New Study Links GLP-1 Medications to Higher Testosterone and Better Sperm Count

Men taking GLP-1 medications for weight loss or diabetes may gain an unexpected benefit beyond improved metabolic health-better fertility, according to new research presented at the Endocrine Society's ENDO 2026 meeting.

Researchers found that after 24 weeks of GLP-1 treatment, men aged 18 to 65 with obesity experienced improvements in testosterone levels, sperm count, and sperm quality, including healthier size and shape. The findings suggest these widely used medications may positively influence male reproductive health, although experts stress that larger studies are still needed before GLP-1 drugs can be recommended specifically to treat infertility.

Male infertility contributes to more than half of infertility cases among couples who struggle to conceive. Researchers believe the benefits seen with GLP-1 medications may be largely driven by weight loss, which can improve hormone balance, particularly testosterone production. The drugs may also reduce inflammation and metabolic stress, both of which are known to impair sperm production.

Unlike testosterone replacement therapy, which can suppress sperm production despite increasing testosterone levels, GLP-1 medications could potentially improve both hormone levels and fertility simultaneously. However, researchers caution that the current study only included men with a high body mass index, so the findings cannot yet be applied to men of normal weight.

Experts also note that obesity is not the only cause of male infertility. Hormonal disorders can sometimes contribute to weight gain rather than result from it, making a proper fertility evaluation important before starting treatment. They also caution that rapid weight loss—whether through bariatric surgery or, in some cases, GLP-1 medications—may temporarily affect fertility by signaling to the body that conditions are not ideal for reproduction.

Alongside medical care, maintaining a healthy weight, exercising regularly, eating fewer ultra-processed foods, getting enough sleep, avoiding smoking and excessive alcohol, limiting exposure to environmental toxins, and reducing frequent exposure to high heat, such as hot tubs, may all help support male fertility and overall reproductive health.

REFERENCE: Clinical trials suggest GLP-1s may improve fertility in men with obesity; ENDO 2026- Endocrine Society’s annual meeting in Chicago, Ill; https://www.endocrine.org/news-and-advocacy/news-room/2026/natesh-press-release-endo-2026