Impact of GLP-1 Receptor Agonists on Male Fertility: Emerging Evidence and Future Directions

Ozempic-class drugs may help sperm in obese men, but most of the evidence so far is from rats

Journal: Urology | Published: 2025-09-26 | Type: Journal Article, Review | PMID: 41016449 Authors: Kuchakulla M, Poppas PJ, Wald G, Masterson JM, Gurayah AA, Bhambhvani HP, Kashanian JA (New York-Presbyterian Hospital / Weill Cornell Medical Center, New York, NY; Eastern Virginia Medical School) Funding/COI: No funding source listed. Senior author James Kashanian is a paid consultant for Endo Pharmaceuticals; the remaining six authors report no conflicts.

Summary

This is a narrative review of GLP-1 receptor agonists (the Ozempic/Wegovy/Mounjaro drug class) and male fertility, pulling together mechanistic, animal, and human data through May 2025. The authors found 16 clinical studies that met their criteria, on top of rodent and in vitro work, and conclude the drugs "likely" help fertility in men with obesity or diabetes. That conclusion outruns what 16 heterogeneous clinical studies, many small and uncontrolled, can actually support.

Claims

• GLP-1 receptors are expressed in testicular tissue, providing a plausible biological target.
• In obese/diabetic rodent models, GLP-1RAs improved spermatogenesis, hormone profiles, and sperm function, with proposed cAMP/PKA and PI3K/Akt signaling pathways.
• In vitro experiments showed improved sperm motility and Sertoli cell metabolism with GLP-1RA exposure.
• 16 clinical studies were identified; some reported improved semen parameters and testosterone levels in obese, hypogonadal men, but results across studies were inconsistent.

Study Quality

This is a narrative review, not a systematic review or meta-analysis: the authors describe a "comprehensive literature search" across PubMed, MEDLINE, and Embase, but there's no PRISMA flow diagram, no formal risk-of-bias scoring, and no pooled effect estimate. The abstract doesn't report sample sizes, designs, or funding sources for the 16 clinical studies individually, so readers can't tell how much of the "clinical evidence" rests on small case series versus larger cohorts. The mechanistic and rodent data are the most solid part of the paper, but rodent obesity/diabetes models don't reliably predict human reproductive outcomes, and the paper's own conclusion, that GLP-1RAs "likely" benefit fertility, is a judgment call the cited evidence doesn't clearly support given the acknowledged heterogeneity.

Red Flags

• Narrative review methodology dressed up with review-of-review language ("comprehensive literature search") but no systematic review rigor (no PRISMA, no bias assessment, no pooled analysis).
• The 16 included clinical studies are described only in aggregate, no breakdown of sample sizes, study designs, or individual funding sources is given in the abstract.
• "Heterogeneous results" in human studies is acknowledged, then the conclusion still asserts GLP-1RAs "likely" benefit fertility, a stronger claim than the underlying data supports.
• No funding source disclosed for the review itself.
• Senior author consults for a pharmaceutical company (Endo), which does not make GLP-1RAs but does make other products relevant to male reproductive/sexual health, worth noting as a general industry tie.

Strengths

• Addresses a genuine clinical gap: GLP-1RA use is exploding, and their effect on male reproductive health is understudied.
• Integrates three levels of evidence, mechanistic, preclinical, and clinical, rather than just summarizing human trials.
• Explicitly flags the limited and heterogeneous nature of the clinical data rather than hiding it.
• Identifies a plausible, receptor-based mechanism (testicular GLP-1 receptor expression) rather than relying on correlation alone.

Verdict

Useful as a map of where the GLP-1RA-fertility research stands, but not as evidence that these drugs improve fertility. The rodent and in vitro mechanistic data are real and worth watching; the human data are thin, inconsistently reported, and don't back the review's own "likely beneficial" framing. Read it for the lay of the land, not for a verdict on efficacy, that verdict doesn't exist yet.