Setmelanotide
Setmelanotide (Imcivree)
Setmelanotide (brand name Imcivree) is an FDA-approved cyclic peptide agonist of the melanocortin-4 receptor (MC4R) indicated for chronic weight management in adults and children aged 6 and older with obesity due to POMC, PCSK1, or LEPR deficiency, or Bardet-Biedl syndrome. It is the first pharmacotherapy specifically targeting genetic defects in the MC4R pathway and represents a precision medicine approach to monogenic and syndromic obesity. The drug is administered via subcutaneous injection and has demonstrated significant reductions in body weight and hyperphagia in clinical trials.
Mechanism of Action
Setmelanotide acts as a potent, selective agonist at the melanocortin-4 receptor (MC4R), a G protein-coupled receptor expressed in the hypothalamus that plays a central role in regulating energy homeostasis and satiety. In patients with deficiencies in POMC, PCSK1, or leptin receptor (LEPR), the normal signaling cascade that produces alpha-MSH (which activates MC4R) is disrupted, leading to severe hyperphagia and obesity; setmelanotide bypasses these upstream defects by directly activating MC4R. Activation of MC4R restores downstream signaling through the hypothalamic energy regulation pathway, reducing hunger and increasing satiety, thereby promoting caloric restriction and weight loss.
Evidence by Health Goal(17 goals)
Dosing Protocols
Morning, subcutaneous injection into abdomen, thigh, or upper arm
Titration protocol required: begin at 0.5mg/day for 2 weeks, increase to 1mg/day for 2 weeks, then to 2mg/day. Maximum dose is 3mg/day. Pediatric dosing begins at 0.5mg/day with slower titration. Dose must be individualized based on efficacy and tolerability. Administered as a long-term chronic therapy, not cycled.
Safety & Side Effects
Setmelanotide carries an FDA black box warning for depression and suicidal ideation, requiring monitoring throughout treatment; it is a prescription-only medication in the US and other jurisdictions and is not approved for general obesity management. The drug is generally well-tolerated in the labeled populations but should only be used under specialist supervision with documented genetic or syndromic indications, and is not appropriate for off-label use in common polygenic obesity.
Possible Side Effects
- !Injection site reactions (erythema, discomfort, induration) - most frequently reported adverse event
- !Hyperpigmentation of skin (diffuse or localized) due to MC1R agonism
- !Nausea, especially during dose titration phase
- !Spontaneous penile erections or sexual adverse reactions in males
- !Female sexual dysfunction or spontaneous arousal
- !Depression or suicidal ideation - black box warning requires monitoring
- !Vomiting during titration or dose escalation
- !Hypersensitivity or anaphylaxis reactions (rare)
Interactions
- -Other weight loss agents or anorectic drugs - additive CNS and cardiovascular effects, concurrent use not established
- -Naltrexone or opioid antagonists - may theoretically affect melanocortin pathway signaling, interaction not fully characterized
- -Serotonergic drugs (SSRIs, SNRIs, MAOIs) - caution warranted given overlapping psychiatric side effect profile and potential for exacerbating mood disturbances
- -Antihypertensive agents - weight loss-associated blood pressure reduction may require dose adjustment of antihypertensives
- -QT-prolonging medications - limited data; use caution given lack of robust cardiac interaction studies
Cost & Where to Buy
Imcivree is an extremely high-cost biologic prescription drug; list price exceeds $200,000 annually without insurance. Rhythm Pharmaceuticals offers a patient assistance program for eligible patients. Insurance coverage requires documented genetic testing confirming eligible deficiency. Compounded or research-grade versions are not established and would be outside approved use.
Search on Amazon