Do GLP-1s Affect Libido, Erectile Function, and Testosterone? Evidence [2026]

GLP-1 drugs like Ozempic, Wegovy, Zepbound, and Mounjaro do affect sexual function and hormones, but the direction is not the same for everyone. Some people see libido, erections, and testosterone improve as they lose weight, while others report lower desire, trouble with erections, or no change at all. This guide walks through what the actual studies show, where the evidence is strong, and where it is thin and conflicting.

The short version, with honest caveats

Most of what happens to sex drive, erectile function, and testosterone on a GLP-1 is downstream of weight loss, not a direct drug effect. Carrying a lot of extra weight lowers testosterone in men and disrupts sex hormones in women. Lose the weight, and those numbers often move back toward normal. That is the most consistent finding in the research.

But there is a real signal pointing the other way. One large database study found higher rates of new erectile dysfunction in non-diabetic men who started semaglutide for weight loss. And a steady stream of patient reports describes dropped libido, anorgasmia, and arousal problems. These reports are harder to pin down because they rely on self-reporting and have not been confirmed in controlled trials. So the picture is genuinely mixed. Read on for the specifics.

How GLP-1 drugs could touch sexual function

GLP-1 receptor agonists were built to manage blood sugar and reduce appetite. They were not designed to change your sex life. Any effect on libido, erections, or testosterone is mostly indirect. Here are the main pathways researchers point to.

Weight loss and hormones

This is the big one. In men, fat tissue contains an enzyme called aromatase that converts testosterone into estrogen. More fat, more conversion, lower testosterone. Excess weight also suppresses the brain signals (LH and FSH) that tell the testes to make testosterone. Doctors call this "male obesity-related secondary hypogonadism," and the key word is secondary — it is caused by the obesity, not a broken testicle or pituitary gland.

Because it is secondary, it is often reversible. A 2013 meta-analysis in the European Journal of Endocrinology found that meaningful weight loss reliably raised testosterone, with low-calorie diets and bariatric surgery both producing significant gains (Corona et al., 2013). Roughly, every kilogram of weight lost nudges total testosterone up by a small but real amount. GLP-1 drugs drive a lot of weight loss, so the same logic applies.

In women, obesity and insulin resistance can throw off the balance of estrogen, androgens, and sex hormone-binding globulin (SHBG). This matters a lot in PCOS, where high androgens and insulin resistance go together. Weight loss can help rebalance things, though it can cut both ways depending on the person.

Blood flow and the vascular system

Erections are a plumbing problem before they are a hormone problem. They depend on healthy blood vessels and nitric oxide signaling. GLP-1 drugs improve blood sugar, blood pressure, and cardiovascular risk, and good vascular health supports erectile function. This is one reason GLP-1s may help erections in men with diabetes, where blood vessel damage is a common cause of ED.

The brain and reward

GLP-1 receptors sit in brain regions that handle reward and motivation. The same dampening of food cravings that makes these drugs work for weight loss might, in theory, blunt other appetites, including sexual desire. This is a leading hypothesis for why some people report lower libido. It is biologically plausible but not proven.

Side effects that get in the way

Nausea, fatigue, bloating, and feeling generally off — especially in the first weeks and after dose increases — can flatten anyone's interest in sex. This is not a hormone effect. It is just feeling unwell. It tends to fade as the body adjusts.

Testosterone: where the evidence is strongest

Of the three topics in this guide, the testosterone story is the most solid, and it leans positive for men with obesity.

A 2025 systematic review and meta-analysis in BMC Urology pooled four studies (about 219 men before treatment, 216 after) and found that GLP-1 receptor agonists significantly raised bioavailable testosterone and lowered HbA1c (Pooled meta-analysis, BMC Urology, 2025). The catch: free testosterone change just missed statistical significance, and SHBG did not move significantly. So the benefit is real but partial, and it is built on a small number of studies.

At the 2025 Endocrine Society meeting, researchers reported on 110 men (average age 54) with obesity and type 2 diabetes who took semaglutide, dulaglutide, or tirzepatide. Over 18 months they lost about 10% of body weight, and testosterone levels rose substantially. The lead author called it "among the first" evidence that low testosterone can be reversed with anti-obesity medication. Worth noting: this was a conference presentation, not a peer-reviewed, placebo-controlled trial, so treat it as suggestive rather than settled.

A 2025 randomized controlled trial published in Diabetes, Obesity and Metabolism compared semaglutide against testosterone replacement therapy (TRT) in men with type 2 diabetes, obesity, and functional hypogonadism (Gregorič et al., 2025). Both treatments raised total testosterone and improved symptoms. The interesting divergence was sperm: semaglutide improved the share of normally shaped sperm, while TRT reduced sperm concentration and count. That last point matters for any man who still wants to father children, because TRT can suppress fertility while semaglutide may not.

Measure	What GLP-1s do	Evidence strength
Bioavailable testosterone (men)	Significant increase	Moderate — meta-analysis of 4 small studies
Free testosterone (men)	Slight rise, not statistically significant	Weak/mixed
SHBG	No significant change	Weak
Total testosterone (men with obesity)	Rises with ~10% weight loss	Moderate — consistent with weight-loss literature
Sperm quality	Improved morphology in one RCT; better fertility profile than TRT	Early/promising, one small trial

The honest summary: if you are a man with obesity and low testosterone driven by your weight, a GLP-1 plus real weight loss will probably raise your testosterone. That is a reasonable expectation. It is not a testosterone drug, and it will not fix low T that has a different cause.

One more nuance worth understanding. Researchers keep asking whether GLP-1s raise testosterone only through weight loss, or whether the drug does something extra on top of that. A 2023 analysis in Diabetes, Obesity and Metabolism found hormonal improvements in men on semaglutide that were partly, but not entirely, explained by the pounds lost. That hints at a possible direct effect on the hypothalamic-pituitary-gonadal axis — the chain of brain and gland signals that controls testosterone production. The hint is interesting but unproven. For now, assume weight loss is doing most of the work, and any bonus direct effect is a maybe.

It also matters how fast and how much weight you lose. The testosterone literature is consistent that bigger weight loss produces bigger hormonal gains, and that younger, more obese, non-diabetic men respond the most. That same group, though, is the one flagged for erectile trouble in the database study below. So the very situation that gives the largest testosterone payoff may also carry the most short-term sexual risk during the rapid weight-loss phase. That tension is real, and it is why monitoring during the first several months makes sense.

Erectile function: the genuinely mixed signal

Here the evidence splits, and you should know both sides.

The concerning study. A TriNetX database analysis, published in 2025 in the International Journal of Impotence Research, looked at non-diabetic obese men aged 18 to 50 who were prescribed semaglutide for weight loss (TriNetX study, 2025). Comparing 3,094 semaglutide users to matched controls, the rate of new ED or starting a PDE5 inhibitor (like Viagra) was 1.47% versus 0.32% — a relative risk of about 4.5. Testosterone deficiency was also more common (1.53% vs 0.80%, relative risk about 1.9).

That 4.5x figure sounds alarming, so read the fine print. The absolute rates are low: about 1.5 in 100 versus 0.3 in 100. This is an observational database study, not a randomized trial, so it can show association but not cause. Men who seek out semaglutide may differ from those who do not in ways the data cannot fully capture. And it was specifically non-diabetic men.

The reassuring side. In men with diabetes, the picture flips. Diabetes is a leading cause of ED through nerve and blood vessel damage. By improving blood sugar and vascular health, GLP-1s may actually help erections in this group. A 2025 review in Biomolecules titled "Friend or Foe?" weighed the vascular benefits against the reported harms and concluded the net effect on erectile function is genuinely uncertain and likely depends on the patient (GLP-1 and erectile function review, 2025).

So the takeaway: if you have diabetes-related ED, a GLP-1 might help. If you are a younger, non-diabetic man losing weight, there is a real, if low-probability, signal that erections could worsen, possibly tied to a drop in testosterone during rapid weight loss. Both can be true.

Libido: the weakest evidence and the loudest patient reports

This is where the data is thinnest and the anecdotes are loudest.

Clinical trials for semaglutide and tirzepatide did not flag changes in sex drive as a common side effect, and sexual dysfunction is not listed in the FDA prescribing information for Wegovy (Wegovy FDA label). On paper, the trials are quiet.

Real-world reports are not quiet. A Kinsey Institute survey found GLP-1 drugs were changing sex and dating for a large share of users, with effects going both ways (Kinsey Institute survey). Roughly 18% reported higher sexual desire and about 16% reported lower desire. Men were twice as likely as women to say their libido went up — and also twice as likely to say it went down. In other words, the average hides a lot of individual variation.

Pharmacovigilance data (FDA adverse event reports) has picked up a cluster of sexual complaints beyond ED, including reduced libido and orgasm problems, with semaglutide among the more frequently named drugs. Case reports describe anorgasmia starting after a GLP-1 was begun. But these are signals, not proof. Adverse event databases cannot tell you the rate, cannot prove the drug is the cause, and are skewed by who chooses to report.

A clinical review in 2025 proposed a "biopsychosocial" model: when desire drops on these drugs, it may get missed because patients and doctors are focused on the weight loss win, and because lower desire can be tangled up with nausea, fatigue, body image shifts, and changing relationships. Honest bottom line: we do not have good controlled data on GLP-1s and libido. Anyone who tells you these drugs definitely raise or definitely kill sex drive is overstating what is known.

Why is the trial data so quiet while the patient reports are so loud? A few reasons. The big weight-loss trials were not designed to measure sexual function, so they did not use the detailed questionnaires that would catch a change in desire or arousal. Side effects only get logged if someone reports them, and people rarely volunteer "my sex drive dropped" to a study coordinator focused on their weight. And the people most thrilled with their results may not connect a libido change to the drug at all. None of this proves the drugs flatten desire. It just means the trials were probably blind to it either way, which is exactly why the question stays open.

Effect	Men	Women	Evidence quality
Libido increase	Common in surveys, tied to weight loss and confidence	Reported but less often than men	Weak (survey/anecdote)
Libido decrease	Reported; possible brain reward + low-T link	Reported	Weak (survey/case reports)
Erectile function worse	Signal in non-diabetic men (RR ~4.5, low absolute rate)	N/A	Observational only
Erectile function better	Plausible in diabetic men via blood flow	N/A	Indirect/mechanistic
Arousal/orgasm problems	In FDA adverse event reports	In case reports	Very weak

Women specifically

The research on women is even thinner than on men. Most of what exists is indirect. Weight loss can improve hormonal balance, body image, and energy, all of which can lift sexual interest. In PCOS, GLP-1-driven weight loss may help restore ovulation and reduce androgen excess, which has knock-on effects for fertility and sexual health. But lower insulin can also shift sex hormone levels in ways that are not always favorable for desire.

Case reports describe both improved and worsened sexual function in women on tirzepatide. There is also early discussion of pelvic floor effects as body composition changes. The honest framing: for women, treat any sexual change on a GLP-1 as possible but unpredictable, and not well studied.

Who tends to see improvement vs. trouble

Patterns from the evidence, with the reminder that individuals vary:

More likely to improve:

Men with obesity and low testosterone caused by their weight
Men with diabetes and blood-flow-related ED
People whose sexual issues were driven by low energy, poor body image, or sleep apnea that improves with weight loss

More likely to have trouble:

Younger, non-diabetic men losing weight fast (watch for ED and a testosterone dip)
Anyone in the rough early weeks of nausea, fatigue, and feeling unwell
People whose low desire is tied to the brain-reward dampening these drugs cause

Practical steps if sexual function changes

Give it time. Early side effects that flatten libido often fade as your body adjusts and as the dose stabilizes.
Get testosterone checked if you are a man with new ED or low desire. A simple morning blood test for total and free testosterone can tell you whether low T is part of the picture. This is especially worth doing during rapid weight loss.
Protect against fast, sloppy weight loss. Crash-style weight loss with muscle loss can hurt hormones and energy. Eating enough protein and keeping resistance training matter here. See our guide on preventing muscle loss on GLP-1 medications.
Don't assume it's the drug. ED and low libido have many causes — stress, sleep, relationship issues, other medications. The drug is one suspect, not the only one.
Talk to your prescriber before stopping. If sexual side effects are a dealbreaker, options include adjusting the dose, switching agents, or adding treatment for ED. Stopping abruptly has its own trade-offs.

How this compares to alternatives

If raising testosterone is the actual goal, TRT raises it more directly and more reliably than a GLP-1. But TRT can suppress sperm production and shrink the testes, which matters for fertility. The semaglutide-vs-TRT trial above is a useful contrast: GLP-1 raised testosterone and improved sperm, while TRT raised testosterone but hurt sperm counts. For a younger man who wants both better testosterone and preserved fertility, weight loss via a GLP-1 is often the smarter first move.

If the goal is weight loss and you are weighing your options, our comparisons of semaglutide vs tirzepatide and the full GLP-1 side effects guide cover the broader trade-offs. For men focused on fertility, see our deeper look at GLP-1 effects on fertility in men and women.

Safety notes

Sexual side effects are not the dangerous part of GLP-1 therapy, but they can affect quality of life and adherence. Don't tough out a problem in silence — raise it.
A new, persistent ED can occasionally be an early warning sign of cardiovascular disease, independent of any drug. It is worth a real medical evaluation, not just a Viagra prescription.
Be cautious mixing medications. If you start a PDE5 inhibitor for ED, your prescriber should know your full medication list.
Do not use a GLP-1 off-label as a "testosterone booster." The testosterone gains come from weight loss in men who were low because of obesity. That is a narrow situation, not a general performance hack.

Frequently Asked Questions

Do GLP-1 drugs raise or lower testosterone?

In men with obesity and weight-related low testosterone, GLP-1 drugs tend to raise testosterone, mostly by driving weight loss. A 2025 meta-analysis found a significant rise in bioavailable testosterone. The effect is real but partial — free testosterone barely moved — and it applies mainly to men whose low T was caused by their weight in the first place.

Can Ozempic or Wegovy cause erectile dysfunction?

It can be associated with it. A 2025 database study found non-diabetic men on semaglutide had about 4.5 times the rate of new ED versus matched controls, though the absolute rates were low (roughly 1.5% vs 0.3%). It is an association, not proof of cause. In men with diabetes, GLP-1s may actually improve erections by improving blood flow.

Do GLP-1 medications affect sex drive?

The trial data is quiet, but real-world surveys show effects in both directions. In a Kinsey Institute survey, about 18% of users reported higher desire and 16% reported lower desire. Some people feel more interested as they lose weight and feel better; others report a clear drop. The libido evidence is the weakest of any topic here.

Will my sexual function go back to normal if I stop the drug?

There is no solid controlled data on this. Because the main mechanism is weight loss, effects driven by weight change may persist as long as the weight stays off. Side effects tied to feeling unwell usually fade. Talk to your prescriber before stopping, since abrupt discontinuation has its own downsides like weight regain.

Are the effects different for men and women?

Yes, and women are much less studied. In men there are clearer signals for testosterone and erectile function. In women, most effects appear indirect — through weight loss, hormonal rebalancing, and PCOS improvement — and the data is largely case reports. Treat any sexual change in women as possible but poorly understood.

This article is for general education and is not medical advice. GLP-1 medications are prescription drugs; discuss any sexual side effects, testosterone testing, or treatment changes with a licensed clinician who knows your history.