JAMA Netw Open

Are antioxidant supplements effective for men facing fertility challenges?

September 29, 2025

Antioxidant supplements didn't lead to higher ongoing pregnancy rates compared with placebo, leading researchers to conclude they shouldn't be recommended for men undergoing fertility treatment.

Study details: The multicenter, randomized, double-blind, placebo-controlled SUMMER trial (NCT03337360) was conducted across 21 fertility centers in the Netherlands. It enrolled 1,171 men (median age, 34 years) with female partners (median age, 32 years) undergoing fertility care. Participants were randomized to receive either a daily antioxidant supplement (Impryl) or placebo for 6 months. Primary outcome: ongoing pregnancy within 6 months; secondary outcomes: semen parameters, sperm DNA fragmentation, and IVF/ICSI metrics.

Results: Ongoing pregnancy rates weren’t significantly different between the antioxidant and placebo groups (33.8% vs. 37.5%; adjusted odds ratio [AOR], 0.85; P=.20). Notably, during the 4 to 6 month “optimal effect” window, the antioxidant group had significantly lower pregnancy rates (15.5% vs. 21.5%; AOR, 0.66; P = .02). No significant improvements were observed in semen quality or other secondary outcomes.

Source:

de Ligny WR, et al. (2025, September 2). JAMA Netw Open. Antioxidant Treatment and the Chance to Conceive in Men Seeking Fertility Care: The SUMMER Randomized Clinical Trial. https://pubmed.ncbi.nlm.nih.gov/40996763/