Do GLP-1 medicines affect libido or relationships? What the evidence shows

What the source reports

The most direct controlled human evidence comes from a small Phase 2 crossover study of dulaglutide. Twenty-six healthy men aged 18 to 50 were randomly assigned to receive dulaglutide and placebo for four weeks each, separated by a washout period; 24 participants completed the study.

Researchers found no statistically significant difference between dulaglutide and placebo in a questionnaire covering sexual interest, arousal, orgasm, erection and overall sexual satisfaction. They also reported no significant treatment differences in reproductive hormones or conventional sperm measurements.

The result is reassuring within that narrow study population, but it cannot answer the broader question on its own. The trial involved healthy, normal-weight men with satisfactory sex lives, lasted only four weeks per treatment period and studied dulaglutide rather than every medicine in the wider GLP-1 category.

What adverse-event reports can—and cannot—show

A separate 2025 study examined the US Food and Drug Administration Adverse Event Reporting System. It identified 182 reports of male sexual dysfunction associated with GLP-1 receptor agonists between late 2003 and early 2024, including reports concerning erectile function, orgasm and reduced libido.

The study's disproportionality measures indicated a weak association rather than a strong safety signal. The authors said the findings supported continued monitoring as use expands, while describing the overall patient risk as low.

FAERS is designed to help detect possible safety signals, not to prove cause and effect. Reports can be incomplete, duplicated or influenced by publicity, underlying illness and other medicines. The FDA says FAERS data cannot establish how often an event occurs or whether a medicine caused it.

Why individual experiences may point in different directions

Sexual desire and function can be influenced by metabolic health, body image, confidence, hormones, gastrointestinal symptoms, mood, age, relationship circumstances and other medicines. Weight loss itself may change several of these factors at the same time.

Research on GLP-1 medicines and reward-related brain responses has prompted hypotheses about effects beyond appetite. However, a biological hypothesis is not evidence that a medicine changes romantic attachment, and evidence from food, alcohol or animal studies cannot be assumed to apply to human relationships.

A 2026 review of studies in women and men concluded that human findings on libido and sexual function remain limited and heterogeneous, with possible differences by sex, metabolic health, medicine and psychosocial context.

What the evidence says about relationships

There is currently no controlled clinical evidence showing that GLP-1 medicines cause relationship breakdown or make people fall out of love. Personal accounts and surveys can identify experiences worth studying, but they cannot separate a medicine's effects from weight change, health improvements, stigma, confidence or pre-existing relationship dynamics.

This distinction matters because a compelling personal story can be real without establishing a general drug effect. Relationship outcomes are complex, and the available medicine studies were not designed to measure them.

What remains uncertain

Longer studies are needed in the people who commonly receive these medicines, including women, older adults and people living with obesity or diabetes. Research also needs to distinguish between different medicines, doses, treatment durations and changes caused indirectly by weight loss.

Future trials would need validated measures of libido, sexual function, mood and quality of life collected before and during treatment. Relationship effects would require a separate research design and careful consideration of both partners' experiences.

For now, the evidence does not support a simple claim that GLP-1 medicines either increase or suppress desire for everyone. It supports a more cautious conclusion: experiences may vary, while direct causal evidence remains limited.