Does Retatrutide Cause Hair Loss?
No, retatrutide does not cause hair loss based on available clinical trial data. Hair loss has not been reported as an adverse event in any of the phase 2 trials evaluating retatrutide for obesity or type 2 diabetes 1, 2, 3, 4.
Evidence from Clinical Trials
The safety profile of retatrutide has been well-characterized across multiple phase 2 studies involving hundreds of participants:
Gastrointestinal events were the predominant adverse effects, including nausea, diarrhea, vomiting, and constipation, occurring in 13-50% of participants depending on dose 2, 3.
No reports of alopecia or hair loss appeared in the comprehensive safety analyses from trials lasting 24-48 weeks 2, 3, 4.
The most common adverse events were dose-related and mostly mild to moderate in severity 3.
Why This Question May Arise
Confusion about retatrutide and hair loss likely stems from its classification as a GLP-1 receptor agonist (among other mechanisms), a drug class that does not typically cause hair loss:
Other retinoids (not retatrutide) do cause significant hair loss: Acitretin causes alopecia in up to 75% of patients, particularly women at doses exceeding 17.5 mg daily 5, 6.
Isotretinoin causes frank alopecia in less than 10% of patients, with older age and higher cumulative doses being risk factors 6, 7.
Retatrutide is NOT a retinoid despite the similar-sounding name—it is a triple hormone receptor agonist (GIP/GLP-1/glucagon) with an entirely different mechanism of action 5, 1, 2.
Important Distinction
The name "retatrutide" may phonetically resemble "retinoid," but these are completely different drug classes with different mechanisms and side effect profiles. Retinoids (vitamin A derivatives like isotretinoin and acitretin) commonly cause hair loss through effects on hair follicle cycling 5, 6. Retatrutide works through incretin and glucagon pathways to promote weight loss and has not demonstrated hair-related adverse effects in clinical trials 2, 3.