GLP-1 Drugs and/or Losing Weight Boosts Testosterone

You’ve heard the old question: “Which came first: the chicken or the egg?” The same thing could be said about testosterone. What increases testosterone levels? Is it anti-obesity GLP-1 drugs such as semaglutide (Wegovy) or tirzepatide (Zepbound), or is it weight loss itself that boosts testosterone?

Reversing Low T with Anti-Obesity Drugs:

The Endocrine Society held its annual meeting in San Francisco the week of July 14, 2025. Researchers at SSM Health St. Louis University Hospital reported on a study of 110 overweight men. These subjects were taking semaglutide (Ozempic, Wegovy), dulaglutide (Trulicity) or tirzepatide (Mounjaro, Zepbound) to manage diabetes and/or obesity.

The researchers analyzed the records of subjects who were taking the weight loss or diabetes drugs for 18 months. Their testosterone levels were measured before and during their treatment.

The lead author, Dr. Shellsea Portillo Canales, told Healthline:

“We found that men treated with GLP-1–based weight loss therapies, such as semaglutide, dulaglutide, and tirzepatide, experienced significant increases in both total and free testosterone levels. These findings suggest that in men with obesity or type 2 diabetes, incretin-based therapy [GLP-1 and GIP receptor agonists] may help restore healthy testosterone levels, particularly when low testosterone is related to obesity.”

Dr. Canales went on to say:

“The increases we observed were more modest than what you would typically see with testosterone replacement therapy. However, they occurred naturally, without testosterone replacement therapy (TRT), and likely reflect the body recovering its normal hormone production as weight and insulin resistance improved.”

Drugs OR Weight Loss Boosts Testosterone?

So, how well did the drugs work? These guys were obese. The average body mass index (BMI) of the bunch was around 35. What is a “normal” BMI you ask? Somewhere between 18 and 25 would be considered acceptable. Anything over 30 is considered obesity!

The guys in this study lost about 10% of their weight over the year and a half of the study period. That was roughly 25 pounds. Their testosterone levels went up about 17%.

Healthline asked Dr. Beverly Tchang, an obesity expert and endocrinologist at Weil Cornell Medicine her opinion about the study results. She stated:

“This tracks with what we would expect based on how weight loss affects testosterone concentrations.”

A study of bariatric surgery reinforces this observation. It reported that this kind of intervention for obesity leads to an increase in testosterone levels (Obesity Surgery, May, 2025).

Weight Loss Boosts Testosterone!

A systematic review and meta-analysis of “Obesity and sexual desire” was published in the Journal of Sexual medicine, May 10, 2025.

It notes:

“The meta-analysis of plasma total testosterone levels from studies that present results before and after selected diets showed a strong impact of diet on the increase in testosterone levels after interventions. There was a significant impact of the level of plasma total testosterone on the variance of sexual desire in the SDI [Sexual Desire Inventory] questionnaire.”

Conclusions:

“A potential association between sexual desire and body weight exists. Weight loss interventions, including dietary changes and bariatric surgery, significantly increased both sexual desire and plasma total testosterone levels. Additionally, variations in plasma total testosterone levels had a significant effect on the variability of sexual desire in obese men.”

More Reason to Lose Excess Weight!

Losing weight may have a surprising benefit for middle-aged men. A study of nearly 900 men at risk of type 2 diabetes compared the effects of diet and exercise in one group, metformin in another group and a placebo control in the third group. Both metformin and lifestyle changes were able to delay the onset of type 2 diabetes.

In addition, however, men who controlled their blood sugar with diet and exercise were much less likely to have low testosterone. At the beginning of the study, 20 percent of them had low levels of this important hormone. After a year of lifestyle modification that resulted in weight loss, only 11 percent had low testosterone.

This male hormone is related to muscle and well-being as well as to sexual interest and performance. There was no change in the incidence of low testosterone in either of the other two groups.
[The Endocrine Society’s 94th Annual Meeting in Houston, June 25, 2012]

Final Words:

Durham, NC was once known as the “Diet Capital” of the world. That’s because of the Rice Diet Program and the Duke Lifestyle and Weight Management Center. They were renowned for helping people lose weight when all other programs failed. People also came from all over to the world to shed pounds at a residential wellness center called “Structure House.”

We had the opportunity to interview the founder of Structure House, Dr. Gerald Musante, on numerous occasions. He was renowned for stating people had to “change their relationship with food” if they really wanted to lose weight.

There were long-running rumors that overweight patients who came to Durham shed significant pounds and had their libidos light up. We cannot verify such rumors, but the fact that testosterone levels seem to rise when people lose weight might not be a coincidence.

If you know someone who is overweight, you might want to share this article with them. Knowing that losing weight can improve testosterone levels naturally could be just the motivation they need. When testosterone levels normalize, people have better bone density, more energy, improved muscle mass and better sexual function. Here is a link to an article that will provide much more information about testosterone.