GLP-1 Medications and Fertility: What Men and Women Need to Know

Roughly one in six couples worldwide struggles with infertility, and the research is increasingly clear that excess body weight sits at the center of many of those struggles. Against that backdrop, the explosion of GLP-1 receptor agonists — semaglutide, tirzepatide, dulaglutide — has raised a genuinely important question: beyond shrinking waistlines, do these medications move the needle on reproductive health? The answer, according to a growing body of evidence, is cautiously promising — but far more nuanced than the headlines suggest.

A 2024 review published in the International Journal of Molecular Sciences by Pavli, Triantafyllidou, Kapantais, and colleagues took a sweeping look at what medical weight loss — including GLP-1 receptor agonists — does to fertility outcomes in both sexes. Their conclusion was straightforward: even modest, medication-assisted weight loss produces meaningful improvements in reproductive hormone profiles, menstrual regularity, ovulation rates, and — in men — sperm quality and sexual function. That finding matters whether you’re on a GLP-1 medication, working through a structured diet, or hitting the gym five days a week. The mechanism that restores fertility is largely the same: reducing the metabolic burden that excess adiposity places on the endocrine system.

How Obesity Disrupts Fertility — And Why Weight Loss Reverses It

Adipose tissue isn’t passive storage. It’s metabolically active, secreting inflammatory cytokines, converting androgens to estrogens via aromatase, and disrupting the hypothalamic-pituitary-gonadal axis in ways that impair reproductive function in both sexes. In women, this manifests most commonly as anovulatory cycles, polycystic ovarian syndrome, and poor implantation rates. In men, elevated estrogen from peripheral aromatization suppresses testosterone and LH, while oxidative stress from chronic low-grade inflammation degrades sperm motility and morphology.

The 2024 review by Pavli et al. synthesized evidence across multiple weight-loss medications and found that the fertility outcomes most responsive to medically induced weight loss are, on the female side, hormonal normalization, menstrual cyclicity, ovulation, and pregnancy rates. On the male side, the clearest improvements appear in reproductive hormone profiles — particularly testosterone — along with sperm motility, movement parameters, and morphology, as well as overall sexual function. The duration of treatment and the degree of weight loss both matter: this isn’t a one-injection fix. Sustained, meaningful fat loss is what shifts the hormonal environment enough to restore reproductive function.

GLP-1 receptor agonists enter this picture as one of the more effective tools for achieving that sustained fat loss, particularly in patients who haven’t responded to lifestyle intervention alone. The same review notes that newer GLP-1 RAs have shown encouraging early signals around improved ovulation rates and menstrual cycle regulation — effects that may go beyond simple weight loss and point toward a possible direct action on reproductive tissue. GLP-1 receptors have been identified in the ovary, endometrium, and testicular tissue, which raises the question of whether these drugs interact with the reproductive system through mechanisms independent of fat reduction. The authors are careful to note that human data remains limited and more controlled trials are needed before any direct reproductive effect can be confirmed.

The Sexual Function Question — What the Evidence Actually Shows

Parallel to the fertility conversation is a related but distinct question: what do GLP-1 medications do to libido and sexual function? A 2026 narrative review in Sexual Medicine Reviews by Merhi and colleagues tackled this directly, synthesizing both preclinical and clinical data. The results are genuinely mixed, and the divergence between animal models and human data is worth paying close attention to.

In rodent studies, the GLP-1 receptor agonist exendin-4 suppressed sexual interaction behaviors through activity in brain regions governing reward and motivation — the laterodorsal tegmental area, posterior ventral tegmental area, and nucleus accumbens shell. Activation of the nucleus of the solitary tract reduced pre-sexual, sexual, and post-sexual behaviors, accompanied by elevated corticosterone and altered monoamine turnover. In plain terms: in animals, GLP-1 receptor activation appears to dampen sexual motivation through neuroendocrine and stress-related pathways.

Human data tells a more complicated story. Pharmacovigilance analyses from the FDA Adverse Event Reporting System did capture reports of erectile dysfunction, decreased libido, and orgasmic dysfunction among GLP-1 RA users — but disproportionality analyses showed these associations were not statistically significant, meaning the signal didn’t stand out compared to what you’d expect from any widely used medication. A social media netnographic analysis found that users self-reported variable libido effects: some experienced enhanced desire, which they attributed to weight loss, improved body image, and higher energy. Others reported decreased sexual interest. These are self-reported, uncontrolled observations, but they reflect real-world heterogeneity that clinical trials often miss.

The most rigorous piece of data in the Merhi review involves a randomized, double-blind crossover trial in healthy lean men, where dulaglutide — a GLP-1 receptor agonist — had no measurable effect on sexual desire, hypothalamic-pituitary-gonadal axis hormones, or semen parameters. This suggests that in metabolically healthy men, GLP-1 RAs do not directly impair sexual or reproductive function. Where things get murkier is in men who are obese, insulin-resistant, or already dealing with hypogonadism — populations where the baseline hormonal environment is already compromised, and where weight loss itself (however achieved) tends to improve testosterone and libido regardless of the tool used.

For women, the data is even thinner. The Merhi review identifies possible female sexual side effects through clinical case reports, but controlled trials are essentially absent. This is a significant gap in the literature. The authors call explicitly for mechanistic and controlled clinical studies, noting that outcomes appear to be shaped by sex, metabolic status, the specific GLP-1 drug used, and psychosocial factors — all variables that make generalization difficult.

One practical note worth emphasizing: both reviews are consistent on one point that should not be glossed over. GLP-1 receptor agonists are not recommended during pregnancy and should be discontinued when a pregnancy is planned. If fertility improvement is the goal, these medications are a means to an end — restoring metabolic health to a point where conception becomes more viable — not a medication to stay on through conception and gestation. Anyone navigating this decision should be doing so in close communication with both a prescribing physician and a reproductive endocrinologist.

For men specifically, the broader takeaway from this research is that reproductive health is a metabolic health story. Elevated body fat, insulin resistance, chronic inflammation, and poor sleep are the variables most reliably associated with impaired sperm quality and suppressed testosterone. GLP-1 medications can accelerate the metabolic correction that restores hormonal function, but so can structured resistance training, caloric deficit through whole-food nutrition, and improvements in sleep quality. The mechanism — reduced adiposity, lower systemic inflammation, normalized insulin signaling — is largely the same across approaches. GLP-1 is one path to that destination, not the only one.

The Takeaway

The science on GLP-1 medications and fertility is still developing, but the directional signal is encouraging. Weight loss — whether driven by medication, nutrition, or training — reliably improves reproductive hormone profiles, ovulation, sperm quality, and sexual function in people carrying excess body fat. GLP-1 receptor agonists appear to support these outcomes, and may have direct effects on reproductive tissue beyond what weight loss alone explains, though human trials haven’t confirmed this yet. On sexual function, the honest answer is that the data is mixed, animal models and human outcomes diverge, and the strongest evidence in lean men shows no impairment. If you’re using or considering a GLP-1 medication and fertility is part of your health picture, the conversation starts with your doctor — and it ends, whenever pregnancy becomes the goal, with stopping the medication before conception.