Man standing on weight scale with numbers spinning

Does Testosterone Make You Gain Weight?

The hormone can help pounds peel off, but there’s a catch.

If you’ve been struggling to lose weight and feel like you have virtually no energy, it’s possible you have low testosterone. A physician may recommend trying testosterone replacement therapy (TRT) to help you feel like yourself again. But the question is, does testosterone make you gain weight? According to physicians, having more of the hormone can actually help you hit your weight loss goals, but that’s only possible if other healthy habits are in the mix.

Urologist Thomas Masterson, M.D. says taking testosterone can help increase lean muscle mass and decrease fat mass. “If you were to just take testosterone and do nothing, you’ll probably gain weight,” he says. That’s largely because testosterone can increase your appetite, as well as cause fluid retention (water weight). Also, because muscle is denser than fat, it weighs more than fat by volume.

“But if you take testosterone in combination with a regimented exercise plan, you’d actually expect to lose weight and waist circumference,” he explains.

Men with low testosterone (T) tend to be heavier. Low T is strongly associated with increases in abdominal obesity, body mass index (BMI), and waist circumference. However, TRT can help overweight men with low T lose reverse all of these weight-related issues

One study found that long-term TRT safely and effectively leads to sustained weight loss in obese men with hypogonadism (low testosterone) (1). The researchers also noted this weight loss could potentially reduce the men’s risk of heart disease, stroke, and diabetes.

Ahead, both Masterson and urologist Justin Dubin, M.D. dig into how low testosterone can be a driver for weight gain, and how TRT may lead to weight loss.

About the Experts

Justin Dubin, M.D., is a urologist and men’s health specialist in South Florida and co-host of the Man Up Podcast.

Thomas Masterson, M.D., is an assistant professor of urology at the Desai Sethi Urology Institute in the Miller School of Medicine at the University of Miami.

Why Can Low Testosterone Lead To Weight Gain?

Low T is associated with more fat buildup around your gut. Fat tissue contains aromatase, an enzyme that converts testosterone to estradiol (the primary form of estrogen), says Dubin. Estrogen is often considered a women’s hormone, but men need it to help regulate sex drive, sperm production, and erectile function.

“You actually lose testosterone by having more fat,” Dubin says.

Here’s why: The more fat you have, the greater potential aromatase will be converted from testosteroneT into estrogen, Dubin explains. Having too much estrogen can lead to developing gynecomastia (doctor-speak for man boobs).

“The question becomes: Do I have a low T because I’m overweight? Or am I overweight because I have low T?” Dubin says, adding it’s similar to the famous question: what came first, the chicken or the egg?

Men who are overweight and have symptoms of low testosterone (such as low sex drive, erectile dysfunction, fatigue, and hair loss) may be told by their provider to eat healthy and exercise, and while that’s key to weight loss it doesn’t always paint the full picture. If these guys have low T, they likely won’t have as much energy, Dubin says. This can make it more difficult to get motivated to exercise regularly and, ultimately, lose weight. “It’s kind of a cyclical problem,” he adds.

To further illustrate the relationship between low T and weight gain, Dubin points to prostate cancer patients. Some prostate cancer patients are put on a treatment called androgen deprivation therapy (ADT) to lower their testosterone levels. Why? Testosterone can actually fuel the growth of prostate cancer cells. So the ADT tackles the cancer, but also leads to weight gain and loss of muscle.

One study on men with prostate cancer who were put on ADT for a year experienced a 22 percent increase in visceral abdominal fat and a 13 percent increase in subcutaneous abdominal fat (2). For context, visceral fat is found deep within the abdominal organs and is linked to cardiovascular disease (3), while subcutaneous fat is the fat just under the skin that you can pinch.

How can you treat low testosterone?

If you have low T, which the American Urological Association defines as less than 300 nanograms per deciliter (ng/dL) accompanied by symptoms like weight gain, TRT can help increase those levels. TRT comes in many forms, including injections, gels, patches, troches, and pellets.

Improving sleep, stress management, and physical activity can all naturally boost T levels. Masterson also recommends avoiding high-calorie and processed foods to help keep your weight in check.

Hone’s at-home testosterone assessment is the simplest way to uncover whether your levels are low. If you qualify for treatment, TRT can be sent right to your door.  

How Can TRT Support Weight Loss?

The combination of belly fat and low testosterone is linked to an increased risk of metabolic syndrome, a cluster of conditions that raises your risk of heart disease, stroke, and type 2 diabetes.

The good news: Research shows weight loss from TRT can reduce the risk of these conditions (1). Dubin adds that studies indicate testosterone replacement therapy can help improve insulin resistance, reduce body fat, and improve cholesterol levels (4). “It seems like it can [also] positively improve your metabolism,” he notes, though it’s not quite yet clear how.

TRT can also support weight loss by contributing to increased muscle mass, which can support weight loss because muscle tissue burns more calories than body fat (5).

A systematic review found that men with obesity who were on TRT gained an average of 4.4 pounds on muscle. Their levels of low-density lipoprotein (LDL), or “bad” cholesterol also dropped (6).

Can You Gain Weight on TRT?

Dubin notes that while he has seen patients who have gained weight while on TRT, it’s usually because they weren’t following a healthy lifestyle.

“They’re like, ‘I feel much better, my energy’s back, my libido is back. I’m motivated to go to the gym, but I haven’t lost weight and haven’t gained muscle,’” Dubin says. He reminds them that developing healthy habits are crucial to maximizing TRT benefits.

Masterson agrees, adding that if you want to put on muscle you’ll need to put in the work.

In one study, researchers compared two groups of men put on TRT. One group exercised, the other didn’t. After 12 weeks the exercisers had fewer symptoms and higher T levels than the non-exercisers. Even better, they maintained the benefits after stopping TRT (7).

“I don’t want people to think that testosterone by itself is a silver bullet that’s going to fix everything,” Masterson says. “You still have to exercise and think about your diet if you want to meet weight loss and muscle gain goals.”