What are the benefits and risks of GLP-1 medicines for men with obesity-related low testosterone?

Benefits

Weight loss may address an underlying driver

Obesity can be associated with functional, or secondary, hypogonadism: testosterone is lower in the setting of excess weight and metabolic dysfunction, without a separate primary testicular cause. Weight reduction may ease that suppression. It may also improve blood sugar regulation, sleep-related breathing problems, blood pressure, and other factors that can affect sexual health and energy. Those are potential benefits of treating obesity; they do not mean every symptom is caused by testosterone.

The Endocrine Society's 2026 statement on testosterone replacement therapy says that, for obesity-related hypogonadism (BMI over 27) without another cause, weight loss is typically first-line. It also emphasizes that a diagnosis needs compatible symptoms plus accurately measured, repeatedly low testosterone—not a single number.

Testosterone markers may move in a favorable direction

A 2025 systematic review and meta-analysis by Hamed et al. found that GLP-1 agonists were associated with higher bioavailable testosterone. Results for free testosterone and SHBG were inconclusive, and the evidence base was small. This suggests a possible metabolic pathway to improvement, not a guaranteed response.

A separate 2025 systematic review and meta-analysis in Andrology found an increase in total testosterone across seven studies involving 680 people. The authors noted important limitations and did not establish a direct drug effect on the testes. In other words, a higher testosterone result may reflect weight and metabolic changes rather than GLP-1 medicines directly "boosting" testicular function.

Fertility research is early

A June 2026 Endocrine Society news release, reporting research presented at ENDO 2026, described possible fertility improvements in men with obesity. The release also makes the boundaries clear: only a small number of trials were available, and GLP-1 medicines were not evaluated as treatments for male infertility or hypogonadism. Any fertility benefit is likely indirect, through weight and metabolic health, rather than a proven fertility effect.

Risks and who should not use them

GLP-1 medicines can cause nausea, vomiting, diarrhea, constipation, abdominal discomfort, reduced appetite, and dehydration. More serious concerns can include pancreatitis, gallbladder problems, kidney injury related to dehydration, severe gastrointestinal symptoms, and allergic reactions. Low blood sugar is more likely when a GLP-1 medicine is combined with insulin or certain other diabetes medicines. These medicines can also slow stomach emptying, which matters for some people and around some procedures.

A clinician needs to review personal risks, other medicines, and the specific product. Semaglutide- and tirzepatide-containing products carry a boxed warning related to thyroid C-cell tumors; people with a personal or family history of medullary thyroid carcinoma or with multiple endocrine neoplasia syndrome type 2 should not use them. A history of pancreatitis, gallbladder disease, severe gastrointestinal disease, kidney problems, or an eating disorder also deserves careful review rather than self-treatment.

Do not use a GLP-1 medicine to replace a proper low-testosterone evaluation. Symptoms such as low libido, erectile difficulty, fatigue, depressed mood, or reduced muscle mass have many possible causes. Testosterone testing should be done accurately and interpreted with the clinical picture; a low result may need confirmation. Men trying to preserve fertility should raise that goal before considering testosterone replacement, because TRT can reduce sperm production.

TRT is a separate decision with separate evidence and risks. The Endocrine Society statement discusses the TRAVERSE trial's cardiovascular and pulmonary-embolism/fracture safety context for TRT; those findings are not proof of benefit or risk for GLP-1 medicines.

What is unknown

It is not known whether GLP-1 medicines reliably normalize testosterone, improve symptoms, or improve fertility in men with obesity-related low testosterone. The available studies are small, differ in drugs, doses, follow-up, and participant characteristics, and do not prove that changes came directly from the medicine. They also do not establish a best dose or duration for treating low testosterone, or show that GLP-1 medicines treat primary testicular failure.

It is also uncertain what happens to testosterone, weight, and symptoms after a medicine is stopped. A testosterone change on a lab report is not the same as better sexual function, mood, fertility, or long-term health. More controlled studies are needed, especially trials designed specifically for men with confirmed obesity-related hypogonadism or infertility.

A licensed clinician can help determine whether obesity-related hypogonadism is a reasonable working diagnosis, check for other causes, and weigh expected benefits against the medicine's risks.

Medically reviewed by: Ana Argote, BSN, R.N.

Sources

1. STUDY/REVIEW — Hamed et al. (2025). "Effect of GLP-1 agonists on testosterone levels: a systematic review and meta-analysis." BMC Urology. PubMed · DOI
2. STUDY/REVIEW — Gianmaria Salvio, Alessandro Ciarloni, Nicola Ambo, Monia Bordoni, Michele Perrone, Silvia Rossi, and Giancarlo Balercia (2025). "Effects of glucagon-like peptide 1 receptor agonists on testicular dysfunction: A systematic review and meta-analysis." Andrology. PubMed · DOI
3. NEWS — Endocrine Society (2026, June 13). "Clinical trials suggest GLP-1s may improve fertility in men with obesity." Endocrine Society. News release
4. SOCIETY STATEMENT — Endocrine Society (2026, July 16). "Statement on Testosterone Replacement Therapy." Endocrine Society. Statement
5. REGULATOR — U.S. Food and Drug Administration (FDA). "Compounding and FDA: Questions and Answers." FDA. FDA guidance