Male Fertility Supplements That Actually Have Evidence Behind Them

Walk into any pharmacy's "men's fertility" section and you'll find a wall of supplements promising bigger, faster, stronger sperm. Some of that is backed by real trial data. A lot of it is marketing wearing a lab coat. Here's what the actual research says about the ingredients that show up most often -- and where the honest limits of that research are.

The big honest caveat, up front

Almost all of the research on male fertility supplements measures semen parameters -- sperm concentration, motility (how well they swim), and morphology (how normally they're shaped) -- not whether a couple actually gets pregnant. Those two things are related but not the same. A 2022 Cochrane review pooling 90 trials and over 10,000 subfertile men found that antioxidant supplementation may increase live birth rates (odds ratio 1.43), but rated the certainty of that evidence as very low, mainly because most trials were small, short, and didn't consistently report on pregnancy or live birth at all. So: promising direction, not a slam dunk. Keep that in mind for everything below.

CoQ10

Coenzyme Q10 is one of the better-studied options, and the evidence is genuinely encouraging for sperm quality specifically. A network meta-analysis of antioxidant trials found CoQ10 produced the largest increase in sperm concentration of any antioxidant tested, and other reviews consistently link it to improved motility, likely because CoQ10 plays a direct role in the mitochondrial energy production that powers sperm movement. Studied doses typically run 200-600mg per day for at least 90 days -- shorter than that and you likely won't see an effect, since a full cycle of sperm development takes about 74 days.

L-carnitine

L-carnitine trials consistently show improvements in sperm motility, and in some head-to-head comparisons it's outperformed CoQ10 and vitamin E specifically on that measure. One randomized controlled trial found L-carnitine improved motility, morphology, and concentration, plus modestly raised testosterone and LH -- benefits the CoQ10/vitamin E comparison group didn't fully match. If motility specifically is your concern (a low progressive-motility number on a semen analysis), this is one of the better-evidenced options.

Zinc and selenium

Zinc is one of the most concentrated minerals in seminal plasma and is directly involved in sperm development and DNA integrity; deficiency is linked to lower sperm count and poor motility. A large systematic review and meta-analysis of RCTs found both zinc and selenium supplementation improved sperm motility and morphology, with zinc showing a meaningfully larger effect on motility than selenium alone. These are cheap, well-tolerated, and reasonable to combine with the above.

Omega-3 fatty acids

The same large meta-analysis found omega-3 supplementation improved total sperm count, concentration, motility, and morphology -- a broader spread of benefit than most single ingredients on this list. If you're not already eating fatty fish regularly, a fish oil supplement is a reasonably well-supported add.

Ashwagandha

Less studied than the above, but the existing data is interesting: a 90-day pilot study found ashwagandha root extract improved sperm concentration, motility, and volume compared to placebo, alongside lower stress markers and improved testosterone. The proposed mechanism is that it reduces cortisol interference with testosterone production. Promising, but it's resting on far fewer and smaller trials than CoQ10 or zinc, so treat it as a "worth trying" rather than a "proven" pick.

What has weak or inconsistent evidence

Maca root has a few small studies showing minor self-reported libido improvements, but no consistent evidence it meaningfully changes semen parameters. Folic acid taken alone (without zinc or other antioxidants alongside it) has similarly mixed results in male-specific trials, even though it's well-established for female preconception health. If a product's entire pitch is maca or solo folic acid, temper your expectations.

The bottom line

If you're going to try a supplement approach, CoQ10, L-carnitine, zinc, and omega-3s have the most consistent trial support behind them, and combining a few is common in the actual research (several trials test combination formulas rather than single ingredients). Give it a full 90 days before judging results, since that's roughly how long sperm production takes to turn over. And keep expectations calibrated: this can meaningfully improve semen parameters for a lot of men, but it is not a guaranteed fix, and it doesn't replace an actual semen analysis or a doctor's evaluation if you've been trying for a while without success. See our recommendations page for specific products we'd point you toward.

References

1. de Ligny, W., et al. (2022). Antioxidants for male subfertility. Cochrane Database of Systematic Reviews.
2. Systematic review and network meta-analysis. (2025). Effects of Carnitine and Coenzyme Q10 on Sperm Quality and Pregnancy Rates in Men with Unexplained Infertility.
3. Systematic review and meta-analysis. (2026). The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters. Andrology.
4. Pilot study. (2013). Ashwagandha root extract and semen parameters. American Journal of Men's Health.