Acne Drug Isotretinoin Stimulates Sperm Production in Small Study of Severely Infertile Men

A decades-old acne medication, isotretinoin, produced measurable sperm in the ejaculate of a subset of men with severe infertility in a small clinical study, offering a potential noninvasive alternative to surgical sperm retrieval.

Researchers enrolled 30 men — 26 with azoospermia (no sperm in the ejaculate) and four with cryptozoospermia (very few sperm) — and treated them with 20 milligrams of isotretinoin twice daily for six months. Ninety percent of the participants had previously undergone unsuccessful testicular sperm retrieval procedures. By the end of treatment, 11 men began producing motile sperm in their ejaculate: all four with cryptozoospermia and seven with azoospermia. Among those who produced sperm, 82% saw sperm appear within three months of starting therapy.

The newly produced sperm were used in assisted reproduction. Men who underwent in vitro fertilization (IVF) with sperm collected after isotretinoin treatment produced healthy embryos and multiple pregnancies, with at least one live birth reported in the study. For participants who still required surgical sperm retrieval after drug therapy, the procedures were shorter on average — 63 minutes compared with 105 minutes for prior attempts — investigators reported.

Isotretinoin is a potent derivative of vitamin A that mimics retinoic acid, a molecule essential for the process of sperm development. Previous research has found that some infertile men lack adequate retinoic acid in their testes; investigators hypothesized that isotretinoin could substitute for that deficiency and trigger spermatogenesis. "For some men, many of whom have no options for treatment, this could be a game changer," said Dr. Stephanie Page, a professor of medicine at the University of Washington, who was not involved in the research.

Side effects were consistent with those known for isotretinoin. All participants experienced dry skin and chapped lips; four developed rashes, 14 reported irritability, and five had changes in cholesterol or triglyceride levels. No participants discontinued the regimen because of side effects. The drug is known to cause severe birth defects when taken by pregnant women, but experts note the risks differ in men. "This new research suggests it may have a paradoxical benefit by enhancing sperm production in certain men," said Dr. Justin Houman, a urologist not involved in the study, while cautioning that the findings are preliminary.

Male infertility affects a substantial portion of the population; studies estimate up to 15% of U.S. men experience fertility issues. For men with cryptozoospermia or azoospermia, options have been limited. Surgical extraction of sperm from the testes has been the primary route to biological fatherhood, but success rates vary and the procedures carry risks including pain, bleeding, infection and rare long-term damage. The Cleveland Clinic reports success rates of roughly 40% to 60% for testicular sperm retrieval.

Investigators and outside experts emphasized the study’s small size and nonrandomized design. "This requires replication in larger, randomized trials before we can consider it a true breakthrough," Houman said. The drug has not been approved by the U.S. Food and Drug Administration for treatment of male infertility.

Lead clinicians have said they hope future work will identify which men are most likely to benefit and whether isotretinoin can improve sperm quality and long-term fertility outcomes. Meanwhile, clinicians at the Turek Clinic have begun offering a six-month isotretinoin-based program under clinical oversight to qualified patients seeking alternatives to surgical retrieval.

The results point to a potential new approach for a subset of infertile men, but researchers and clinicians urged caution until larger, controlled trials confirm safety and efficacy and clarify which patients are likely to respond.