Does Testosterone Therapy Cause Weight Gain?

Many men look into testosterone therapy partly because of their weight. Low testosterone is linked to more fat around the middle, less muscle and lower energy, so it is natural to hope treatment will help. It is just as natural to worry about the opposite: that a hormone will add pounds, cause bloating or make weight harder to control.

The answer depends on what you measure. Testosterone changes what your body is made of more than what it weighs, and the first months of treatment can look different on the scale than they do in the mirror. Below we look at what the research shows, why weight can rise early on, and which side effects deserve more attention than the number on the scale.

What the research shows

In men with low testosterone, treatment tends to add muscle and reduce fat at the same time. Because the two partly cancel out, body weight often changes very little, even when body composition improves.

The largest summary of the evidence is a meta-analysis that pooled 59 randomized controlled trials of testosterone treatment. Compared with men who did not receive it, men on testosterone had less fat mass and more lean mass. Their average body weight, waist size and BMI did not change significantly.

The same analysis found lower fasting blood sugar and less insulin resistance, with the largest effect in younger men and in men who already had metabolic problems.

A second meta-analysis, this time of observational studies, did find gradual weight and waist reductions over time. The authors were careful to say this needs confirming in trials designed to test it.

So the fair summary is that testosterone reliably shifts weight from fat toward muscle, and it may help with weight loss over the long term, but it is not a weight loss treatment.

Why the scale can go up at first

• More muscle. Muscle is denser than fat. Gaining a few pounds of muscle while losing a similar amount of fat can leave your weight unchanged or slightly higher.
• Fluid. Some men hold a little extra water in the first weeks of treatment. It usually settles, and your clinician will ask about swelling at follow-up.
• More appetite and energy. Some men find they eat more as their energy returns. That is a habit question, not a side effect of the hormone itself.

Because of this, the scale is a poor measure of progress on TRT. Waist circumference, how your clothes fit and, where available, a body composition scan tell you more.

Low testosterone and weight are connected both ways

Low testosterone makes it easier to gain fat, especially around the middle. Extra body fat also lowers testosterone. In a meta-analysis of weight loss studies in men, losing weight through diet or surgery raised testosterone levels, and the more weight men lost, the bigger the rise.

This matters if you have both excess weight and low testosterone. In some men, losing weight is enough to bring testosterone back into range. In others, both need treating. Your hormone panel and your history help your clinician decide which applies to you, and our medical weight loss program can run alongside TRT when it does.

Side effects that matter more than weight

Testosterone therapy has side effects that are more important to monitor than a few pounds on the scale.

• Higher red blood cell count. Testosterone can raise hematocrit, the proportion of your blood made up of red cells. The Endocrine Society recommends checking it before treatment and again 3 to 6 months after starting. If it goes above 54%, treatment is paused until it comes down and then restarted at a lower dose.
• Sleep apnea. The same guideline recommends against starting testosterone in men with untreated severe obstructive sleep apnea. If you snore heavily or wake up tired, mention it at your consultation.
• Acne and oily skin. Common in the first months, usually mild.
• Prostate. For men 40 and older, the guideline recommends discussing prostate cancer monitoring before starting and checking again 3 to 12 months into treatment.

These are the reasons TRT should only be started after a proper hormone panel and continued with regular follow-up labs.Clinical Endocrinology & Metabolism found that fluid retention peaked at around 3-6 months into therapy before stabilizing.

Getting the best result

How TRT works at SaltMD

1. A 30-minute consultation, in person in Atlanta or by video anywhere in the US.
2. A hormone panel, with blood drawn at a lab near you or at our office. If you have had blood work in the past 90 days, your clinician can review those results instead.
3. A treatment plan, if your results and symptoms support it. Your prescription is filled by a partner pharmacy and shipped to you.
4. Follow-up labs to check your testosterone, hematocrit and other markers, and adjust the dose.

Learn more about testosterone replacement therapy or book a consultation.

Sources

• Corona G et al. Testosterone supplementation and body composition: results from a meta-analysis study. Eur J Endocrinol. 2016;174:R99-R116. doi:10.1530/EJE-15-0262
• Corona G et al. Testosterone supplementation and body composition: results from a meta-analysis of observational studies. J Endocrinol Invest. 2016;39(9).
• Corona G et al. Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis. Eur J Endocrinol. 2013;168(6):829-843. doi:10.1530/EJE-12-0955
• Bhasin S et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. doi:10.1210/jc.2018-00229