The supplements with the strongest evidence for supporting fertility include folic acid, vitamin D, CoQ10, omega-3 fatty acids, and a handful of targeted nutrients for sperm health. Most fertility specialists recommend starting a supplement routine one to three months before trying to conceive, since both egg and sperm development take roughly 90 days from start to finish. That window gives nutrients time to make a measurable difference.
What you take depends partly on whether you’re focused on egg quality, sperm quality, hormonal balance, or a combination. Here’s what the evidence supports for each.
Folic Acid: The Non-Negotiable Starting Point
Every woman capable of becoming pregnant should get 400 micrograms (mcg) of folic acid daily. The CDC recommends this as a baseline because folic acid is the only form of folate proven to prevent neural tube defects, which are serious birth defects of the brain and spine. These defects develop very early in pregnancy, often before you even know you’re pregnant, which is why timing matters so much.
Start taking folic acid at least one month before conception and continue through the first trimester. If you’ve had a previous pregnancy affected by a neural tube defect, the recommended dose jumps to 4,000 mcg daily, starting a month before conception. Most prenatal vitamins contain the standard 400 to 800 mcg dose, so check your label before adding a separate supplement.
Vitamin D and Pregnancy Rates
Vitamin D plays a larger role in fertility than most people realize. Several studies have found that blood levels of 30 ng/mL or higher are associated with significantly higher pregnancy rates. A meta-analysis of women undergoing fertility treatments found that those above this threshold had higher live birth rates than women with lower levels.
Many people are deficient without knowing it, especially those who live in northern climates, spend most of their time indoors, or have darker skin. A simple blood test can tell you where you stand. If your levels are low, supplementation with vitamin D3 can bring them up over the course of several weeks.
CoQ10 for Egg Quality
CoQ10 is an antioxidant your body produces naturally, but levels decline with age. It plays a key role in cellular energy production, which matters because eggs are among the most energy-demanding cells in the body. For women over 35, many reproductive endocrinologists recommend 300 to 600 mg of CoQ10 daily, split into two or three doses, for at least 8 to 12 weeks before trying to conceive or starting IVF.
The same dosage range applies to women over 40. The ubiquinol form of CoQ10 is more easily absorbed than the ubiquinone form, so you can often take a lower dose to get the same effect. If you’re already taking a prenatal vitamin, check whether it includes CoQ10, since most don’t.
Omega-3 Fatty Acids
Omega-3s support fertility through several pathways: they help regulate hormones involved in ovulation, increase blood flow to the uterus, reduce systemic inflammation, and may improve embryo implantation. A 2019 study tracking 900 women across more than 2,500 menstrual cycles found that women taking an omega-3 supplement were nearly twice as likely to conceive in a given cycle compared to those who didn’t.
A common recommendation is 1,000 mg of omega-3 fatty acids daily from purified fish oil, which provides the most bioavailable form of DHA. Both partners can benefit from this one.
Inositol for PCOS-Related Fertility Issues
If you have polycystic ovary syndrome (PCOS), inositol is one of the most studied supplements for restoring ovulation. Two forms matter here: myo-inositol and D-chiro-inositol. Research has found that combining them in a 40:1 ratio (myo-inositol to D-chiro-inositol) closely mirrors the body’s natural balance and produces the best results for reversing PCOS symptoms, including irregular ovulation.
Clinical studies in women with PCOS have confirmed that this ratio improves ovulatory function. Most formulations designed for PCOS already use the 40:1 ratio, so look for that on the label. Inositol is generally well tolerated and is sometimes described as having insulin-sensitizing effects similar to certain medications used for PCOS, but without the same side effect profile.
Supplements for Sperm Health
Male factor issues contribute to roughly half of all infertility cases, so what your partner takes matters just as much. Several nutrients have specific evidence behind them for improving sperm count, motility, and quality.
Zinc is one of the better-studied options. In a controlled trial, men with low sperm motility who took 57 mg of zinc twice daily saw significant improvements in sperm quality, count, motility, and fertilizing capacity after three months.
Selenium at 100 mcg per day for three months significantly increased sperm motility in infertile men in a double-blind study, though it didn’t affect sperm count.
L-carnitine at 3 to 4 grams daily for four months helped normalize sperm motility in men with low sperm quality in preliminary research.
That said, a 2024 update to the AUA/ASRM male infertility guidelines noted that the benefits of supplements like antioxidants and vitamins are “of questionable clinical utility” for treating male infertility, and that existing data aren’t strong enough to recommend specific agents. This doesn’t mean these supplements do nothing. It means the evidence is mixed and not yet strong enough for a blanket medical recommendation. For men with known deficiencies or poor semen parameters, targeted supplementation under a doctor’s guidance is reasonable.
Antioxidants: Promising but Uncertain
Oxidative stress damages both eggs and sperm, so antioxidant supplements (vitamin C, vitamin E, selenium, NAC, melatonin) seem like a logical intervention. A Cochrane review of 13 randomized trials involving over 1,200 women found that antioxidant use was associated with live birth rates between 24% and 36%, compared to 19% without them. That’s a meaningful potential increase, but the review rated the evidence as very low quality, meaning the true effect could be smaller or larger than what the studies showed.
The practical takeaway: antioxidants are unlikely to hurt and may help, but they aren’t a guaranteed fix. Taking a prenatal vitamin with a reasonable antioxidant profile, combined with an antioxidant-rich diet, covers this base without requiring a complicated supplement stack.
Diet as a Fertility Tool
Supplements work best on top of a solid dietary foundation, and the Mediterranean diet has the strongest fertility evidence of any eating pattern. A review of clinical studies found that couples with better adherence to the Mediterranean diet were 40% to 100% more likely to achieve clinical pregnancy. Live birth rates were 2.5 times higher in those who followed the diet most closely.
The Mediterranean diet emphasizes vegetables, fruits, whole grains, legumes, nuts, olive oil, and fish, with limited red meat and processed food. It’s naturally rich in many of the same nutrients found in fertility supplements: folate from leafy greens, omega-3s from fish, zinc from nuts and seeds, and antioxidants from colorful produce. If you do nothing else, shifting your eating pattern in this direction is one of the most evidence-backed moves you can make.
When to Start and How Long to Continue
Fertility clinics typically recommend starting a preconception supplement regimen one to three months before trying to conceive. This aligns with the biological timeline: a new egg takes about three months to mature before ovulation, and sperm production takes roughly 74 days. Nutrients you take today won’t affect the egg or sperm available next week, but they will influence the ones maturing over the next cycle.
Continue your prenatal vitamin and folic acid through at least the first 10 weeks of pregnancy. CoQ10 and other targeted supplements are generally used up until conception or a positive pregnancy test, then discussed with your provider. For men, the same three-month lead time applies, since the full sperm production cycle needs that window to reflect any improvements.