Maitake for PCOS: Can It Help Restore Ovulation?

Maitake & PCOS

76.9% ovulation rate

In 80 PCOS patients across three Japanese fertility clinics, maitake SX-fraction achieved a 76.9% ovulation rate as standalone therapy. For women who had already failed Clomid, adding maitake produced ovulation in 75%.

Chen et al., Journal of Alternative and Complementary Medicine, 2010

80 patients

across 3 clinics, up to 12-week open trial

75% rescue

of Clomid-resistant patients ovulated with maitake added

2025

first systematic review to formally include maitake in PCOS evidence

Chen et al., Journal of Alternative and Complementary Medicine, 2010

View as image ↗

PCOS is the leading cause of anovulatory infertility, affecting an estimated 5 to 10 percent of women of reproductive age. Most never ovulate consistently without medical intervention. In 2010, a Japanese research team led by Chen enrolled 80 PCOS patients across three fertility clinics and tested whether a maitake mushroom extract could restore ovulation in PCOS, comparing it head-to-head against clomiphene citrate (Clomid), the standard ovulation drug at the time. The maitake group achieved a 76.9% ovulation rate. More remarkably, 75% of the women who had already failed Clomid began ovulating when maitake was added as a rescue treatment.^[1]

Maitake mushroom is more commonly studied for its immune and blood sugar effects. But that single clinical trial placed it in an unexpected category: a potential option for women with PCOS seeking to restore ovulation. This article covers what Chen's team found, what a 2025 systematic review confirmed, and what one unblinded trial can and cannot tell you.

What PCOS Actually Does to Ovulation (It Starts With Insulin)

Understanding why maitake might work requires understanding what PCOS does to the hormonal system.

In most women with PCOS, cells throughout the body respond poorly to insulin, a state called insulin resistance. The body compensates by releasing more insulin to achieve the same blood sugar effect. Those elevated insulin levels then do something the ovaries are not designed to handle: they signal ovarian cells to overproduce androgens, primarily testosterone. At the same time, high circulating insulin suppresses SHBG (sex hormone-binding globulin), the protein that normally binds testosterone and keeps it inactive. The result is a buildup of free, biologically active testosterone in the bloodstream.

This androgen excess disrupts the normal follicular development cycle. Each month, follicles in the ovaries begin to grow toward the maturation point that triggers ovulation. In PCOS, that growth stalls. Partially-developed follicles accumulate without ever releasing an egg. Ovulation stops, sometimes for months or years at a time.

This mechanism is why insulin-sensitizing drugs are now part of standard PCOS care. Metformin, a medication developed for type 2 diabetes, is commonly prescribed alongside ovulation induction therapy. The logic is direct: reduce insulin levels, reduce the androgen signal driving follicular arrest, give the follicular cycle a better chance to complete.

Maitake enters this picture through a specific water-soluble compound extracted from the mushroom called SX-fraction, which researchers have studied as an insulin sensitizer. The full mechanistic pathway, from insulin resistance through androgen excess to anovulation, is covered in Maitake and Insulin-Driven Hormonal Imbalance in PCOS. The clinical question here is simpler: does that insulin-sensitizing effect actually restore ovulation in real patients? That is what Chen's trial set out to determine.

The 2010 Trial: A Mushroom Extract Tested Against Clomid in 80 Patients

Chen and colleagues enrolled 80 Japanese women with confirmed PCOS diagnosis across three reproductive medicine clinics. Participants were assigned to receive either maitake SX-fraction extract (MSX) or clomiphene citrate (CC) as primary ovulation treatment for up to 12 weeks.^[1]

The maitake formulation was specific. Each tablet contained 18mg of SX-fraction plus 250mg of dried maitake powder. SX-fraction is a distinct water-soluble compound (technically a glycoprotein, meaning a protein with sugar chains attached) extracted from maitake. It is not the same as D-fraction, the immune-focused compound found in most standard maitake supplements. The SX-fraction formulation was the operative ingredient in this trial. The comparison arm received standard clomiphene citrate doses.

Primary results by patient:

• MSX group (26 patients): 76.9% ovulated (20 out of 26)
• CC group (31 patients): 93.5% ovulated (29 out of 31)

Clomid performed better. But the maitake result, 76.9%, represents three-quarters of patients achieving ovulation from a mushroom extract. The full trial methodology and data breakdown are covered in Maitake and Polycystic Ovary Syndrome: Clinical Trial Results.

By-Patient vs. By-Cycle Rates: Why Both Numbers Matter

The by-patient rate measures whether a woman ovulated at least once during the trial. The by-cycle rate measures how often individual menstrual cycles produced ovulation across the whole study period. By-cycle is a stricter standard.

By-cycle results:

• MSX: 41.7%
• CC: 69.9%

Both groups show lower cycle-level rates because not every cycle during the 12-week period produced ovulation, even for women who did eventually ovulate at some point. This is expected in PCOS treatment trials. The per-patient rate is the primary clinical endpoint; the per-cycle rate reflects how consistently and reliably that ovulation occurred once treatment started.

The SX-fraction compound responsible for these effects, and what distinguishes it from generic maitake powder, is detailed in Maitake and Ovarian Function: SX-Fraction Research in PCOS Models.

The Finding That Matters Most: 75% of Clomid Failures Ovulated With Maitake Added

The headline ovulation rate is notable. But it is not the most clinically significant result in the trial.

After the initial monotherapy phase, women who had not responded to their assigned treatment were offered combination rescue therapy. The outcomes split as follows:^[1]

• MSX group non-responders given Clomid plus MSX: 100% ovulated
• CC group non-responders given MSX added to Clomid: 75% ovulated

That second number is the one with the most clinical relevance, and it is almost never mentioned in consumer health coverage.

Clomid resistance, defined as failing to ovulate despite adequate dosing over multiple cycles, affects an estimated 15 to 40% of PCOS patients who try it. For these women, the standard next steps move up in invasiveness: injectable gonadotropins, intrauterine insemination, or IVF. The fact that adding a mushroom extract produced ovulation in 75% of this resistant group is a striking finding, and it is the primary reason this trial attracted attention in integrative reproductive medicine.

The mechanism for why combination therapy works is likely additive rather than redundant. Clomid acts at the hypothalamus, blocking estrogen receptors to trigger higher FSH and LH release, which drives egg maturation from above. Maitake works upstream: by improving insulin sensitivity, it may reduce the androgen excess that was preventing follicles from completing development in the first place. Two different entry points into the PCOS cycle. The side-by-side mechanism comparison is in Maitake vs. Clomid for PCOS: A Comparison Study.

The 2023 Guideline Update That Reframes the Comparison

Chen's 2010 trial compared maitake against Clomid. That framing was appropriate in 2010, when clomiphene citrate was the established first-line ovulation induction treatment for PCOS in most international guidelines.

In 2023, those guidelines changed. Letrozole, an aromatase inhibitor originally developed as a breast cancer drug, is now recommended as the preferred first-line treatment for ovulation induction in PCOS. Letrozole produces higher ovulation rates and live birth rates than Clomid, with fewer adverse effects, particularly less risk of endometrial thinning and fewer multiple pregnancies.

This guideline change reframes the maitake data in two ways. First, the benchmark comparator has shifted. Maitake vs. Clomid is real data, but Clomid is no longer the primary standard. Second, the category of "Clomid-resistant" patients, where maitake showed its most compelling rescue result, is now smaller than in 2010, because many patients who previously would have been tried on Clomid first are now starting with letrozole.

Whether maitake would show a similar rescue effect for patients who fail letrozole is simply not known. No study has examined this. The 2010 rescue data is a real finding, but it cannot be extrapolated to a clinical context that did not exist when the trial was conducted.

The Weight Connection: Why Maitake's Anti-Obesity Effects May Matter for PCOS

Between 50 and 80 percent of women with PCOS are overweight or obese. This overlap is not coincidental. Fat tissue, particularly abdominal fat, amplifies insulin resistance and independently drives androgen production. In overweight women with PCOS, even modest weight loss, around 5 to 10 percent of body weight, can restore ovulation in a meaningful proportion.

Jiang and colleagues published research in 2021 showing that maitake reduced fat accumulation in mice on a high-fat diet by modulating lipid metabolism through the ceramide pathway, a fat-storage signaling system involved in metabolic disease.^[3] When the ceramide pathway was disrupted by maitake compounds, obesity-related fat gain was reduced in the animals.

This was animal research, not a human trial. But for PCOS patients where obesity compounds insulin resistance, maitake's metabolic breadth may add to the insulin-sensitizing effects seen in the clinical ovulation data. If maitake reduces both insulin resistance and fat accumulation, the combined impact on androgen levels could be larger than either effect alone would suggest.

That remains a hypothesis assembled from preclinical lipid data and a clinical ovulation trial. No study has examined maitake specifically for weight management in PCOS patients.

The 2025 Systematic Review: First Formal Academic Validation

For fifteen years after the Chen 2010 trial, maitake for PCOS appeared almost nowhere in peer-reviewed literature. No independent team replicated the trial. No systematic review included it.

In 2025, Wani and Shaikh published a systematic review in JBRA Assisted Reproduction examining natural and herbal treatments for PCOS.^[2] Maitake was formally included. The review confirmed the Chen 2010 ovulation data (76.9% vs 93.5% for Clomid), noted maitake's effects on blood glucose, blood pressure, and serum lipids, and documented both the D-fraction immune bioactive and the metabolic effects associated with other fractions.

This was the first time maitake appeared in a systematic review specifically examining PCOS natural treatments. It does not change the underlying evidence base: the clinical case still rests on Chen 2010. But it means maitake for PCOS now exists within the formal academic PCOS literature, making it findable for reproductive medicine researchers who might conduct future studies. That is not a small thing. Evidence bases grow when findings get cited.

What One Open-Label Trial Cannot Tell You

The Chen 2010 study has a methodological limitation that advocates for natural PCOS treatments consistently understate: it was an open-label trial.^[1] Both the patients and the clinicians knew which treatment each participant was receiving. There was no placebo comparison and no blinding.

Open-label trials are vulnerable to expectation effects and differential care. Women who know they are taking a natural mushroom extract instead of the standard pharmaceutical may have different psychological responses, different adherence patterns, or different levels of clinical engagement. These factors can influence hormonal and reproductive outcomes in ways that properly blinded trials control for.

The trial also drew entirely from Japanese fertility clinics. The patient population, including diet, average BMI, PCOS phenotype distribution, and baseline hormone profiles, may differ meaningfully from women with PCOS in other countries. How well the results generalize beyond this population is unknown.

Sample size matters too. Eighty patients is enough to detect a large treatment effect, but not enough to be confident the numbers hold up in a larger or more diverse population. The per-group sample sizes were small: 26 in the MSX arm and 31 in the Clomid arm.

Most critically: in the fifteen years since publication, no independent team has attempted a replication trial. One open-label study from one country, never replicated in more than a decade, is an interesting clinical signal. It is not a confirmed treatment effect.

The honest interpretation of the maitake PCOS evidence is this: the trial points in one direction compellingly. The 2025 systematic review adds formal weight. But a single unblinded trial is a hypothesis, not proof.

The Bottom Line

A 2010 clinical trial in 80 Japanese PCOS patients remains the only human evidence for maitake's effect on ovulation. The trial found a 76.9% ovulation rate with maitake SX-fraction monotherapy and a 75% rescue rate for women who had previously failed Clomid. A 2025 systematic review formally included these findings in the PCOS natural treatment evidence base. The trial was open-label and has not been replicated; this is an interesting clinical signal but not a confirmed treatment effect.

Frequently Asked Questions

Can maitake mushroom help with PCOS?

One clinical trial in 80 PCOS patients found maitake SX-fraction achieved a 76.9% ovulation rate as standalone treatment, and a 2025 systematic review formally included these results in the PCOS natural treatment evidence base. This is the only human trial studying maitake in PCOS, and it was open-label rather than double-blind. The evidence is preliminary; maitake is not an established PCOS therapy, but the single available trial shows a clinically meaningful effect on ovulation.

Does maitake mushroom help restore ovulation?

In the Chen 2010 trial, 76.9% of PCOS patients taking maitake SX-fraction extract ovulated during the 12-week study period, compared to 93.5% for Clomid. The more striking result was in the rescue phase: 75% of women who had previously failed Clomid treatment ovulated when maitake was added. These are the only published human data on maitake and ovulation restoration in PCOS. The trial was not double-blinded, and no independent team has since replicated it.

Is maitake mushroom good for hormonal imbalance?

Maitake contains a specific compound called SX-fraction, a water-soluble extract studied as an insulin sensitizer. In PCOS, insulin resistance drives elevated androgen production that disrupts hormonal balance and prevents ovulation. By reducing insulin resistance, maitake's SX-fraction may lower the androgen excess at the root of PCOS hormonal disruption. The clinical evidence for this comes from one open-label ovulation trial; no human study has directly measured androgen levels before and after maitake treatment in PCOS patients.

What natural supplements help PCOS ovulation?

The most studied natural options for PCOS ovulation are myo-inositol and D-chiro-inositol, with multiple randomized controlled trials supporting their use. Maitake SX-fraction has one open-label trial showing a 76.9% ovulation rate; N-acetyl cysteine (NAC) has several small trials. All are less well-evidenced than pharmaceutical ovulation induction. A 2025 systematic review by Wani and Shaikh formally included maitake alongside other natural treatments in the PCOS evidence base.

Can maitake replace Clomid for PCOS?

Based on the available data, maitake is less effective than Clomid as standalone treatment: 76.9% vs 93.5% patient ovulation rate in the one direct comparison trial. Clomid itself now has a lower priority than letrozole, which is the current first-line recommendation in international PCOS guidelines as of 2023. Maitake's most supported role is not as a Clomid replacement but as an adjunct for Clomid-resistant patients, where adding maitake produced ovulation in 75% of treatment failures in Chen's trial.

Sources & References

1. 1RTHM-00330·Chen, Jui-Tung et al. (2010). “Maitake mushroom (Grifola frondosa) extract induces ovulation in patients with polycystic ovary syndrome: a possible monotherapy and a combination therapy after failure with first-line clomiphene citrate..” Journal of alternative and complementary medicine (New York.Study breakdown →PubMed →↩
2. 2RTHM-02208·Wani, Rashmi et al. (2025). “Healing with Herbs: A Systematic Review of Natural Treatments for Polycystic Ovary Syndrome..” JBRA assisted reproduction.Study breakdown →PubMed →↩
3. 3RTHM-01369·Jiang, Xue et al. (2021). “Anti-obesity effects of Grifola frondosa through the modulation of lipid metabolism via ceramide in mice fed a high-fat diet..” Food & function.Study breakdown →PubMed →↩