What the product information says
We searched the US labels, the EU product information and the Canadian monographs for erectile dysfunction, libido and sexual dysfunction. The only matches were in the animal studies, where young rats given semaglutide reached sexual maturity later [3][4]. That finding concerns growing animals and is not described as a side effect in adults.
Two label sections are relevant to sexual health even though they are not about sexual function. The tirzepatide label explains that delayed stomach emptying can reduce how well oral hormonal contraceptives work, mostly after the first dose and after dose increases [1]. The labels also say these medicines may harm an unborn baby and should be stopped when pregnancy is recognised [1]. Our separate articles on contraception and pregnancy cover both in more detail.
| Document | Sexual function as a side effect | Related content |
|---|---|---|
| Zepbound®, US label [1] | Not listed | Fatigue 5–7% vs 3%; reduced effect of oral contraceptives; stop when pregnancy is recognised |
| Wegovy®, US label [2] | Not listed | Fatigue 11% vs 5% in adults on 2.4 mg |
| Wegovy®, EU product information [3] | Not listed | Delayed sexual maturation in young rats (animal finding) |
| Wegovy®, Canadian monograph [4] | Not listed | Delayed sexual maturation in young rats (animal finding) |
What studies in men report
The studies disagree, largely because they ask different questions in different groups.
- Health records, young men without diabetes: in the TriNetX database, 3,094 men aged 18 to 50 with obesity who were prescribed semaglutide were matched with the same number who were not. New erectile dysfunction or a new prescription for an erection medicine was recorded in 1.47% against 0.32%, and a new diagnosis of low testosterone in 1.53% against 0.80% [5]. Record studies cannot rule out that men seeking weight treatment also seek other care more often.
- Health records, men with type 2 diabetes: in the same database, tirzepatide was linked to a lower risk of erectile dysfunction than sitagliptin, injectable semaglutide or dulaglutide [7]. The authors said randomised trials are needed.
- Adverse event reports: an analysis of FDA reports from 2003 to 2024 found 182 cases of male sexual dysfunction with GLP-1 medicines and a reporting ratio below one, which the authors read as a weak association [6].
- Randomised trial: 26 healthy men of normal weight took dulaglutide or placebo for four weeks each. Sexual desire, testosterone and sperm measures did not differ [8]. The trial was small and short and did not include people with obesity.
- Meta-analysis: across seven studies of 680 men with overweight or obesity, GLP-1 medicines raised total testosterone, and the rise was larger with more weight loss. Some indexes of erectile function also improved compared with other treatments [9].
What is known for women
A 2026 review of weight-loss medicines and sexual function found promising results in men but described direct evidence in women as limited, and noted case reports suggesting possible sexual side effects with tirzepatide. Across the medicines it examined, sexual outcomes were usually only secondary measures in trials [10].
In practice, the label points that matter most for women are contraception and pregnancy: switching or adding contraception around the start and dose steps of tirzepatide, and stopping treatment when pregnancy is recognised [1].
Why sexual function might change
- Supported by the labels: fatigue is more common than on placebo, and nausea and other stomach effects are frequent in the early weeks [1][2]. Feeling unwell rarely helps desire.
- Supported by research: weight loss is linked to higher testosterone in men with obesity [9], and losing extra weight is one of the lifestyle steps MedlinePlus lists for erection problems [11].
- Proposed but not measured: GLP-1 medicines act on reward pathways in the brain, and animal work raised the idea that they could affect sexual behaviour. The one human trial that tested this found no change in desire [8].
- General: mood, stress, body image and relationship changes all affect sexual function [11][12], and they can shift quickly during noticeable weight loss.
Other causes to consider
MedlinePlus lists common physical causes of erection problems, including diabetes, high blood pressure, heart and thyroid conditions, low testosterone, nerve damage, smoking and alcohol, and medicines such as antidepressants, some blood pressure drugs and sleeping pills [11]. For women, it lists diabetes, heart disease, nerve disorders, hormone problems, some drugs, stress, anxiety, depression and relationship concerns [12].
Many people starting a GLP-1 medicine already have one of these conditions or take one of these drugs. A change in sexual function is a reason to review the full picture, not to assume the newest medicine is responsible.
What may help
MedlinePlus advises seeing a clinician if erection problems happen more than a quarter of the time, and for women, if problems last more than a few months or cause distress [11][12]. It also notes that counselling can help couples who find it hard to talk about sex [11].
Treatments for erection problems exist, but some interact dangerously with other medicines, notably nitrates for chest pain [11]. Any treatment should be chosen with your prescriber, who knows your heart health and medicine list. Do not stop or change a GLP-1 medicine on your own because of sexual side effects.
Wegovy® is a registered trademark of Novo Nordisk A/S. Zepbound® is a registered trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.
When to get help
The signs and contact information below come from this article’s sourced guidance.