; it means no one has reported measuring it. Nothing here is a recommendation, and unregulated material carries identification and contamination risks no potency figure addresses.
Sources: Goff et al. 2024 (Anal Chim Acta 1288:342161) for all measured strain potencies; Kurzbaum et al. 2025 (J Fungi 11(2):99) for the named-strain descriptions.
Goff et al. (2024) · Analytica Chimica Acta
- Population
- Five strains of dried, intact Psilocybe cubensis: Blue Meanie, Creeper, B-Plus, Texas Yellow and Thai Cubensis. Neither Penis Envy nor Golden Teacher was included.
- Intervention
- LC-MS/MS quantification of psilocybin and psilocin using internal standard calibration with deuterated isotopologues; three whole intact mushrooms analysed individually per strain
- Finding
- Average total psilocybin plus psilocin ran from 1.36% (Creeper) down to 0.879% (Thai Cubensis) by weight — a 1.5-fold spread. A subset was re-analysed at a separate non-affiliated laboratory with comparable results; that laboratory reported improved precision only when multiple mushrooms were homogenised together before extraction.
narrow-scope Strong, cross-validated analytical method, but five strains and three mushrooms each. Two of the co-authoring organisations manufacture the instrumentation and supplied the standards — disclosed by the authors as a competing interest.
Goff R, et al. Anal Chim Acta. 2024;1288:342161. PMID 38220293
Three varieties dominate popular discussion. Here is what is actually measured for each:
| Variety | Peer-reviewed potency measurement | What is documented |
|---|---|---|
| Golden Teacher | None published | Described in Kurzbaum 2025 as renowned for vigorous growth and substantial effects — a community-sourced characterisation, not a measurement |
| B+ | Yes — 1.134% w/w total psilocybin + psilocin (Goff 2024) | Third of the five strains Goff measured; Kurzbaum notes its reputation for resilience and consistent productivity |
| Penis Envy | None published | Morphologically distinct: dense white stem, small irregular cap, typically lacking the annulus present in most cubensis. Kurzbaum notes its reputation for exceptional potency, explicitly sourced to community reports |
Fact Check
'Penis Envy has been proven more potent by mass spectrometry'
The claim
“Laboratory analysis has confirmed that the Penis Envy variety contains significantly more psilocybin than typical P. cubensis strains, validating what cultivators have long reported.”
A widely repeated misattribution of Goff et al.'s 2024 LC-MS/MS study, which is real, rigorous, and does not include Penis Envy among the five strains it tested.
What research shows
UnsupportedNo peer-reviewed study has quantified Penis Envy. Goff 2024 measured Blue Meanie, Creeper, B-Plus, Texas Yellow and Thai Cubensis, finding a 1.5-fold spread among them. The 2025 review that names Penis Envy as exceptionally potent states plainly that its strain descriptions come from non-academic, community-based reports.
This is not a claim that Penis Envy is ordinary. It is a claim that nobody has published a measurement either way. Absence of a measurement is not evidence of absence of an effect — and the reputation is widespread enough among growers to be worth testing. But a documented four-fold swing between flushes of one culture, and a more-than-tenfold swing between outside collections, means informal comparison cannot resolve a strain effect even in principle.
Goff 2024 (PMID 38220293); Kurzbaum 2025 (PMID 39997393); Bigwood & Beug 1982 (PMID 7201054)
Even within a named strain, content is not standardised. Goff's own secondary laboratory found precision improved only when several mushrooms were homogenised together first — a direct measure of how much individual fruiting bodies of the same strain differ.[8] Named strains are not pharmaceutical preparations with verified potency.
For science-backed comparisons of the main varieties, see P. cubensis Varieties: Golden Teacher, B+, Penis Envy, and More and Psilocybe cubensis Varieties: Golden Teacher, B+, and Penis Envy Compared. On the related claim that pale strains are stronger, see Albino Mushrooms and Psilocybin: Does Colour Affect Potency?.
- Pathway biochemistrycompleted
Four enzymes characterised and the reaction reconstituted outside the mushroom (Fricke 2017)
- Comparative genomics and phylogenycompleted
Genus-wide phylogenomics, cluster gene orders, molecular clock, and a five-species metabolome survey (Bradshaw 2024, Dörner 2022)
- Analytical quantification of alkaloid contentcurrent
Validated LC-MS/MS and UHPLC-MS methods applied to small, non-comparable sample sets across five decades (Goff 2024, Gotvaldová 2021/2022, Bigwood 1982)
- Controlled strain comparison under matched conditionsmissing
No study has grown the named varieties side by side on identical substrate and quantified them across multiple flushes
- Clinical study using the mushroom itselfmissing
All therapeutic psilocybin research uses synthetic compound; the species has never been the intervention in a clinical trial
- Pooled synthesis of potency datamissing
Nothing poolable — the published datasets differ in provenance, method, era and handling, and were never designed to be combined
The molecular biology of this species is genuinely well established: the pathway is characterised, the genome is sequenced, the phylogeny is resolved. What is not established is anything quantitative about the mushroom as a material — how much it contains, why that varies, or whether named varieties differ. The chemistry is strong; the agronomy has barely been attempted.
Fricke 2017 (PMID 28763571); Bradshaw 2024 (PMID 38194448); Goff 2024 (PMID 38220293); Kurzbaum 2025 (PMID 39997393)
Research Gap
What would make a strain potency claim meaningful
What would a study need to do to establish that one named P. cubensis variety is more potent than another?
The famous strains actually included
Golden Teacher and Penis Envy — the two varieties every potency discussion centres on — have never appeared in a published quantification.
Matched cultivation conditions
Identical substrate, temperature, humidity and harvest timing across all strains compared, since these are uncontrolled in every existing dataset.
Multiple flushes per strain
Enough harvests to clear the documented four-fold psilocybin swing and the psilocin rise from zero to maximum by flush four.
Genotype confirmation of strain identity
Strain labels are self-reported by cultivators, and DNA authentication work on curated Psilocybe collections has found even species-level labels unreliable.
Homogenised multi-mushroom samples
Goff's secondary laboratory demonstrated this improves precision — the technique is known and validated, it simply has not been applied at scale.
Validated quantification chemistry
LC-MS/MS and UHPLC-MS methods for these alkaloids are established and reproducible across laboratories. This piece is genuinely in place.
Goff 2024 (PMID 38220293); Bigwood & Beug 1982 (PMID 7201054); Kurzbaum 2025 (PMID 39997393)
Legal Status and Scientific Research Context
Psilocybe cubensis is a Schedule I controlled substance in the United States under the Controlled Substances Act, a classification denoting high abuse potential, no currently accepted medical use, and a lack of accepted safety under medical supervision. It is illegal in most countries under national narcotics laws, many aligned with the 1971 UN Convention on Psychotropic Substances, which scheduled psilocybin.
Two US states have since built regulated access programmes, and it is worth naming the measures correctly because they are frequently confused. Oregon's psilocybin services programme was created by Measure 109, passed in November 2020, which directed the Oregon Health Authority to license service centres and facilitators for supervised adult use; services began in 2023. Measure 110, passed at the same election, was a general drug-decriminalisation measure, not a psilocybin programme, and it was substantially rolled back by the legislature in 2024.
Colorado voters approved Proposition 122, the Natural Medicine Health Act, in November 2022, implemented through SB23-290. The first healing centre licence was issued in March 2025 and the first regulated session took place in June 2025; by early 2026 the state counted several dozen licensed centres. Several US cities have separately deprioritised enforcement. The legal landscape continues to change, and none of the above alters federal scheduling.
All current clinical research on therapeutic psilocybin uses synthetic psilocybin — chemically identical to the mushroom's compound, but manufactured to pharmaceutical specification. The trials at Johns Hopkins, NYU, Imperial College London and elsewhere test the molecule, not the mushroom. P. cubensis enters that story only as the organism whose biosynthetic pathway made efficient synthesis tractable.
Safety & Legal Context
CriticalPotency cannot be judged by appearance, strain name, or bruising
Concern
The measurements in this article span trace amounts to 19.9 mg/g psilocybin across published P. cubensis analyses. Within a single controlled culture, psilocybin varied four-fold between harvests with no trend, and psilocin was absent from early flushes entirely. Samples from outside sources varied by over a factor of ten between collections. The researchers who produced the largest identified survey describe this variability as posing an apparent risk of overdose.
What the research says
No visual feature — colour, size, density, or degree of blue bruising — gives a usable estimate of alkaloid content. Blue bruising in particular marks psilocybin that has already been converted to inactive oligomers, so reading intense blue as a sign of strength inverts the chemistry. Strain names carry no verified potency: two of the three most-discussed varieties have never been quantified in any peer-reviewed study.
Particularly relevant for: Identification risk extends well beyond potency. Several genera contain species that are seriously toxic and superficially similar to psilocybin-containing ones, and DNA authentication work has found species labels unreliable even within curated museum collections.
What to do
Psilocybin remains a Schedule I controlled substance under US federal law and is controlled in most jurisdictions. This article describes mycological, genomic and analytical research findings. It is not medical advice, and it is not guidance on obtaining, cultivating or using these mushrooms. Anyone considering psilocybin in a therapeutic context should speak with a qualified clinician about the regulated pathways that exist in their jurisdiction.
Bigwood & Beug 1982 (PMID 7201054); Gotvaldová 2022 (PMID 36430546); Gotvaldová 2021 (PMID 33119971); Kurzbaum 2025 (PMID 39997393)
The Bottom Line
Psilocybe cubensis is the world's most cultivated psilocybin mushroom, and its molecular biology is genuinely well characterised: four biosynthetic enzymes described by Fricke in 2017, a genus-wide phylogeny and cluster evolution mapped by Bradshaw in 2024, and five alkaloids quantified across tissue types by Gotvaldová in 2021. What is not characterised is the mushroom as a material. Compiled published analyses put psilocybin anywhere between trace amounts and 19.9 mg/g of dried tissue, with datasets separating by provenance rather than converging on a value; a single controlled culture swung four-fold between harvests with no trend. The only published strain comparison tested five varieties — and neither Golden Teacher nor Penis Envy was among them. The species is Schedule I in the US, and all clinical psilocybin research uses synthetic compound rather than the mushroom.
Frequently Asked Questions
Sources & References
- 1RTHM-00003·Bigwood, J et al. (1982). “Variation of psilocybin and psilocin levels with repeated flushes (harvests) of mature sporocarps of Psilocybe cubensis (Earle) Singer..” Journal of ethnopharmacology.Study breakdown →PubMed →↩
- 2RTHM-00471·Fricke, Janis et al. (2017). “Enzymatic Synthesis of Psilocybin..” Angewandte Chemie (International ed. in English).Study breakdown →PubMed →↩
- 3RTHM-00646·Nichols, David E (2020). “Psilocybin: from ancient magic to modern medicine..” The Journal of antibiotics.Study breakdown →PubMed →↩
- 4RTHM-00688·Gotvaldová, Klára et al. (2021). “Stability of psilocybin and its four analogs in the biomass of the psychotropic mushroom Psilocybe cubensis..” Drug testing and analysis.Study breakdown →PubMed →↩
- 5RTHM-00755·Dörner, Sebastian et al. (2022). “Genetic Survey of Psilocybe Natural Products..” Chembiochem : a European journal of chemical biology.Study breakdown →PubMed →↩
- 6RTHM-00762·Gotvaldová, Klára et al. (2022). “Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids..” International journal of molecular sciences.Study breakdown →PubMed →↩
- 7RTHM-00865·Bradshaw, Alexander J et al. (2024). “Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster..” Proceedings of the National Academy of Sciences of the United States of America.Study breakdown →PubMed →↩
- 8RTHM-00879·Goff, Roman et al. (2024). “Determination of psilocybin and psilocin content in multiple Psilocybe cubensis mushroom strains using liquid chromatography - tandem mass spectrometry..” Analytica chimica acta.Study breakdown →PubMed →↩
- 9RTHM-00932·Kurzbaum, Eyal et al. (2025). “Exploring Psilocybe cubensis Strains: Cultivation Techniques, Psychoactive Compounds, Genetics and Research Gaps..” Journal of fungi (Basel.Study breakdown →PubMed →↩