Skip to content
glp1.howSign in

Supportive Health

Testosterone replacement therapy (TRT)

Replacing testosterone in men with diagnosed hypogonadism — the men's form of HRT, given by gel, injection, patch, or pellet.

By the glp1.how editorial teamReviewed

Testosterone replacement therapy (TRT) replaces testosterone in men with hypogonadism — clinically low testosterone accompanied by symptoms — using gels, injections, patches, or pellets.

It is meant for a specific diagnosis. Much of the low testosterone seen with obesity is reversible without TRT, and weight loss (including on a GLP-1) often raises testosterone on its own. See the guide on HRT for men and GLP-1 medications. The Endocrine Society's guideline recommends diagnosing hypogonadism only in men with symptoms and consistently low testosterone levels (Bhasin et al., 2018 (external link)).

trttestosteronehrtmenglossary

Revision history

Updated 1 time since Sep 2, 2026 · show changes
  1. v2

    Body revised

  2. v1

    Change tracking began

Related guides

  • HRT for men (testosterone) and GLP-1 medications: what the connection really is · Low testosterone and excess weight are linked, but the cause often runs from the weight to the testosterone, and that changes when testosterone therapy actually helps. This guide covers who benefits from TRT and why losing weight on a GLP-1 can raise testosterone on its own.
  • How GLP-1 medications affect men vs. women: what the sex differences actually are · The same GLP-1 medication doesn't act quite the same in men and women. On average women lose more weight, report more side effects, and absorb more of the drug at the same body weight, differences driven partly by estrogen and testosterone. This guide covers what the research shows about sex differences in weight loss, tolerability, blood sugar and biology, and what it means for what you should expect.
  • Men's health on a GLP-1: testosterone, fertility, muscle, and the things worth watching · For men, losing weight on a GLP-1 can raise testosterone that obesity was holding down, and unlike testosterone therapy it seems to leave fertility intact. This guide covers what the research shows so far on testosterone, sexual function and sperm, muscle and bone, heart health and sleep apnea, and why the routine checkup matters more on these medications.
  • Hormone replacement therapy (HRT) and GLP-1 medications: an overview · HRT and GLP-1s keep coming up together because the times people look at hormones (menopause in women, low testosterone in men) are also times of weight and body-composition change. This overview explains what each does, who benefits, what weight loss does to testosterone, and how to plan the two together.
  • HRT for women and GLP-1 medications: menopause, weight, and body composition · Menopause shifts where the body stores fat and how well it holds muscle, the same ground a GLP-1 works on, so hormone therapy often comes up. This guide explains what HRT is for women, who benefits, the 2025–2026 FDA label changes, and how HRT does and doesn't overlap with GLP-1 weight management.
  • CPAP as the weight comes off: managing sleep apnea on a GLP-1 · Tirzepatide (Zepbound) roughly halved sleep apnea severity in the SURMOUNT-OSA trials, and 42 to 50% of participants reached the trial's definition of resolution. That still left many with apnea, and the trials never tested stopping CPAP for good. This guide covers why you shouldn't retire your machine on your own, how pressure and mask fit change as weight comes off, when and how a repeat sleep test happens, and how an OSA diagnosis affects Zepbound coverage (as of September 2026).

Related terms

  • Hypogonadism · A condition of low sex-hormone production. In men it means low testosterone with symptoms; importantly, the low testosterone that often accompanies obesity is frequently a reversible state ('pseudo-hypogonadism') rather than true, pathologic hypogonadism.
  • GLP-1 · A gut hormone (glucagon-like peptide-1) that stimulates insulin release, slows digestion, and reduces appetite; the target of drugs like semaglutide and liraglutide.

Was this helpful?

Improve this page