What the Saxenda® documents contain
None of the three regulators lists a sexual side effect for Saxenda®. [1][2][3] The reproductive findings that do appear come from animal studies or from the teenage trial, and the rest of the relevant entries are general effects that can make sex less appealing.
| Entry | Saxenda® | Placebo | Source |
|---|---|---|---|
| Erectile, libido or orgasm problems | Not listed | — | All three documents [1][2][3] |
| Nausea, adults | 39.3% | 13.8% | US Table 2 [1] |
| Fatigue, adults | 7.5% | 4.6% | US Table 2 [1] |
| Anxiety, adults | 2% | 1.6% | US Table 2 [1] |
| Depression, ages 12–17 | 4% | 2.4% | US Table 3 [1] |
| Low blood pressure reactions, adults | 1.1% | 0.5% | US label 6.1 [1] |
| Growth and pubertal development, ages 12–17 | No effect found | — | EU 4.8; Canadian 8.2.1 [2][3] |
| Male fertility in rats | No direct effect | — | US label 13.1 [1] |
| Sexual maturation in young rats | Delayed, no effect on fertility | — | EU 5.3; Canadian 16 [2][3] |
Studies in men
The clearest liraglutide data come from men with obesity whose testosterone was low because of their weight. In a 16-week randomised open-label study, 30 such men took either liraglutide 3 mg daily or testosterone gel. Testosterone rose in both groups and sexual function improved; the liraglutide group also lost about 8 kg on average and its pituitary hormones LH and FSH rose, while men on the gel lost almost no weight. [4] A second, non-randomised study in 110 young men with the same condition gave liraglutide 3 mg to those not trying for a child; after four months their erectile function was better than at the start, and their testosterone was higher than in the comparison groups. [5]
Pooling seven small studies in 237 men across several GLP-1 medicines, a 2026 meta-analysis found improved erectile function scores and higher total testosterone. [6] A 2026 systematic review of ten studies reached a similar view on testosterone, while noting that free testosterone changes were inconsistent. [7] On the other side, an analysis of US adverse event reports from 2003 to 2024 found 182 reports of male sexual problems with GLP-1 medicines and judged the association weak. [8] All of these studies are small, short or unable to prove cause, and none was a Saxenda® registration trial.
What is known for women
A PubMed search on 20-10-2026 found no human trial reporting sexual function in women on liraglutide. A 2025 case report described a woman who could no longer reach orgasm after starting a GLP-1 medicine; its abstract does not say which one, and a single case cannot show cause. [13] A 2026 study in sexually experienced female mice found that liraglutide reduced time spent with a male, an animal behaviour finding that cannot be translated to people. [9] In young rats, the Canadian monograph adds slightly longer oestrous cycles and slightly smaller litters at the highest dose, the cycles recovered after treatment, and a link between the smaller litters and treatment could not be ruled out. [3]
What is better established is pregnancy advice. Saxenda® should be stopped once a pregnancy is recognised in the US label, and the EU and Canadian documents say it should not be used in pregnancy and should be stopped if someone wishes to become pregnant. [1][2][3] In the Canadian trials, 9 of 31 pregnancies on Saxenda® ended in miscarriage, against 2 of 15 on placebo. [3] Questions about contraception belong with your prescriber.
Indirect ways Saxenda® can get in the way
- Feeling sick: nausea affects more than a third of adults, mostly in the first weeks of the daily dose increases, and is hard to combine with desire. [1][2]
- Tiredness and weakness: fatigue and asthenia are both listed above placebo, mostly in the first 12 weeks. [1]
- Mood: anxiety is listed for adults and depression for teenagers. MedlinePlus counts loss of interest among the core signs of depression. [1][12]
- Low blood sugar in diabetes: risk rises with insulin or a sulfonylurea, and the label lists anxiety, weakness and shakiness among its signs. [1]
- Diabetes itself: about one in seven adults in the trials had type 2 diabetes, which MedlinePlus lists among the physical causes of erection problems and of sexual problems in women. [1][10][11]
Other common causes
MedlinePlus explains that most erection problems have a physical cause: diabetes, high blood pressure, heart or thyroid conditions, clogged arteries, nerve disorders, low testosterone, nerve damage after prostate surgery, and nicotine, alcohol or drug use. [10] Many medicines contribute, including antidepressants, beta blockers and other blood pressure drugs, digoxin, sleeping pills and some ulcer medicines. [10] Stress, anxiety, relationship strain and fear of failure play a part, more often in younger men. [10]
For women, MedlinePlus lists lack of desire, problems with arousal or orgasm, and painful sex, with physical causes such as diabetes, heart disease, nerve disorders and hormone problems, as well as medicines, stress, depression and relationship concerns. [11] Occasional problems are common; problems that last more than a few months or cause distress are worth raising. [11]
What helps
MedlinePlus suggests not smoking, limiting alcohol, avoiding illegal drugs, sleeping enough, keeping a healthy weight, staying active, keeping blood sugar under control in diabetes and talking openly with your partner, with counselling if communication is hard. [10] If you suspect a medicine, it advises talking to your provider and not stopping or changing anything on your own. [10]
Saxenda® asks you to give your provider a full list of your medicines, which helps when several could be playing a part. [1] Nausea and fatigue tend to ease after the first weeks, so a change that began during the dose increases may settle; a change that persists is worth discussing, since diabetes, blood pressure treatment and mood can all be checked. [1][2]
Saxenda® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.
When to get help
The signs and contact information below come from this article’s sourced guidance.