By Megan Nunn, PharmD 

Updated on November 15, 2023

 Medically reviewed by Suzanne Fisher, RD

Polycystic ovary syndrome (PCOS) is a common endocrine disorder marked by the following:

• High levels of androgens (sex hormones) in the ovaries

• The inability to ovulate¹

This article covers the research-based evidence behind some popular supplements that may improve PCOS symptoms and precautions to note if you decide to try them.

What Is PCOS?

PCOS affects up to 1 in 4 females during their reproductive years.¹ Symptoms associated with PCOS include the following:²

• Irregular menstrual cycles or skipping periods

• Acne

• Excess facial hair (hirsutism)

• Anxiety or depression

• Infertility

Lifestyle modifications like changing body composition and nutrition counseling can benefit some people with PCOS.³⁴

Pharmaceutically, PCOS is typically treated with metformin, other blood sugar medicines called thiazolidinediones, or birth control pills.⁵

Some supplements, including vitamins and fatty acids, may also provide a benefit.

What Supplements Are Used for PCOS?

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist (RD or RDN), pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Many vitamins and herbal supplements have been studied for their role in PCOS. Below is a brief survey of six popular ones that have evidence to back them up.

Curcumin

Curcumin is a compound found in turmeric, a spice used to flavor many dishes, including curries. It's also touted as a natural medicine and has shown some benefits for PCOS.⁶

Curcumin affects androgen receptor pathways and can decrease the expression of androgen hormones like testosterone. It can also stimulate ovulation.⁵

A review of five clinical trials concluded that curcumin improved blood sugar control in females with PCOS.⁶ Those who took curcumin had lower fasting blood sugar levels and responded better to insulin treatment than those who took a placebo (an inactive substance given to people in control groups in studies).

Curcumin has been studied in clinical trials for PCOS in varying doses, ranging from 80 milligrams (mg) daily to 500 mg three times a day.⁶

Studies took place over six to 12 weeks, so not enough is known about long-term safety or effectiveness.

Some possible adverse effects of curcumin include the following:⁶

Abdelazeem B, Abbas KS, Shehata J, et al. The effects of curcumin as dietary supplement for patients with polycystic ovary syndrome: An updated systematic review and meta-analysis of randomized clinical trials. Phytother Res. 2022;36(1):22-32. doi:10.1002/ptr.7274

• Nausea

• Indigestion

• Allergic reactions

 Turmeric powder and fresh turmeric.

Krisanapong Detraphiphat / Getty Images

Vitamin D

Studies show that up to 85% of females with PCOS have low levels of vitamin D, a hormone that helps maintain normal blood sugar levels.⁵ Vitamin D deficiency may be a risk factor for PCOS, although this conclusion is still controversial.⁷

Vitamin D has been studied for PCOS in doses such as 200 international units (IU) daily and 50,000 IU every two weeks.⁸

Taking high doses of vitamin D, such as 4,000 IU daily for at least 12 weeks, has improved the following levels in females with PCOS:⁹

• Blood sugar

• Lipids (fats in the blood)

• Testosterone (a hormone whose concentration is much higher in males compared to females)

Vitamin D also helps support healthy pregnancies by exerting similar effects as the hormone progesterone.¹⁰ And it decreases endometrial thickness, which can help regulate the menstrual cycle.¹¹

Like many supplements reviewed here, vitamin D has been studied for PCOS for only six months or less, meaning more research is needed.⁸

Omega-3 Fatty Acids

Omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in fatty fish like salmon and in supplement form. These fatty acids can improve insulin sensitivity.¹

Small, short-term studies have shown that omega-3 fatty acids benefit PCOS, but more robust clinical trials are needed to verify these effects.⁴ Studied dosages range from 900 to 4,000 mg daily for up to 24 weeks.¹²

The greatest evidence of benefit is for females who have PCOS plus either insulin resistance or high cholesterol.⁴ Omega-3 fatty acids improved these metrics but did not significantly affect testosterone levels or fasting blood sugar.

While omega-3 fatty acids aren't routinely recommended for females with PCOS, supplementing with them may be helpful for those over 40 with heart problems or symptoms like high triglycerides.¹

Side effects to watch for mainly affect the gastrointestinal tract and include the following:¹

• Nausea

• Gas

• Diarrhea

• Stomach pain

It's essential not to use omega-3 fatty acids when taking blood thinners like Jantoven (warfarin) or Eliquis (apixaban).¹

Cinnamon

Cinnamon can improve the following parameters in females with PCOS, according to a review of five clinical trials:¹³

• Insulin resistance (when muscle, fat, and liver cells don't respond well to insulin and can't easily take up glucose from your blood, causing the pancreas to produce more insulin)

• Blood sugar

• Cholesterol

Cinnamon is unlikely to reduce body weight or body mass index (BMI).¹³

Clinical trials have used 1,000 mg daily for eight weeks and 1,500 mg daily for six months.¹⁴ Researchers note that long-term studies are needed to determine the actual effect of cinnamon on PCOS.

Adverse effects that were seen in clinical trials of cinnamon for PCOS include:¹⁴

• Headache

• Heartburn

• Menstrual cramps

• Nausea

• Diarrhea

Inositol

Inositol is a sugar alcohol in high amounts in the brain and muscles.¹² While it has been referred to as "vitamin B8," it's not a vitamin. Inositol can help many aspects of PCOS, including regulating insulin levels and improving reproductive function.² It may also help with weight loss.¹⁵

Inositol was shown to be as effective as the gold-standard PCOS treatment, metformin, in an extensive review of 26 clinical trials.¹⁵ It has a low risk of side effects, according to this review.

Clinical trials have used 4,000 mg of myo-inositol (a form of inositol) in females undergoing in vitro fertilization with PCOS.¹⁶ This dose helped to:⁵

• Decrease androgen levels

• Restore ovulation

• Regulate the menstrual cycle

Of note, adding 50 mg of alpha-lactalbumin (α-LA) twice a day can enhance the effects of inositol supplementation and increase the likelihood of ovulation.¹⁷

CoQ10

Coenzyme Q10 (CoQ10) is an antioxidant found in heart, liver, and kidney cells.¹²

Supplemental doses of 100 mg daily for 12 weeks improved blood sugar and low-density lipoprotein (LDL, or "bad") cholesterol levels in females with PCOS.¹⁸

And 200 mg a day of CoQ10 for eight weeks improved markers of inflammation in a small study of 43 women with PCOS who were overweight or had obesity.¹⁹ Those who took CoQ10 had lower C-reactive protein (CRP) and interleukin-6 levels, which are elevated during inflammation.

Another clinical trial showed that adding CoQ10 to the prescription medicine clomiphene made it 6 times more likely for females with PCOS to get pregnant than if they took clomiphene alone.²⁰

Side effects of coQ10 include:²⁰

• Nausea

• Heartburn

• Diarrhea

Berberine

Berberine is a natural isoquinoline alkaloid (an organic compound) that comes primarily from plants like Oregon grape (Berberis aquifolium) and goldenseal.

Clinical trials have studied berberine in people with PCOS alone or in combination with medications like metformin.²¹ In these studies, berberine decreased insulin resistance, lowered lipid levels, and helped improve ovulation.

The effects of berberine, when used with metformin, have been shown to be somewhat synergistic (they help increase the effects of the medication). However, researchers caution that the quality of the included studies was fairly low, and the results must be interpreted carefully.

In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.

Summary

PCOS is a common endocrine disorder that affects up to 25% of females. Several dietary supplements have benefitted symptoms of PCOS, like high blood sugar or menstrual cycle abnormalities. Doses studied in clinical trials vary; discuss these supplements with your healthcare provider, pharmacist, or a registered dietitian for best results and for guidance on optimizing therapy.

Also, remember that most studies reviewing supplements' effects on PCOS were small and lasted six months or less. More robust data is still needed before these supplements can be fully recommended.