Key takeaways:
- The most comprehensive analysis of male fertility supplements to date, a 2025 meta-analysis of 50 randomized trials with more than 4,800 men, found no effect of any dietary supplement on pregnancy or live birth, while finding improvements in individual sperm measures for some supplements, including selenium, carnitine, and coenzyme Q10 for motility (Michaelsen et al., Nutrients, 2025).
- The largest single trial, the FAZST study of 2,370 couples, found that folic acid and zinc taken by the male partner did not improve semen quality or live birth, and DNA fragmentation was slightly higher in the supplement group, 29.7% versus 27.2% (Schisterman et al., JAMA, 2020).
- SwimScore's position is that supplements are a "maybe, after testing" decision rather than a first step: measure your semen parameters, DNA Fragmentation Index (DFI), and hormones first, give any change at least 12 weeks, then retest to see whether your own numbers moved.
By SwimScore. Medically reviewed by [reviewer name and credentials to be added before publishing]. Last updated October 27, 2026.
Search for ways to improve sperm and you will find a wall of supplement ads, each citing a study. Some of those studies are real and well run. Others are tiny, funded by the company selling the product, or measure something that never makes it onto a baby's birth certificate. The result is that a man trying to decide whether to spend money on a bottle of capsules has almost no way to tell what is solid and what is marketing.
This is the one place where we pull the evidence for every common supplement together: coenzyme Q10, L-carnitine, omega-3s, zinc and folate, selenium, alpha-lipoic acid, and ashwagandha. We go through what each one has been shown to do to concentration, motility, morphology, and DNA fragmentation, and then take on the harder question of whether any of it helps a couple actually conceive. Our other articles go deeper on motility, concentration, and morphology. This page ties them together.
Do Male Fertility Supplements Actually Help You Conceive?
Not in any way that has been proven. A 2025 systematic review and meta-analysis pooled 50 randomized controlled trials of dietary supplements in men with more than 4,800 participants, and it found no effect on pregnancy or live birth (Michaelsen et al., Nutrients, 2025). A randomized controlled trial is a study where men are assigned by chance to a supplement or a dummy pill, which is the fairest way to test whether something works. A meta-analysis combines many such trials into one larger answer.
That headline needs two pieces of context. First, the same analysis did find that some supplements improved individual sperm measures, which we cover below. Second, the evidence for pregnancy is thin, not zero. The authors rated the certainty of the evidence as mostly low or very low, because many trials were small, used different doses and different types of patients, and had a risk of bias (Michaelsen et al., Nutrients, 2025). So the honest reading is not "supplements do not work." It is "nobody has shown, with trials strong enough to trust, that they lead to more babies."
A separate Cochrane review, which is the gold standard for pooling medical trials, looked only at antioxidants. Antioxidants are compounds that neutralize oxidative stress, a kind of chemical wear and tear that can damage sperm. It covered 90 studies and 10,303 subfertile men. Antioxidants were linked to more live births (odds ratio 1.43, from 12 trials and 1,283 men), but the certainty was very low, and when the trials at high risk of bias were removed the benefit was no longer clear (de Ligny et al., Cochrane Database of Systematic Reviews, 2022). The same review found more mild stomach upset with antioxidants and no clear increase in miscarriage. Taken together, the two reviews point the same direction: possible signal, not proof.
Which Supplements Improve Sperm Motility?
Sperm motility is the share of sperm that are moving, and progressive motility is the share swimming forward in a purposeful way. The WHO 6th Edition sets the progressive motility threshold at 32%. Motility is where the supplement evidence is most consistent.
In the 2025 meta-analysis, selenium raised total motility by about 15 percentage points in two small trials, L-carnitine raised it by about 10 points across three to four trials, and coenzyme Q10 (CoQ10) raised total motility by about 4 points and progressive motility by about 5 points in two trials (Michaelsen et al., Nutrients, 2025). CoQ10 is a compound your cells use to make energy, and sperm need a great deal of energy to swim. An earlier 2018 meta-analysis of 15 trials found that carnitines were the only supplement to raise progressive motility, by about 7.45 percentage points (Salas-Huetos et al., Advances in Nutrition, 2018). Carnitine helps carry fat into the cell's power plants, which is why it is studied for sperm tails.
Notice how small these trial counts are. Two trials is a start, not a body of proof, and the confidence intervals around some of these results, the range in which the true effect probably falls, are wide.
Which Supplements Improve Sperm Concentration?
Sperm concentration is how many sperm are in each milliliter of semen. The WHO 6th Edition threshold is 16 million per milliliter. The picture here is more mixed than most supplement pages admit.
The 2025 meta-analysis found improved concentration with zinc plus folic acid (about 7.8 million per milliliter across six trials) and with combination products containing three or more ingredients (about 10.5 million per milliliter across eight to ten trials). It found no concentration effect for CoQ10, carnitine, selenium, vitamin D, vitamin E, or omega-3s (Michaelsen et al., Nutrients, 2025). The authors also flagged signs of publication bias in the combination-product result, which means small trials with disappointing results may simply never have been published.
The earlier 2018 meta-analysis reported the opposite for omega-3s, with the largest concentration gain of any supplement, about 11 million per milliliter (Salas-Huetos et al., Advances in Nutrition, 2018). Two good meta-analyses disagreeing is a sign of how fragile this field is. The newer one included more trials and more recent ones, but neither can settle it.
Then there is the single biggest test. The FAZST trial randomly assigned 2,370 men whose couples were planning fertility treatment to take 5 mg of folic acid and 30 mg of zinc daily or a placebo for six months. Sperm concentration, motility, morphology, and total motile sperm count were not significantly different, and live birth was 34% in the supplement group versus 35% in the placebo group (Schisterman et al., JAMA, 2020). A well-powered, carefully run trial finding nothing is a good reason to doubt the smaller positive trials.
Which Supplements Improve Sperm Morphology?
Sperm morphology is the share of sperm with a normal shape. The Kruger strict criteria threshold is 4%. The 2025 meta-analysis found only one supplement that improved normal morphology: alpha-lipoic acid, an antioxidant the body makes in small amounts, raised it by under one percentage point in two trials (Michaelsen et al., Nutrients, 2025). The 2018 meta-analysis reported small gains for selenium, omega-3s, and CoQ10, and a larger one for carnitines (Salas-Huetos et al., Advances in Nutrition, 2018). A change of one percentage point on a measure where 4% is the cutoff is real on paper, but it is hard to know whether it matters to any individual man. Morphology is also the hardest sperm measure to score consistently, so small shifts can be partly lab noise.
Do Supplements Lower Sperm DNA Fragmentation?
Sperm DNA fragmentation is the share of sperm carrying broken DNA, reported as the DNA Fragmentation Index (DFI). Below 15% is good, 15% to 30% is moderate, and above 30% is high. We could not find a clean, reliable pooled benefit from supplements here. In the 2025 meta-analysis, combination supplements showed no effect on DFI (Michaelsen et al., Nutrients, 2025). In FAZST, DFI was slightly higher in the folic acid and zinc group, 29.7% versus 27.2% (Schisterman et al., JAMA, 2020).
For DFI, the cause matters more than the capsule. A varicocele, an enlarged vein in the scrotum, is one of the best-documented fixable causes, which we cover in our varicocele article. Our guide to what causes high DNA fragmentation walks through the rest.
What About Ashwagandha?
Ashwagandha is an herb used in traditional Indian medicine. Its fertility evidence comes from small trials, and the most cited is a pilot study of 46 men with low sperm counts (5 to 20 million per milliliter) who took a branded root extract or a placebo for 90 days. Sperm concentration in the ashwagandha group rose from about 9.6 to 25.6 million per milliliter, versus 10.2 to 13.2 in the placebo group (Ambiye et al., Evidence-Based Complementary and Alternative Medicine, 2013). That sounds dramatic, but the authors themselves called it an exploratory pilot, the sample was small, they analyzed only the men who completed the protocol, the reported statistics were inconsistent between the abstract and the figures, and the extract came from a named manufacturer. We did not find a pooled analysis of ashwagandha and semen quality, so we treat it as an interesting lead that has not yet been confirmed.
What We Are More Skeptical About
We are most skeptical of any product that cites a motility or concentration improvement as if it were a pregnancy result. Improving a lab number and producing a baby are different outcomes, and the second depends on the female partner's health, timing, age, and plain luck. We are skeptical of combination products with long ingredient lists, because they cannot tell you which ingredient did what, and the one meta-analysis result for them carries a publication bias warning. We are skeptical of very high doses: the authors of the 2025 meta-analysis noted that some trials used doses above the recommended tolerable upper intake levels, particularly for zinc, folic acid, and vitamin D (Michaelsen et al., Nutrients, 2025).
We are also skeptical of the idea that more is better. FAZST is the clearest warning: a supplement that sounds sensible and has some smaller trials behind it did not help in the largest trial, and its DFI number moved the wrong way. And we are skeptical of the opposite headline, the one that says supplements are all useless. The motility signal for carnitine, CoQ10, and selenium shows up in more than one analysis, even if the certainty is low.
How Should You Think About Supplements Practically?
Start with your numbers, not a product. A semen analysis with DNA fragmentation, plus a hormone panel, shows whether your issue is motility, concentration, shape, DNA damage, or a hormone problem that no capsule will fix. Low testosterone with high LH, a varicocele, or testosterone therapy suppressing your sperm production are all common causes that supplements do not address. If you are currently on testosterone therapy, that matters far more than any supplement; see our article on TRT and fertility.
If your results show a motility problem and you and a clinician decide a supplement is worth trying, the evidence best supports motility as the target, and there are two practical rules. Sperm take roughly 72 days to develop, so any change needs at least 12 weeks before a retest can show it. And the retest has to come from the same lab and method, so you are comparing like with like. If the numbers did not move, you have learned something and saved money. If they did, you still do not know it will change pregnancy odds, but you have a better-informed picture. Supplements are not self-managed medicine, and this is the kind of decision to make with a urologist or fertility specialist, especially if you take other medication.
Our Take
What we know: some supplements, especially carnitine, CoQ10, and selenium, improve sperm motility in small trials, and several analyses agree on the direction. What we do not know: whether those lab improvements lead to more pregnancies or live births, because no pooled trial evidence has shown that, and the largest trial of a popular combination found nothing.
Why it can still be worth knowing your numbers: a supplement is a low-cost experiment only if you can measure the result. Without a baseline and a retest, you are guessing. SwimScore Complete measures concentration, progressive motility, total motility, morphology, DNA fragmentation, and a hormone panel through a CLIA-certified lab, assessed against WHO 6th Edition thresholds, so you can see exactly what you are trying to change and whether it changed. Know your numbers. Target what the evidence supports. Give it at least 12 weeks. Measure again.
FAQ
Do supplements improve male fertility?
Some supplements improve individual sperm measures, but a 2025 meta-analysis of 50 randomized trials with more than 4,800 men found no effect on pregnancy or live birth (Michaelsen et al., Nutrients, 2025).
Does CoQ10 help sperm?
In the 2025 meta-analysis, CoQ10 improved total motility and progressive motility in two trials but showed no effect on concentration (Michaelsen et al., Nutrients, 2025).
Do zinc and folic acid improve sperm count?
Results conflict. A meta-analysis found higher concentration with zinc plus folic acid, but the 2,370-couple FAZST trial found no improvement in semen quality or live birth (Michaelsen et al., Nutrients, 2025; Schisterman et al., JAMA, 2020).
How long do supplements take to work on sperm?
Sperm take roughly 72 days to develop, so SwimScore recommends waiting at least 12 weeks before retesting.
Should I test before taking a fertility supplement?
Yes. A baseline semen analysis, DNA Fragmentation Index, and hormone panel show which problem you actually have and let you measure whether anything changed.
References
- Michaelsen MP, Poulsen M, Bjerregaard AA, et al. The Effect of Dietary Supplements on Male Infertility in Terms of Pregnancy, Live Birth, and Sperm Parameters: A Systematic Review and Meta-Analysis. Nutrients. 2025;17(10):1710. https://doi.org/10.3390/nu17101710
- de Ligny W, Smits RM, Mackenzie-Proctor R, et al. Antioxidants for male subfertility. Cochrane Database of Systematic Reviews. 2022;5:CD007411. https://doi.org/10.1002/14651858.CD007411.pub5
- Schisterman EF, Sjaarda LA, Clemons T, et al. Effect of Folic Acid and Zinc Supplementation in Men on Semen Quality and Live Birth Among Couples Undergoing Infertility Treatment: A Randomized Clinical Trial. JAMA. 2020;323(1):35-48. https://doi.org/10.1001/jama.2019.18714
- Salas-Huetos A, Rosique-Esteban N, Becerra-Tomas N, Vizmanos B, Bullo M, Salas-Salvado J. The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Advances in Nutrition. 2018;9(6):833-848. https://doi.org/10.1093/advances/nmy057
- 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. Evidence-Based Complementary and Alternative Medicine. 2013;2013:571420. https://doi.org/10.1155/2013/571420
Want to know which of your numbers, if any, a change could actually move? SwimScore Complete measures semen parameters, DNA fragmentation, and hormones together, so you can compare before and after on the same method.
Fertility clinics: if patients arrive asking about supplements, see how SwimScore can give them a standardized baseline on our clinic page.
This article is for general education and is not medical advice. Decisions about supplements, especially alongside other medication, should be made with a urologist or fertility specialist.
SwimScore uses CLIA-certified labs for all semen analysis and hormone testing, assessed against WHO 6th Edition clinical thresholds.
