Fertility Supplements for Women: What the Evidence Supports

The only supplement with strong evidence for women trying to conceive is folic acid, 400 mcg a day, started at least one month before pregnancy, and its proven job is preventing neural tube defects rather than boosting fertility.¹² Other popular fertility ingredients, such as CoQ10, myo-inositol, and antioxidant blends, have low to very low quality evidence so far.³⁴

This page grades the common ingredients by evidence, explains what the research actually found, and lists questions to bring to your clinician. We have not used any fertility products; product details come from brand websites, and health claims come only from public health agencies and systematic reviews.

Evidence at a glance: common fertility supplement ingredients

Folic acid: the established piece

CDC's planning steps for pregnancy include getting 400 micrograms of folic acid daily, because having enough folic acid at least one month before and during early pregnancy can help prevent serious birth defects of the brain and spine.⁹ USPSTF gives a daily supplement of 400 to 800 mcg an A recommendation for anyone planning or capable of pregnancy.²

Timing is the reason it belongs on a "trying to conceive" list. The neural tube closes about 26 to 28 days after fertilization, often before a pregnancy is recognized.¹⁰¹¹ A prenatal vitamin with at least 400 mcg of folic acid is the simplest way to cover it.⁸ See folic acid before pregnancy for when to start and our best prenatal vitamins page for label-checked options.

What folic acid does not do is increase fertility in people whose folate status is already adequate. Promises that it boosts fertility, energy, or hair growth are unproven unless tied to a diagnosed deficiency.⁵ Read the full graded list in folic acid benefits.

Antioxidants, CoQ10, and other "egg quality" ingredients

Many fertility blends for women center on antioxidants. The idea is that they reduce oxidative stress. The best summary of the trials is a Cochrane systematic review that compared oral antioxidants, including combinations, N-acetylcysteine, melatonin, L-arginine, myo-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D with calcium, CoQ10, and omega-3 fatty acids, against placebo or standard care in subfertile women.³

What it found:

• Live birth: the authors were uncertain whether antioxidants improve live birth, because the evidence was very low quality.³
• Clinical pregnancy: low-quality evidence suggested antioxidants may be associated with higher clinical pregnancy rates, with moderately high inconsistency between trials.³
• Harms: adverse effects were poorly reported; the review found no clear increase in miscarriage, multiple pregnancy, stomach upset, or ectopic pregnancy, but again on low-quality evidence.³
• Conclusion: the authors wrote that there is limited evidence in support of supplemental oral antioxidants for subfertile women.³

Two points matter for readers. First, these trials were in subfertile women, many undergoing fertility treatment, so they say little about people who are not having trouble conceiving.³ Second, the problems were poor reporting of methods, imprecision, and inconsistency, which means future trials could change the picture.³

Myo-inositol for PCOS

Inositol products are marketed for polycystic ovary syndrome (PCOS), cycle regularity, and egg quality. A Cochrane review included 13 trials with 1,472 subfertile women with PCOS, mostly using myo-inositol before IVF.⁴

The review rated the evidence low to very low quality. It was uncertain whether myo-inositol improves live birth rates or clinical pregnancy rates compared with standard treatment, and an apparent drop in miscarriage disappeared when one unusual trial was removed.⁴ Live birth and adverse events were often not reported.⁴

If you have PCOS, inositol is a reasonable topic to raise with a reproductive endocrinologist. It should not replace a diagnosis and treatment plan.

Iodine, iron, and the rest of a prenatal

If you are going to take one supplement while trying to conceive, a prenatal vitamin is the practical choice, because it bundles folic acid with other nutrients pregnancy needs. A few to check on the label:

NIH notes that only about half of prenatal multivitamins sold in the United States contain iodine, so it is worth checking.⁶ Gummy prenatals usually cannot hold the same amount of iron as tablets or capsules.⁸

What else helps when planning a pregnancy

CDC's planning steps put supplements in context. Besides folic acid, they include talking to a healthcare provider about your health history, stopping alcohol, smoking, and certain drugs, avoiding toxic substances, reaching a healthy weight, learning your family history, and looking after mental health.⁹ CDC notes that trouble getting pregnant is one reason a clinician might refer you for genetic counseling.⁹

These steps have broader support than any fertility blend. A supplement cannot make up for an untreated medical condition or a medicine that needs review.

How to judge a fertility supplement label

• Check the folate line. Look for folic acid in parentheses and at least 400 mcg if this product is replacing your prenatal.⁵⁸ Some fertility-branded prenatals, such as FullWell's prenatal, use methylfolate and folinic acid instead of folic acid.¹² CDC's NTD recommendation is specifically folic acid.⁷ Our prenatal vitamins with methylfolate page explains the tradeoff.
• Add up overlap. If you take a prenatal plus a fertility blend, total the folic acid and vitamin A. The adult folic acid upper limit is 1,000 mcg from supplements and fortified foods.⁵ ACOG warns against doubling prenatal doses because of vitamin A.⁸
• Treat "clinically proven" as a company claim. FDA does not approve supplements for safety and effectiveness before they are sold; companies are responsible for that.¹³
• Watch for proprietary blends. A blend lists a total weight, not how much of each ingredient you get, which makes it hard to compare with trial doses.

Questions to ask your clinician

1. Should I start a prenatal vitamin now, and does mine have at least 400 mcg of folic acid?⁸
2. Do I have a risk factor that calls for a higher prescribed folic acid dose?¹⁴⁷
3. Should I be tested for anything (thyroid, iron, B12, PCOS) before adding supplements?
4. Is there evidence for this specific ingredient in someone like me, and could it interact with my medicines?¹⁵
5. If we have been trying for a while, when should we see a fertility specialist?

Partners matter too. Male fertility supplements have their own evidence problems; see folic acid for men and our Beli review.

This article is for general education and is not medical advice. Doses and needs differ from person to person, so talk with your clinician or pharmacist about your situation. Read our editorial policy and medical disclaimer.