Mounjaro and Decreased Libido
Mounjaro (tirzepatide) is not documented to cause decreased libido based on available clinical evidence and guidelines. There is no established association between tirzepatide and sexual dysfunction in the medical literature.
Evidence Review
Lack of Sexual Side Effects with GLP-1/GIP Agonists
- Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist used for type 2 diabetes and weight management 1, 2
- The most common adverse events with tirzepatide are gastrointestinal, including nausea, diarrhea, decreased appetite, and vomiting—not sexual dysfunction 1
- Sexual side effects are not listed among the known adverse effects of tirzepatide in comprehensive drug reviews 3, 1, 2
- Major clinical trials (SURPASS program) evaluating tirzepatide did not identify decreased libido as a significant adverse event 1, 2
Medications That Actually Cause Decreased Libido
For context, medications with well-documented effects on libido include:
- SSRIs cause decreased libido, orgasmic dysfunction, and erectile problems, with sexual dysfunction rates likely underreported in clinical trials 4
- Paroxetine has the highest rates of sexual dysfunction among antidepressants 4
- Alpha-1 blockers used for lower urinary tract symptoms do not affect libido, though they cause ejaculatory dysfunction 5
- 5-alpha reductase inhibitors (finasteride, dutasteride) cause reduced libido, erectile dysfunction, and ejaculation disorders 5
- Beta-blockers and mineralocorticoid receptor antagonists can negatively affect libido and erectile function 5
- HMG-CoA reductase inhibitors (statins) may cause decreased libido, possibly through lowered testosterone levels 6
Alternative Explanations to Consider
If a patient on Mounjaro reports decreased libido, evaluate:
- Underlying chronic illness and hormonal abnormalities associated with obesity, diabetes, or liver disease can independently cause decreased libido 5
- Psychogenic causes, alcohol use, and other medications should be systematically evaluated 5
- Hypogonadism, hyperprolactinemia, and psychopathology are common causes of secondary reduced libido 7
- Relationship disturbances and psychosocial factors characterize primary reduced libido 7
Clinical Approach
When a patient on tirzepatide reports decreased libido, look beyond the medication:
- Obtain testosterone levels and thyroid function tests 5
- Screen for depression, anxiety, and relationship issues 7
- Review all concurrent medications, particularly antihypertensives, antidepressants, and statins 5, 4
- Assess for uncontrolled diabetes, cardiovascular disease, and metabolic syndrome as independent contributors 5
- Consider referral to appropriate specialists (endocrinology, urology, psychiatry) for comprehensive evaluation 5
The temporal association with starting Mounjaro is likely coincidental rather than causal, given the complete absence of this adverse effect in clinical trials and post-marketing surveillance data 1, 2.