GLP-1 Receptor Agonists and Tirzepatide in Men Seeking Fertility: A Structured Narrative Review and Proposed Clinical...

Glucagon-like peptide-1 (GLP-1) receptor agonists and the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist tirzepatide are increasingly used to treat obesity and type 2 diabetes in men of reproductive age, but practical guidance for counseling men planning fatherhood remains limited. This structured narrative review distinguishes endocrine, semen, sexual-function, and clinical fertility outcomes. In metabolically impaired men, studies largely involving liraglutide or semaglutide report increases in total testosterone; free-testosterone findings are inconsistent, and the available small short-term studies did not show the marked gonadotropin suppression expected with exogenous testosterone. Some studies report favorable changes in semen parameters, but samples are small, populations heterogeneous, and medication effects cannot be separated reliably from weight loss. The present search identified no adequately powered GLP-1-specific prospective study that prespecified sperm DNA fragmentation, natural conception, assisted-reproduction outcomes, clinical pregnancy, or live birth. Sexual-function findings are mixed and do not establish causality. Evidence on paternal preconception exposure is insufficient, and pregnancy-related label precautions do not by themselves establish risk from paternal exposure. No eligible controlled tirzepatide-specific study assessing semen or clinical fertility outcomes was identified by this search. These therapies should be used for established metabolic indications, not as male infertility treatments. The proposed framework is author-developed, evidence-informed, non-validated, and intended for individualized counseling and prospective evaluation.