The fertility supplement market has exploded into a multi-billion dollar industry, and for good reason: people trying to conceive are motivated, hopeful, and willing to invest in anything that might improve their chances. But motivation and hope can make you vulnerable to marketing that outpaces the science.
In this guide, we review the clinical evidence behind the most popular fertility supplements, separating what genuinely works from what is mostly hype. We categorize each supplement by the strength of its evidence and provide practical dosage guidance based on published research.
A Reality Check on Fertility Supplements
Before diving into specific supplements, a few important principles:
- Supplements are not a substitute for medical evaluation. If you have a diagnosable fertility condition (blocked tubes, severe male factor infertility, anovulation due to PCOS), supplements alone will not overcome these barriers. Get tested first.
- Most supplements support fertility rather than creating it. They optimize the conditions for conception: improving egg quality, supporting hormonal balance, and creating a favorable uterine environment. They do not override fundamental biological limitations.
- Quality matters enormously. The supplement industry is poorly regulated. Products can contain less (or more) of an ingredient than stated, and may contain contaminants. Choose supplements that are third-party tested (look for USP, NSF, or ConsumerLab verification).
- Give them time. Egg maturation takes approximately 90 days. Most supplements need at least two to three months of consistent use before their effects on egg quality are realized.
Strong Evidence: Supplements That Work
Folate / Folic Acid
Evidence level: Essential
Folate is the most well-established supplement for anyone trying to conceive. It is critical for DNA synthesis, cell division, and neural tube development in early pregnancy. Adequate folate intake before conception reduces the risk of neural tube defects by approximately 50 to 70 percent.
Recommended dose: At least 400 mcg daily; 800 mcg for those at higher risk of neural tube defects. Methylfolate (5-MTHF) is the bioactive form and is recommended over folic acid for people with MTHFR gene variants that impair folic acid metabolism.
When to start: At least one month before trying to conceive, ideally three months.
Prenatal Multivitamin
Evidence level: Essential
A comprehensive prenatal vitamin provides a baseline of nutrients critical for fertility and early pregnancy, including folate, iron, iodine, vitamin B12, and zinc. Multiple observational studies associate regular prenatal vitamin use with improved fertility outcomes and reduced time to pregnancy.
What to look for: At least 400 mcg folate (preferably methylfolate), 150 mcg iodine, 27 mg iron, adequate B12, and vitamin D. Avoid prenatals with excessive vitamin A (retinol form), which can be harmful in early pregnancy. Choose one with third-party testing verification.
Vitamin D
Evidence level: Strong
Vitamin D deficiency is remarkably common and has been associated with reduced fertility in multiple studies. Research links adequate vitamin D levels to improved IVF outcomes, healthier pregnancy rates, and better overall reproductive function. Vitamin D receptors are present throughout the reproductive tract, including the ovaries and endometrium.
Recommended dose: 1,000 to 4,000 IU daily, depending on your baseline level. Ideally, have your vitamin D level tested (25-hydroxyvitamin D blood test) and aim for a level of 40 to 60 ng/mL. Many fertility specialists recommend 2,000 IU daily as a standard maintenance dose.
Promising Evidence: Worth Considering
Coenzyme Q10 (CoQ10)
Evidence level: Promising
CoQ10 is an antioxidant that plays a critical role in cellular energy production. As eggs mature, they require enormous amounts of energy, and CoQ10 levels naturally decline with age. Animal studies show that CoQ10 supplementation can improve egg quality and mitochondrial function in aging oocytes. Human studies are more limited but suggest that CoQ10 may improve egg quality and IVF outcomes, particularly for people over 35.
Recommended dose: 200 to 600 mg daily. The ubiquinol form is more bioavailable than ubiquinone. Higher doses (400 to 600 mg) are often recommended for people over 35 or those with diminished ovarian reserve.
When to start: At least two to three months before conception attempts, as egg maturation takes approximately 90 days.
Omega-3 Fatty Acids (DHA/EPA)
Evidence level: Promising
Omega-3 fatty acids, particularly DHA and EPA from fish oil, have anti-inflammatory properties and support hormonal balance. Studies suggest that omega-3 supplementation may improve egg quality, support endometrial receptivity, and reduce the risk of preterm birth. DHA is also critical for fetal brain and eye development during pregnancy.
Recommended dose: 500 to 1,000 mg of combined DHA and EPA daily. Choose a fish oil supplement that is third-party tested for mercury and other contaminants, or use an algae-based DHA supplement for a plant-based option.
Myo-Inositol
Evidence level: Promising (especially for PCOS)
Myo-inositol is a B-vitamin-like compound that acts as a second messenger in insulin signaling. For people with PCOS, myo-inositol has been shown in multiple randomized controlled trials to improve insulin sensitivity, restore ovulatory cycles, and improve egg quality. It is one of the most well-studied supplements specifically for PCOS-related fertility challenges.
Recommended dose: 2,000 to 4,000 mg daily, often combined with D-chiro-inositol in a 40:1 ratio (the physiological ratio found in the body). This is typically taken as a powder dissolved in water.
Iron
Evidence level: Promising
Iron deficiency is common among people of reproductive age, and the Nurses' Health Study found that women who took iron supplements had a significantly lower risk of ovulatory infertility. Iron supports oxygen transport, energy production, and healthy blood volume, all of which are critical during conception and early pregnancy.
Recommended dose: 18 to 27 mg daily from food and supplements combined. Have your ferritin level tested; if it is below 30 ng/mL, supplementation is particularly important. Take iron with vitamin C to improve absorption and on an empty stomach if tolerated.
Limited Evidence: Proceed With Caution
DHEA (Dehydroepiandrosterone)
Evidence level: Limited and specific
DHEA is a hormone precursor that the ovaries convert to testosterone and estrogen. Some studies suggest that DHEA supplementation may improve ovarian response in people with diminished ovarian reserve, particularly before IVF. However, DHEA is a hormone, not a typical supplement, and it can have significant side effects including acne, hair growth, and voice changes.
Important: DHEA should only be taken under medical supervision, typically by a reproductive endocrinologist who is monitoring your hormone levels. It is not recommended as a self-prescribed supplement for general fertility support.
Vitex (Chasteberry)
Evidence level: Limited
Vitex agnus-castus has been used traditionally to regulate menstrual cycles and support luteal phase function. Some small studies suggest it may help with cycle regularity and mild PMS symptoms, potentially by modulating prolactin and progesterone. However, the evidence is not strong enough to make confident claims about fertility improvement.
Caution: Vitex can interact with hormonal medications and may worsen symptoms for some people with PCOS. Discuss with your healthcare provider before starting.
Royal Jelly
Evidence level: Very limited
Royal jelly is marketed aggressively for fertility, but human clinical evidence is sparse. A few small studies suggest possible benefits for egg quality, but the research is insufficient to draw meaningful conclusions. If you choose to try royal jelly, be aware of allergy risks (especially if you are allergic to bee products) and buy from a reputable source.
Evening Primrose Oil
Evidence level: Very limited
Evening primrose oil is commonly recommended to improve cervical mucus quality during the first half of the menstrual cycle. The theory is that its gamma-linolenic acid (GLA) content supports mucus production. However, there are no well-designed clinical trials supporting this use. If you try it, use it only during the follicular phase (from period to ovulation) and discontinue after ovulation, as some practitioners believe it may cause uterine contractions.
Supplements for Male Fertility
If you are using a partner's sperm rather than donor sperm, his supplement regimen matters too. Sperm development takes approximately 72 to 90 days, so supplements should be started at least three months before attempting conception.
Strong Evidence for Male Fertility
- Zinc: 15 to 30 mg daily. Zinc is essential for testosterone production and sperm development. Multiple studies link zinc deficiency to reduced sperm count and motility.
- Folate: 400 to 800 mcg daily. Folate supports DNA integrity in sperm. Low folate levels have been associated with increased sperm DNA fragmentation.
- Vitamin C: 500 to 1,000 mg daily. A potent antioxidant that protects sperm from oxidative damage. Studies show improvement in sperm count, motility, and morphology with vitamin C supplementation.
- CoQ10: 200 to 400 mg daily. Supports mitochondrial energy production in sperm, which is critical for motility. Multiple studies show improved sperm parameters with CoQ10 supplementation.
Promising Evidence for Male Fertility
- Selenium: 55 to 200 mcg daily. An antioxidant that supports sperm formation and motility. Often combined with vitamin E in studies showing improved sperm quality.
- L-Carnitine: 1,000 to 3,000 mg daily. Supports sperm energy metabolism and has shown improvement in motility in several studies.
- Vitamin E: 200 to 400 IU daily. Works synergistically with selenium and vitamin C to protect sperm from oxidative damage.
- Ashwagandha: 300 to 600 mg daily. An adaptogenic herb with some evidence for improving sperm count, motility, and testosterone levels in men with stress-related fertility issues.
Jessica's Pick for Fertility Supplements
I spent months researching supplements before my second pregnancy — CoQ10, folate, vitamin D, the works. What I love about the Her Success Kit is that it bundles a supplement pack formulated specifically for TTC, so you're not juggling six different bottles from Amazon and wondering if you got the right forms. I took them for two months before we started trying for Marco.
What to Avoid
Certain supplements and substances can actually harm fertility:
- High-dose vitamin A (retinol): More than 10,000 IU daily of preformed vitamin A can cause birth defects. Use beta-carotene instead, which the body converts to vitamin A as needed.
- Herbal blends without clear ingredients: Many fertility supplements contain proprietary blends that do not disclose individual ingredient amounts. Without transparency, you cannot evaluate safety or efficacy.
- Excessive caffeine: While moderate caffeine intake (under 200 mg daily, about one 12-ounce cup of coffee) appears safe during conception, high caffeine consumption has been associated with reduced fertility and increased miscarriage risk.
- Alcohol: Even moderate alcohol consumption can impair fertility. Complete abstinence during active conception attempts is the safest approach.
- NSAIDs around ovulation: Ibuprofen and similar medications can interfere with ovulation if taken around the time of the LH surge. Use acetaminophen (Tylenol) instead if pain relief is needed during your fertile window.
Building Your Supplement Protocol
Based on the evidence reviewed above, here is a practical supplement protocol organized by priority:
Essential (Everyone Trying to Conceive)
- Prenatal multivitamin with methylfolate (400 to 800 mcg)
- Vitamin D (2,000 IU daily or as directed by blood test results)
- Omega-3 DHA/EPA (500 to 1,000 mg daily)
Recommended (Especially If Over 35)
- CoQ10 ubiquinol (200 to 600 mg daily)
- Additional iron if ferritin is below 30 ng/mL
Condition-Specific
- Myo-inositol (2,000 to 4,000 mg daily) if you have PCOS
- DHEA (under medical supervision only) if you have diminished ovarian reserve
When to Start and How Long to Take Them
Timing matters because egg development takes approximately 90 days from the earliest stages to ovulation:
- Prenatal vitamin: Start at least one month before trying to conceive, ideally three months.
- CoQ10 and antioxidants: Start at least two to three months before your first insemination attempt to allow time for impact on egg quality.
- Vitamin D: Start immediately and continue through pregnancy. Have your levels checked to determine if you need a higher loading dose.
- Myo-inositol (for PCOS): Start two to three months before conception attempts. Some people see improvements in cycle regularity within the first month.
- Male supplements: Start at least three months before planned conception, as sperm development takes 72 to 90 days.
Continue all supplements through active conception attempts and into early pregnancy (except those specifically contraindicated during pregnancy, like DHEA). Discuss your supplement protocol with your healthcare provider, especially if you are taking medications or have underlying health conditions.