Fertility Supplements for Men

How Can Supplements Affect Male Fertility?

Supplements are thought to help mainly by lowering oxidative stress. This is an imbalance in which reactive oxygen species (ROS) - unstable molecules that damage cells - overwhelm the body's defenses and injure sperm.^[2][5]

Some ROS are normal, and even necessary: at low levels they help sperm mature and fertilize an egg. The problem is excess. When ROS climb too high, they damage the sperm cell and fragment its DNA. That damage is linked to lower motility (how well sperm move), lower fertilization and pregnancy outcomes, and miscarriage.^[5]

That damage doesn't show up on a standard semen analysis (spermiogram). It's measured separately, with a sperm DNA fragmentation test that reports the share of sperm carrying damaged DNA. Some laboratories also measure seminal oxidative stress directly - often alongside DNA fragmentation testing - using assays that report the static oxidation-reduction potential. In the MOXI (Males, Antioxidants, and Infertility) trial, a level above 25% counted as high.^[10] But there is no single universal threshold. Cut-offs vary by laboratory and by the assay used.^[21]

How common is oxidative stress? A 2022 Cochrane review estimated it's involved in 25% to 87% of male subfertility cases - a range drawn from studies over the past few decades. Oral antioxidants aim to neutralize that excess and protect sperm quality.^[2]

That's the theory. Whether it leads to more successful pregnancies is a separate question.^[2][4]

Key Insight:
Up to 87% of male subfertility may involve oxidative stress, which is why antioxidant ingredients are so common in fertility supplements.^[1][2]

→ Learn more: Male Infertility

How Long Before Supplements Could Work?

Give it about three months. That's roughly how long the body takes to build a sperm cell. Nothing you start today will change a semen sample next week.^[9]

Sperm production never stops, but each new sperm takes approximately 74 days to develop inside the testicle. Think of it as a 74-day production line: what you change at the start appears at the end about three months later.^[9]

That's why fertility trials test supplements over similar windows. The studies on ashwagandha (3 months), Mucuna pruriens (3 months), and maca (4 months) all used roughly that timeframe before re-checking semen.^[6][7][8] Here's the practical takeaway: start, stay consistent, and reassess after about three months, not three weeks.^[9]

Which Vitamins and Minerals Have the Best Evidence?

A handful of vitamins, minerals, and amino acids have at least some clinical trial evidence for improving sperm parameters. Most of it is modest, and most of it comes from subfertile (reduced fertility) men rather than healthy ones.^[1][2]

A 2020 analysis in Nutrients reviewed the ingredients with trial evidence and identified the minimal effective dose for each - the smallest daily amount shown to improve a sperm measure. The most-studied ingredients are summarized below.^[1]

Source: Garolla et al., Nutrients (2020).^[1]

*Across trials, zinc was given at doses reaching or exceeding the safe upper intake level.^[1]

**The sperm measures listed reflect benefits reported across the doses studied, and were not necessarily all demonstrated at the minimal effective dose.

Zinc

Zinc is the mineral found most often in fertility supplements, and it has trial evidence for improving sperm concentration and morphology (form and structure). It plays a direct role in packaging and protecting sperm DNA. That's why it has been used to improve sperm shape and DNA integrity in men with prostate problems.^[1]

But there's a catch. Every trial showing a zinc benefit used a dose at or above the safe upper limit. In one study, 60 men with poor sperm motility took zinc sulfate at 220 mg twice daily for three months. Their sperm count, motility, and semen volume improved from baseline.^[18] But this was a before-and-after comparison against a fertile reference group, not a placebo-controlled trial. And high zinc intake reduces copper absorption, so more isn't safely better.^[1]

Selenium

Selenium is another mineral with solid evidence, improving sperm concentration and motility, and it's often combined with N-acetyl cysteine. Its benefit appears tied to the mitochondrial sheath, the structure that powers the sperm tail. So, it helps most when that machinery is intact.^[1] In one study of 690 infertile men, selenium plus vitamin E for at least 100 days improved motility, morphology, or both in about 53% of them. Roughly 11% of couples conceived naturally.^[13]

Coenzyme Q10

Coenzyme Q10 (CoQ10) is an antioxidant that supports the energy machinery sperm need to swim. Trials have reported gains in sperm concentration and motility, with motility improving from about 200 mg per day.^[1] In a double-blind trial of men with asthenozoospermia (sperm with low motility), 200 mg daily for six months significantly improved their motility.^[14]

L-Carnitine

L-carnitine helps transport the fuel that sperm burn for movement. Trials have improved sperm count and motility from around 1 g per day, and it works best when the sperm's energy-producing structures are intact.^[1] Pooling the randomized trials, L-carnitine had the largest motility gain of any antioxidant studied.^[15]

Antioxidant Vitamins: C and E

Vitamins C and E are direct antioxidants, and both have improved sperm measures in trials - including DNA integrity. Vitamin C showed benefits for concentration, motility, and DNA integrity from about 0.5 g per day. Vitamin E (as α-tocopherol) helped from as little as 20 mg per day.^[1] In one trial, vitamin C and vitamin E together (1 g of each daily for two months) cut sperm DNA fragmentation in 76% of treated men.^[16] They're also two of the ingredients most likely to be overdone, which matters later.^[3]

Vitamin D

Vitamin D is widely recommended for fertility, but the evidence is humbler than the marketing. Low vitamin D is linked to poorer semen quality. Yet the largest randomized trial, in vitamin D-deficient infertile men, found that supplements didn't improve semen quality. There was a hint of more spontaneous pregnancies in treated couples, but it wasn't statistically significant. In the subgroup of men with low sperm counts (oligozoospermia), vitamin D was linked to a higher live-birth rate than placebo. The sensible move is to check and correct a deficiency, not to take high doses expecting better sperm.^[11]

Folic Acid, Omega-3s, and Others

Several other ingredients have trial evidence for specific sperm measures. Folic acid (from 400 µg per day) has improved sperm count and motility and reduced DNA damage. Omega-3 fatty acids, specifically DHA (docosahexaenoic acid), have improved concentration, motility, and DNA integrity. N-acetyl cysteine, L-arginine, myoinositol, lycopene, and astaxanthin each have at least one supporting trial.^[1]

Bottom Line:
Most of these ingredients can modestly improve sperm measurement, but the dose matters - below the minimal effective dose, there's little reason to expect a benefit.^[1]

What About Herbal Supplements?

A few herbs have real human evidence, several have only mixed or animal data, and many have none at all.^[1][8]

→ Learn more: Supplements for Women

Ashwagandha (Withania somnifera)

Ashwagandha has the most encouraging human data of any fertility herb. In a placebo-controlled pilot trial, men with low sperm counts took 675 mg of root extract daily for 90 days. Their sperm count rose by 167%, semen volume by 53%, and motility by 57% - far more than placebo - with higher testosterone too.^[6]

Mucuna pruriens

Mucuna pruriens (velvet bean) is the other herb with supportive human evidence. In infertile men under psychological stress, three months of treatment improved sperm count and motility. It also lowered markers of oxidative stress and restored the seminal antioxidant defenses.^[7] In one study, 5 g of seed powder daily for three months recovered sperm count and motility, raised testosterone, and lowered prolactin.^[17]

Tribulus terrestris and Maca

Tribulus terrestris has trial evidence for improving sperm count, motility, and morphology (structure and form).^[1] The minimal effective dose is about 250 mg of dry extract, and across the randomized trials daily doses ranged from 250 to 500 mg.^[1][22] Maca, by contrast, is popular but unproven. A 2022 review pooling five randomized trials found its effects on semen quality unclear, with no clear improvement in sperm concentration.^[8]

Herbs With No Evidence

Many popular botanicals - astragalus, damiana, nettle, catuba, and ecklonia - have no clinical evidence of improving sperm parameters at all. And some plant extracts can interfere with how the body processes medications, which is a safety concern, not just a wasted purchase.^[1]

Who Is Most Likely to Benefit?

Supplements are best aimed at a specific group: men with idiopathic infertility (no identifiable cause) who have abnormal sperm parameters. Ideally this follows a proper workup - it isn't for every man trying to conceive.^[1]

The trials behind these ingredients enrolled subfertile men, so the findings don't necessarily apply to a man with a normal semen analysis, who has little to gain.^[2] And the guideline is blunt about the limits: the evidence isn't strong enough to recommend any specific supplement for anyone.^[4]

The strongest studies point one way: test first, correct what's actually low, and be skeptical of mega-blends.^[1][10][11] The trial of a full antioxidant cocktail found no benefit, and vitamin D helps mainly when you're deficient. Targeted supplementation based on test results or a clear deficiency is more sensible than taking a large fertility blend “just in case.”^[1][10][11]

→ Learn more: Varicocele

→ Learn more: Asthenozoospermia, Oligozoospermia, and Teratozoospermia

Do Supplements Actually Improve the Chance of a Baby?

Earlier, the focus was on sperm parameters - count, motility, morphology, and DNA quality. The studies in this section measured something different: pregnancy and live birth. The 2022 Cochrane review pooled the best available trials of antioxidants, taken alone or in combination. It found only low-quality evidence that antioxidants may improve live birth and clinical pregnancy rates for couples at fertility clinics. The trials were small and often poorly reported. The certainty of the evidence ranged from low to very low, and the review called the overall picture inconclusive.^[2]

That's why the 2021 AUA/ASRM guideline - from the American Urological Association and American Society for Reproductive Medicine - is cautious about supplements in general. It calls their benefit of questionable clinical utility, and finds the data too weak to recommend any specific product.^[4]

The most direct test of a blend came in 2020. A large, government-funded randomized trial - the MOXI study, gave 174 men with male-factor infertility a daily antioxidant blend or a placebo. The blend combined seven of the ingredients above: vitamin C, vitamin E, selenium, L-carnitine, zinc, folic acid, and lycopene. After three months, it showed no improvement in sperm parameters or DNA fragmentation. After six months, there was no improvement in pregnancy or live birth, and live births were numerically lower in the supplement group, at 15% versus 24%.^[10]

Key Insight:
The largest randomized trial of a commercial antioxidant blend found it didn't improve sperm quality, DNA integrity, or live birth rates in men with male-factor infertility.^[10]

This can sound discouraging, but the two findings fit together. On their own, and at effective doses, some antioxidants improve specific sperm measures in trials.^[1] Whether that translates into a baby is a separate question.^[2][10]

Can Supplements Harm Your Fertility?

Yes, supplements can backfire, mainly through overdosing, hidden interactions, and the so-called antioxidant paradox.^[1][3]

More isn't better. Large doses of antioxidants like vitamin C, vitamin E, or N-acetyl cysteine can tip the body into reductive stress. Researchers describe this as potentially as harmful as the oxidative stress it's meant to counter.^[3]

Doses and combinations matter. Every trial showing a zinc benefit used a dose at or above the safe upper limit, and high zinc lowers copper absorption. Folic acid can mask a vitamin B12 deficiency, which lets nerve damage progress unnoticed.^[1]

There's also the problem of overloaded products. Many supplements pack in a long list of ingredients. Some contain up to 17, often at doses too low to work, or with no evidence at all.^[1] Because most antioxidants are inexpensive and largely unregulated, quality and dose vary from product to product.^[2] Mild stomach upset is the most commonly reported side effect.^[2]

Important:
More isn't safer. Antioxidant supplements are sold over the counter at high doses, and taking several at once can push intake into a range that may harm sperm rather than help.^[3]

What Else Improves Sperm Quality?

Before reaching for a pill, the strongest lever is often general health - because the same conditions that harm your body harm your sperm.^[1]

Excess weight, metabolic syndrome, heavy alcohol use, cigarette smoking, and environmental pollutants are all strongly linked to lower sperm quality and fertility.^[1] Recreational drugs such as cannabis may also lower semen quality. So does genital heat - from hot tubs, saunas, laptops on the lap, prolonged sitting, and tight underwear.^[12]

Most of these act through the same channels: hormonal disruption and oxidative stress.^[1][12] Reducing them works on the cause, before any pill. Here's the practical takeaway: lose excess weight, stop smoking, and limit alcohol and cannabis.^[1] And keep the scrotum cool - skip the daily sauna and the laptop-on-lap habit.^[12]

Diet is also linked to semen quality. In observational studies, men who follow a healthy dietary pattern tend to have better semen parameters. The foods tied to better quality are fish and seafood, poultry, cereals, vegetables, and fruit. Diets high in processed meat, full-fat dairy, coffee, alcohol, sugar-sweetened beverages, and sweets are tied to poorer quality. Because the evidence is observational, it shows association, not proven cause.^[20]

→ Learn more: Fertility and Age

So, What Should You Do Now?

If you're considering supplements as part of trying to conceive, here's a sensible order of operations.

Step 1: Get a Semen Analysis

Start with a semen analysis so you know which sperm parameters, if any, need attention.^[1][2] If a result is abnormal, repeat the test within 2 to 3 weeks - or after about three months if you are checking the effect of a lifestyle change.^[19]

Step 2: Fix the Big Things First

Address weight, smoking, alcohol, cannabis, and heat exposure before spending on supplements - these work on the cause of oxidative stress.^[1][12]

Step 3: Correct Deficiencies, Don't Mega-Blend

Favor ingredients with trial evidence at their effective dose, and correct documented deficiencies, rather than taking a large cocktail or mega-doses.^[1][10]

Step 4: Give It About Three Months, Then Reassess

Because sperm take approximately 74 days to form, repeat the semen analysis after about three months rather than judging results early.^[9]

Step 5: Avoid Overloaded, Mega-Dosed Products

Skip products crammed with many ingredients at token doses, and don't stack several antioxidant products at once.^[1][3]

Step 6: Talk to a Specialist and Compare Clinics

Discuss your results with a urologist or fertility specialist, and compare clinics before committing to treatment.^[4]

→ Compare fertility clinics worldwide: MedicalNavigator.com/clinics/reproductive-medicine

Too Long, Didn't Read

• Oxidative stress is involved in an estimated up to 87% of male subfertility, damaging sperm and fragmenting DNA.
• Sperm takes approximately 74 days to form, so reassess any supplement after about three months.
• Evidence that supplements lead to a live birth is weak, and the largest randomized trial found no benefit.
• Vitamin D is worth correcting if it's low, but supplements haven't been shown to improve semen quality.
• Zinc and selenium have the most mineral evidence, but zinc trials used doses at or above the safe upper limit.
• Among herbs, ashwagandha and Mucuna pruriens show the most promise, while maca's evidence is mixed.
• More isn't better - overdosing antioxidants can cause reductive stress and harm sperm.

References

1. Garolla A, Petre GC, Francini-Pesenti F, De Toni L, Vitagliano A, Di Nisio A, Foresta C. Dietary Supplements for Male Infertility: A Critical Evaluation of Their Composition. Nutrients. 2020;12(5):1472. ↩
2. de Ligny W, Smits RM, Mackenzie-Proctor R, Jordan V, Fleischer K, de Bruin JP, Showell MG. Antioxidants for male subfertility. Cochrane Database Syst Rev. 2022;5:CD007411. ↩
3. Henkel R, Sandhu IS, Agarwal A. The excessive use of antioxidant therapy: A possible cause of male infertility? Andrologia. 2019;51(1):e13162. ↩
4. Schlegel PN, Sigman M, Collura B, et al. Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline Part II. Fertil Steril. 2021;115(1):62–69. ↩
5. Alahmar AT. Role of Oxidative Stress in Male Infertility: An Updated Review. J Hum Reprod Sci. 2019;12(1):4–18. ↩
6. Ambiye VR, Langade D, Dongre S, Aptikar P, Kulkarni M, Dongre A. Clinical Evaluation of the Spermatogenic Activity of the Root Extract of Ashwagandha (Withania somnifera) in Oligospermic Males: A Pilot Study. Evid Based Complement Alternat Med. 2013;2013:571420. ↩
7. Shukla KK, Mahdi AA, Ahmad MK, Jaiswar SP, Shankwar SN, Tiwari SC. Mucuna pruriens Reduces Stress and Improves the Quality of Semen in Infertile Men. Evid Based Complement Alternat Med. 2010;7(1):137–144. ↩
8. Lee HW, Lee MS, Qu F, Lee JW, Kim E. Maca (Lepidium meyenii Walp.) on Semen Quality Parameters: A Systematic Review and Meta-Analysis. Front Pharmacol. 2022;13:934740. ↩
9. Amann RP. The cycle of the seminiferous epithelium in humans: a need to revisit? J Androl. 2008;29(5):469–487. ↩
10. Steiner AZ, Hansen KR, Barnhart KT, et al. The Effect of Antioxidants on Male Factor Infertility: The Males, Antioxidants, and Infertility (MOXI) Randomized Clinical Trial. Fertil Steril. 2020;113(3):552–560. ↩
11. Blomberg Jensen M, Lawaetz JG, Petersen JH, Juul A, Jørgensen N. Effects of Vitamin D Supplementation on Semen Quality, Reproductive Hormones, and Live Birth Rate: A Randomized Clinical Trial. J Clin Endocrinol Metab. 2018;103(3):870–881. ↩
12. Leisegang K, Dutta S. Do lifestyle practices impede male fertility? Andrologia. 2021;53(1):e13595. ↩
13. Moslemi MK, Tavanbakhsh S. Selenium–vitamin E supplementation in infertile men: effects on semen parameters and pregnancy rate. Int J Gen Med. 2011;4:99–104. ↩
14. Balercia G, Buldreghini E, Vignini A, et al. Coenzyme Q10 treatment in infertile men with idiopathic asthenozoospermia: a placebo-controlled, double-blind randomized trial. Fertil Steril. 2009;91(5):1785–1792. ↩
15. Su L, Qu H, Cao Y, Zhu J, Zhang SZ, Wu J, Jiao YZ. Effect of Antioxidants on Sperm Quality Parameters in Subfertile Men: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials. Adv Nutr. 2022;13(2):586–594. ↩
16. Greco E, Romano S, Iacobelli M, Ferrero S, Baroni E, Minasi MG, Ubaldi F, Rienzi L, Tesarik J. ICSI in cases of sperm DNA damage: beneficial effect of oral antioxidant treatment. Hum Reprod. 2005;20(9):2590–2594. ↩
17. Shukla KK, Mahdi AA, Ahmad MK, Shankhwar SN, Rajender S, Jaiswar SP. Mucuna pruriens improves male fertility by its action on the hypothalamus–pituitary–gonadal axis. Fertil Steril. 2009;92(6):1934–1940. ↩
18. Alsalman ARS, Almashhedy LA, Alta'ee AH, Hadwan MH. Effect of Zinc Supplementation on Urate Pathway Enzymes in Spermatozoa and Seminal Plasma of Iraqi Asthenozoospermic Patients: A Randomized Controlled Trial. Int J Fertil Steril. 2020;13(4):315–323. ↩
19. World Health Organization. WHO Laboratory Manual for the Examination and Processing of Human Semen. 6th ed. Geneva: World Health Organization; 2021. ↩
20. Salas-Huetos A, Bulló M, Salas-Salvadó J. Dietary patterns, foods and nutrients in male fertility parameters and fecundability: a systematic review of observational studies. Hum Reprod Update. 2017;23(4):371–389. ↩
21. Esteves SC, Zini A, Coward RM, et al. Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations. Andrologia. 2021;53(2):e13874. ↩
22. Sanagoo S, Sadeghzadeh Oskouei B, Gassab Abdollahi N, Salehi-Pourmehr H, Hazhir N, Farshbaf-Khalili A. Effect of Tribulus terrestris L. on sperm parameters in men with idiopathic infertility: A systematic review. Complement Ther Med. 2019;42:95–103. ↩