A 2026 expert consensus from the Global Andrology Forum reviews how antioxidants are used in male infertility, showing which practices are supported by expert agreement and where evidence is still lacking.
Antioxidants are widely used, but research results have been inconsistent, with studies differing in who was studied, which supplements were used, how long they were taken, and which outcomes were measured. Because of this, major organizations like the EAU and AUA/ASRM have been cautious about recommending them.
The Global Andrology Forum (GAF) developed guidelines on the use of antioxidants for male infertility. They used an expert consensus process, with 151 clinicians voting on proposed guidelines and 84 senior experts rating each as a strong or weak based on the evidence and risk–benefit balance.
High-quality randomized trials and standardized testing methods are still lacking, and these guidelines could change as stronger evidence emerges.
🔗 Original studies are referenced in this post or within the linked Remembryo posts.
💡 Reminder: Terms underlined with a dotted black line are linked to glossary entries. Clicking these does not count toward your paywall limit.
GAF’s strongly recommended guidelines
These guidelines were “strongly” rated, meaning that at least 80% of experts rated the guideline as strong.
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A full male infertility workup should be done before starting antioxidant supplements (100%)
- Evidence: Strong agreement across international guidelines and expert panels that supplements should not replace proper testing for hormonal, structural, genetic, infectious, or lifestyle-related causes.
- Evidence: Strong agreement across international guidelines and expert panels that supplements should not replace proper testing for hormonal, structural, genetic, infectious, or lifestyle-related causes.
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Lifestyle changes may improve sperm quality (97%)
- Evidence: Lifestyle changes including smoking cessation, weight loss, and increased physical activity are associated with improved sperm parameters, although high-quality data are limited.
- Evidence: Lifestyle changes including smoking cessation, weight loss, and increased physical activity are associated with improved sperm parameters, although high-quality data are limited.
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Antioxidant treatment should be about 3–6 months (94%)
- Evidence: Sperm take 2-3 months to develop, and when improvements are seen, they usually happen within 3-6 months.
- Evidence: Sperm take 2-3 months to develop, and when improvements are seen, they usually happen within 3-6 months.
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Sperm DNA fragmentation and oxidative stress testing may help identify underlying issues (89%)
- Evidence: The review notes that higher sperm DNA fragmentation and oxidative stress are associated with poorer fertility outcomes, and that assessing these factors may help identify underlying causes and allow more targeted management. At the same time, the authors acknowledge that testing methods vary, randomized trials are lacking, and clinical benefit isn’t clear.
- Evidence: The review notes that higher sperm DNA fragmentation and oxidative stress are associated with poorer fertility outcomes, and that assessing these factors may help identify underlying causes and allow more targeted management. At the same time, the authors acknowledge that testing methods vary, randomized trials are lacking, and clinical benefit isn’t clear.
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Antioxidants may improve outcomes for both natural and ART pregnancies, but additional randomized trials are still needed (82%)
- Evidence: Meta-analyses suggest antioxidants may improve pregnancy or live birth rates, but evidence is low quality and based on small trials. Large randomized trials found no benefit on semen parameters, DNA integrity, or live birth, and professional guidelines note that clinical benefit remains uncertain and data are insufficient to recommend specific supplements.
- Evidence: Meta-analyses suggest antioxidants may improve pregnancy or live birth rates, but evidence is low quality and based on small trials. Large randomized trials found no benefit on semen parameters, DNA integrity, or live birth, and professional guidelines note that clinical benefit remains uncertain and data are insufficient to recommend specific supplements.
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Antioxidants are not expected to restore sperm production in non-obstructive azoospermia patients (82%)
- Evidence: Studies are small and inconsistent, and there is no reliable evidence that antioxidants restore sperm in the ejaculate.
GAF’s weakly recommended guidelines
These guidelines were “weakly” rated, meaning that <80% of experts rated the guideline as strong.
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Consider antioxidants for men with oxidative stress risk factors (79%)
- Evidence: Conditions such as varicocele, infection, obesity, smoking, and advanced paternal age are linked to higher oxidative stress. Evidence that antioxidants improve fertility outcomes in these groups is limited and inconsistent, and guidelines note uncertain clinical benefit and lack of data on optimal use.
- Evidence: Conditions such as varicocele, infection, obesity, smoking, and advanced paternal age are linked to higher oxidative stress. Evidence that antioxidants improve fertility outcomes in these groups is limited and inconsistent, and guidelines note uncertain clinical benefit and lack of data on optimal use.
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Antioxidants may be considered for isolated high sperm DNA fragmentation with otherwise normal semen parameters (79%)
- Evidence: Evidence on antioxidant therapy in male infertility is mixed, with modest improvements in sperm DNA fragmentation and semen quality but limited and uncertain clinical relevance, and no standardized treatment regimens.
- Evidence: Evidence on antioxidant therapy in male infertility is mixed, with modest improvements in sperm DNA fragmentation and semen quality but limited and uncertain clinical relevance, and no standardized treatment regimens.
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Antioxidants may improve semen parameters and oxidative stress markers (78%)
- Evidence: Meta-analyses and randomized trials show that antioxidants can improve sperm concentration, motility, morphology, oxidative stress levels, and sperm DNA fragmentation, but some studies show no benefit.
- Evidence: Meta-analyses and randomized trials show that antioxidants can improve sperm concentration, motility, morphology, oxidative stress levels, and sperm DNA fragmentation, but some studies show no benefit.
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Combining different antioxidants is biologically plausible but unproven compared to using a single one (70%)
- Evidence: No strong trials directly compare single antioxidants with combination products, and existing results are inconsistent.
- Evidence: No strong trials directly compare single antioxidants with combination products, and existing results are inconsistent.
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Antioxidants appear safe short term, but continuing beyond 3–6 months without evidence of oxidative stress is discouraged (70%)
- Evidence: Evidence on antioxidant duration is mixed, with small improvements seen after about 3 months and uncertain clinical benefit.
- Evidence: Evidence on antioxidant duration is mixed, with small improvements seen after about 3 months and uncertain clinical benefit.
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Antioxidants may be considered in unexplained or idiopathic male infertility (64%)
- Evidence: Reviews show small improvements in semen measures, but randomized trials show mixed or no effects on pregnancy or live birth.
Want to read more about supplement use and sperm quality?
Researchers in a 2023 study evaluated 34 common male fertility sperm supplement brands for safety and efficacy. They found that the majority exceeded the recommended daily allowance, with two that exceeded the tolerable upper intake level. Less than half had supporting studies for their use, with the overall quality of evidence being ranked as poor. Read more.
Researchers in a 2022 study performed a systematic review and meta-analysis on infertile men who used antioxidant supplements, and found a benefit in pregnancy and semen parameter outcomes. Read more.
A 2025 review found that sperm DNA fragmentation testing provides useful insight into male infertility and may help in select cases, but inconsistent evidence, lack of test standardization, and variable results limit its routine use in fertility care. Read more.
While multiple studies have shown the benefit of antioxidant supplements in improving male fertility, what effect excessive supplementation has isn't clear. This post combines a new study with older studies that show high levels of supplements can harm male fertility. However, these studies all have their limitations, and better quality research is needed to draw conclusions. Read more.
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About Embryoman
Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.