Is setmelanotide FDA-approved?

Yes. Setmelanotide is the active ingredient of IMCIVREE, approved by FDA under NDA 213793 with sponsor Rhythm and marketing status 'Prescription' in the Drugs@FDA database. The original application was approved on 25 November 2020 under priority review as a Type 1 New Molecular Entity carrying an orphan submission property, and six supplements follow it in the record, the most recent efficacy supplement approved on 19 March 2026. Drugs@FDA lists exactly one application and one product containing setmelanotide: setmelanotide acetate as a solution for subcutaneous use. Approval is specific to that product and to the indications in its labeling — it is not a general endorsement of the molecule, and there is no approved generic or second brand.

Is Imcivree approved for general weight loss or ordinary obesity?

No. The FDA-approved labeling for IMCIVREE excludes it in its Limitations of Use: IMCIVREE 'is not indicated for the treatment of patients with the following conditions as IMCIVREE would not be expected to be effective: … Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity.' Read the standard the label sets — not that the effect is unproven in these patients, but that it 'would not be expected to be effective', which follows from the mechanism the label describes: setmelanotide is an MC4 receptor agonist and the label frames its effect around obesity 'associated with insufficient activation of the MC4 receptor'. The label also excludes patients whose POMC, PCSK1 or LEPR variants are classified as benign or likely benign, so a genetic test result alone does not establish eligibility.

Does setmelanotide cause skin darkening?

Yes, and the FDA label treats it as an expected pharmacologic effect rather than a rare reaction. The labeling states that 'Generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials', that the effect 'is reversible upon discontinuation of the drug', and that IMCIVREE 'may also cause the development of new melanocytic nevi or darkening of pre-existing nevi due to its pharmacologic effect'. Because of that, the label directs prescribers to 'Perform a full body skin examination prior to initiation and periodically during treatment with IMCIVREE to monitor pre-existing and new skin pigmented lesions.' Skin hyperpigmentation heads the label's list of most common adverse reactions, and in the placebo-controlled period of the Bardet-Biedl syndrome trial the label reports hyperpigmentation disorders in 67% of IMCIVREE-treated patients versus 0% of placebo-treated patients. Note that the label describes setmelanotide as having 20-fold less activity at the melanocortin 1 (MC1) receptor — the pigmentation receptor — than at MC4.

What human evidence supports setmelanotide?

Four Phase 3 registrations, all sponsored by Rhythm Pharmaceuticals, all with results posted, and all of which administered setmelanotide to human participants against a placebo arm. The largest is NCT05774756, a randomized, double-blinded, placebo-controlled trial in acquired hypothalamic obesity with an actual enrolment of 143 and a primary completion date of 18 March 2025; the FDA label reports that after 52 weeks the mean percent change in BMI compared to placebo was -18.40%. The others are NCT03746522 in Bardet-Biedl syndrome (52 enrolled, completed 2021), and NCT02896192 and NCT03287960 in POMC/PCSK1 and LEPR deficiency respectively (15 enrolled each, both completed 2020), which were open-label trials with a double-blind withdrawal period. Two limits are worth stating plainly: the POMC/PCSK1 and LEPR efficacy analyses covered 21 patients between them, and none of these trials studied general obesity — the label states that safety and effectiveness have not been established in otherwise healthy patients with obesity.

What are the risks of setmelanotide?

The FDA label for IMCIVREE carries six Warnings and Precautions and one contraindication. The warnings are: disturbance in sexual arousal, with spontaneous penile erections in males and sexual adverse reactions in females, and an instruction that an erection lasting longer than 4 hours requires emergency medical attention; depression and suicidal ideation, with monitoring directed and discontinuation to be considered; serious hypersensitivity reactions including anaphylaxis, generally occurring within minutes to hours after injection; skin hyperpigmentation, darkening of pre-existing nevi and development of new melanocytic nevi, requiring scheduled full body skin examinations; acute adrenal insufficiency in patients with acquired hypothalamic obesity, reported as a serious adverse reaction in 5% of IMCIVREE-treated patients and no placebo-treated patients in one trial; and sodium imbalance in patients with acquired hypothalamic obesity and central diabetes insipidus. The single contraindication is a prior serious hypersensitivity reaction to setmelanotide or any of the excipients. The label lists the most common adverse reactions, at an incidence of 20% or greater in at least one indication, as skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.

Who is eligible to be prescribed Imcivree?

Per the FDA-approved labeling, IMCIVREE is indicated to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged 4 years and older with acquired hypothalamic obesity, and in adults and pediatric patients aged 2 years and older with syndromic or monogenic obesity due to Bardet-Biedl syndrome, or due to pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1) or leptin receptor (LEPR) deficiency 'confirmed by genetic testing demonstrating variants in POMC, PCSK1, or LEPR genes that are interpreted as pathogenic, likely pathogenic, or of uncertain significance (VUS)'. Three details are routinely dropped in summaries: the age floor differs by condition, the monogenic indications require a confirmatory genetic test rather than a clinical impression, and variants classified as benign or likely benign are expressly excluded by the label's Limitations of Use. Whether an individual patient meets these criteria is a determination for a licensed prescriber.

Setmelanotide

Also sold as: IMCIVREE, Imcivree, Setmelanotide acetate, RM-493, RM 493

Setmelanotide is an FDA-approved melanocortin 4 (MC4) receptor agonist, marketed as IMCIVREE by Rhythm Pharmaceuticals under NDA 213793 and originally approved on 25 November 2020. The approved indication is narrow and diagnosis-gated: the FDA label indicates IMCIVREE to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged 4 years and older with acquired hypothalamic obesity, and aged 2 years and older with Bardet-Biedl syndrome or with POMC, PCSK1 or leptin receptor (LEPR) deficiency confirmed by genetic testing. That same label's Limitations of Use state that IMCIVREE is not indicated for 'Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity', and its Pharmacodynamics section states that the safety and effectiveness of IMCIVREE have not been established in otherwise healthy patients with obesity and that IMCIVREE is not approved to treat such patients. The label carries warnings for disturbance in sexual arousal, depression and suicidal ideation, serious hypersensitivity reactions including anaphylaxis, and generalized skin hyperpigmentation with darkening of pre-existing nevi and development of new melanocytic nevi, for which it directs a full body skin examination before initiation and periodically during treatment.

Which molecule this is. Per the FDA label's Description section, IMCIVREE contains setmelanotide acetate, described as a melanocortin 4 (MC4) receptor agonist and an 8 amino acid cyclic peptide analog of the endogenous melanocortin peptide alpha-MSH (alpha-melanocyte stimulating hormone), molecular formula C49H68N18O9S2 and molecular mass 1117.3 Daltons as the anhydrous free base. The approved product is a subcutaneous solution supplied at 10 mg/mL in a 1 mL multiple-dose vial. Read the receptor selectivity precisely, because it is the axis the wider melanocortin market turns on: the label's Mechanism of Action states setmelanotide is an MC4 receptor agonist 'with 20-fold less activity at the melanocortin 3 (MC3) and melanocortin 1 (MC1) receptors', and notes that MC1 receptors are expressed on melanocytes and that activating them leads to accumulation of melanin and increased skin pigmentation independently of ultraviolet light. Selective is not the same as silent — the pigmentation warning below is on the label of the selective compound.

FDA status

FDA-approved

FDA has approved this as a drug. Approval is always for a specific indication and a specific population — check which one, because it is frequently not the use it is marketed for.

FDA-approved and marketed. Drugs@FDA returns exactly one application for setmelanotide: NDA 213793, sponsor RHYTHM, brand name IMCIVREE, product 001 (setmelanotide acetate, solution, subcutaneous), marketing status 'Prescription'. The original submission was approved 25 November 2020 under priority review as a Type 1 New Molecular Entity, with an orphan submission property. Six supplements follow in the record, three of them efficacy supplements — SUPPL 1 approved 16 June 2022, SUPPL 7 approved 20 December 2024, and SUPPL 9 approved 19 March 2026 — every one of them priority-reviewed and carrying the orphan property. Approval is always for a specific indication and population, and here the population is defined by diagnosis and in part by genetic testing. Read the approval record below before treating this as an approved obesity drug in the general sense.

Drugs@FDA — approved drug products database, queried for setmelanotide (openFDA) — FDA, 31 July 2026Checked against the source on 2 August 2026.

Evidence

Proven in humans

Efficacy established by adequate, well-controlled trials in humans.

Administration check RUN per registration on 2026-08-02, not inferred from the approval. The label names four pivotal trials and all four were opened on ClinicalTrials.gov. Every one lists lead sponsor Rhythm Pharmaceuticals, Inc., phase PHASE3, an intervention of type DRUG named 'Setmelanotide' alongside a DRUG placebo arm, an ACTUAL enrolment count, and hasResults true. Trial 1, NCT05774756 (acquired hypothalamic obesity): enrolment 143 ACTUAL, primary completion 2025-03-18 ACTUAL, status ACTIVE_NOT_RECRUITING. Trial 2, NCT03746522 (Bardet-Biedl syndrome): enrolment 52 ACTUAL, completed 2021-03-08. Trial 3, NCT02896192 (POMC/PCSK1 deficiency): enrolment 15 ACTUAL, completed 2020-05-25. Trial 4, NCT03287960 (LEPR deficiency): enrolment 15 ACTUAL, completed 2020-09-25. Setmelanotide was ADMINISTERED to human participants in each — this is not the endogenous biomarker trap that reduces MOTS-c and TB-500 from an apparent five human RCTs to an actual zero. None of these registrations shows the contamination seen elsewhere in this vertical: no cloned protocol, no recruiting shell, no empty results section. SCOPE, and it is the whole point of the tier being narrow. The tier attaches to the populations studied — acquired hypothalamic obesity, Bardet-Biedl syndrome, and POMC, PCSK1 or LEPR deficiency — and to nothing else. Trials 3 and 4 were open-label with an 8-week double-blind withdrawal period and analysed 21 patients between them; that is adequate for an orphan indication and is not a general obesity evidence base. The label itself states that safety and effectiveness have not been established in otherwise healthy patients with obesity. Evidence does not travel across indications.

A Trial of Setmelanotide in Acquired Hypothalamic Obesity — ClinicalTrials.gov, 18 March 2025

“A Trial of Setmelanotide in Acquired Hypothalamic Obesity”

Checked against the source on 2 August 2026.

What FDA actually approved

Application: NDA 213793 — IMCIVREE
Approved indication: IMCIVREE is indicated to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged: 4 years and older with acquired hypothalamic obesity (HO); 2 years and older with syndromic or monogenic obesity due to: Bardet-Biedl syndrome (BBS); Pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency confirmed by genetic testing demonstrating variants in POMC, PCSK1, or LEPR genes that are interpreted as pathogenic, likely pathogenic, or of uncertain significance (VUS). Limitations of Use: IMCIVREE is not indicated for the treatment of patients with the following conditions as IMCIVREE would not be expected to be effective: Obesity due to suspected POMC, PCSK1, or LEPR deficiency with POMC, PCSK1, or LEPR variants classified as benign or likely benign. Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity.

Recorded verbatim from the current SPL, including the Limitations of Use, because the Limitations are where this record earns its keep. The quote above is reproduced exactly as the label's Highlights section reads, typo included ('obsesity') — it is FDA's document, not ours to tidy. Three things the secondary coverage gets wrong. (1) THIS IS NO LONGER A PURELY GENETIC INDICATION. ACQUIRED hypothalamic obesity — obesity following injury to or dysfunction of the hypothalamus — was added by efficacy supplement 9, approved 19 March 2026 per Drugs@FDA, and the SPL's own Recent Major Changes block stamps Indications and Usage 03/2026. Descriptions of IMCIVREE as a genetic-obesity-only drug are now incomplete. (2) The qualifying age floors DIFFER by condition — 4 years and older for acquired HO, 2 years and older for the syndromic and monogenic indications — and the label's own Clinical Studies section still describes the BBS and POMC/PCSK1/LEPR trials as conducted in patients aged 6 years and older, with a separate trial in patients aged 2 to less than 6 years. Age eligibility and the age range studied in the pivotal trials are not the same number. (3) The genetic gate admits variants 'of uncertain significance (VUS)' and expressly excludes variants classified as benign or likely benign. A genetic test result is not a binary key to this drug. discontinued is false as a live check, not an assumption: Drugs@FDA shows the single product under NDA 213793 with marketing status 'Prescription'.

IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026

“IMCIVREE is a melanocortin 4 (MC4) receptor agonist indicated to reduce excess body weight and maintain reduction long term in adults and pediatric patients aged (1): 4 years and older with acquired hypothalamic obsesity (HO). 2 years and older with Bardet-Biedl syndrome (BBS). 2 years and older with pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency …”

Checked against the source on 2 August 2026.

What FDA found

FDA’s own words. These are the most citable thing on this site, and the least likely to appear anywhere funded by someone selling the compound.

The FDA-approved labeling for IMCIVREE states that it is not indicated for other types of obesity not related to acquired hypothalamic obesity, Bardet-Biedl syndrome, or POMC, PCSK1 or LEPR deficiency — including obesity associated with other genetic syndromes and general (polygenic) obesity — as it would not be expected to be effective.
The single most load-bearing sentence on this record. Note the wording of the exclusion: it is not a caution about unknown effects, it is a statement that the drug 'would not be expected to be effective' in these patients. The mechanism section explains why — the label describes setmelanotide as potentially re-establishing MC4 receptor pathway activity in patients whose obesity is 'associated with insufficient activation of the MC4 receptor'. Where that pathway defect is not the cause, the label does not expect the mechanism to apply. An MC4R agonist is not a general weight-loss drug on this label.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Limitations of Use: IMCIVREE is not indicated for the treatment of patients with the following conditions as IMCIVREE would not be expected to be effective: • Obesity due to suspected POMC, PCSK1, or LEPR deficiency with POMC, PCSK1, or LEPR variants classified as benign or likely benign. • Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity.”
Checked against the source on 2 August 2026.
The label's Pharmacodynamics section reports that short-term administration of IMCIVREE in 12 otherwise healthy patients with obesity increased resting energy expenditure and shifted substrate oxidation to fat, and states in the same paragraph that the safety and effectiveness of IMCIVREE have not been established in such patients and that IMCIVREE is not approved to treat such patients.
An FDA label pre-emptively disclaiming the adjacent market, in one paragraph, on the same page as the finding that market would quote. The metabolic result is real and it is on the label; the sentence immediately after it is the reason the result cannot be carried into a general obesity or body-composition claim. Anyone citing the energy expenditure finding without the following sentence is quoting half of a two-sentence paragraph, and the half FDA wrote second is the one that scopes the first.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Short-term administration of IMCIVREE in 12 otherwise healthy patients with obesity increased resting energy expenditure and shifted substrate oxidation to fat. The safety and effectiveness of IMCIVREE have not been established in such patients and IMCIVREE is not approved to treat such patients.”
Checked against the source on 2 August 2026.
Drugs@FDA records a single approved application containing setmelanotide — NDA 213793, sponsor RHYTHM, brand name IMCIVREE — originally approved 25 November 2020 under priority review as a Type 1 New Molecular Entity with an orphan submission property, with the most recent efficacy supplement (SUPPL 9) approved 19 March 2026.
Queried live on 2026-08-02 against openFDA `drug/drugsfda`, meta.last_updated 2026-07-31. One application, one product: product 001, active ingredient SETMELANOTIDE ACETATE, dosage form SOLUTION, route SUBCUTANEOUS, marketing status 'Prescription', reference drug Yes. There is no second sponsor, no generic, and no second brand. The full submission history in the record is: ORIG 1 approved 2020-11-25; SUPPL 1 (Efficacy) 2022-06-16; SUPPL 5 (Labeling) 2023-11-15; SUPPL 7 (Efficacy) 2024-12-20; SUPPL 8 (Labeling) 2025-08-21; SUPPL 9 (Efficacy) 2026-03-19. What each supplement CHANGED is not stated in this database and is not asserted here — the dates and classes are what the record carries. The acquired hypothalamic obesity indication is tied to the March 2026 supplement by the label's own Recent Major Changes stamp, not by this source alone.
Drugs@FDA — approved drug products database, queried for setmelanotide (openFDA) — FDA, 31 July 2026Checked against the source on 2 August 2026.
The FDA-approved labeling directs that a full body skin examination be performed prior to initiation and periodically during treatment with IMCIVREE, to monitor pre-existing and new pigmented skin lesions.
Recorded as a regulatory finding as well as a safety signal because of what it implies about supervision. FDA did not respond to the pigmentation effect with a warning to read; it responded with a scheduled clinical procedure, before initiation and repeatedly during treatment. That is a monitoring requirement that only exists inside a prescribing relationship. Note also that the label attributes the new and darkening nevi to the drug's 'pharmacologic effect' — this is the mechanism operating, not an idiosyncratic reaction, and it is on the label of the MC1-SELECTIVE compound in this class.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials … IMCIVREE may also cause the development of new melanocytic nevi or darkening of pre-existing nevi due to its pharmacologic effect. Perform a full body skin examination prior to initiation and periodically during treatment with IMCIVREE to monitor pre-existing and new skin pigmented lesions.”
Checked against the source on 2 August 2026.

Documented safety signals

Warning — Disturbance in Sexual Arousal. Per the label, spontaneous penile erections and increased frequency of penile erections in males occurred in clinical trials with IMCIVREE, and sexual adverse reactions in females have occurred. The label instructs patients who have an erection lasting longer than 4 hours to seek emergency medical attention.
A melanocortin class effect appearing on the label of an agonist selected for MC4 activity. In the acquired hypothalamic obesity trial the label reports spontaneous or increased-frequency penile erections in 7% of IMCIVREE-treated patients versus 4% of placebo-treated patients, and in the trial of patients aged 2 to less than 6 years, spontaneous penile erections in 8% of IMCIVREE-treated patients. Recorded plainly because it is listed among the most common adverse reactions on a paediatric label, which is a different thing from a marketed benefit.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Disturbance in Sexual Arousal: Spontaneous penile erections in males and sexual adverse reactions in females have occurred. Inform patients that these events may occur and instruct patients who have an erection lasting longer than 4 hours to seek emergency medical attention.”
Checked against the source on 2 August 2026.
Warning — Depression and Suicidal Ideation. Per the label, depression and suicidal ideation have occurred; the label directs monitoring for new onset or worsening depression or suicidal thoughts or behaviors, and states that discontinuing IMCIVREE should be considered if patients experience suicidal thoughts or behaviors or if clinically significant or persistent depression symptoms occur.
Depression appears in the label's list of most common adverse reactions at an incidence of 20% or greater in at least one indication. The label also reports depressed mood in 8% of IMCIVREE-treated patients in the trial of patients aged 2 to less than 6 years. This is a centrally acting drug and the label says so in the warning itself.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Some drugs that target the central nervous system, such as IMCIVREE, may cause depression or suicidal ideation … Patients with a history of depression or suicidal ideation may be at increased risk for recurrent episodes while taking IMCIVREE.”
Checked against the source on 2 August 2026.
Warning and contraindication — serious hypersensitivity reactions, including anaphylaxis, have been reported with IMCIVREE, generally occurring within minutes to hours after injection. IMCIVREE is contraindicated in patients with a prior serious hypersensitivity reaction to setmelanotide or any of its excipients. Hypersensitivity including anaphylaxis also appears in the label's Postmarketing Experience section.
The only contraindication on this label, and it is a screening question that requires someone to ask it. Worth reading alongside the label's Description section, which lists the excipients — benzyl alcohol, carboxymethylcellulose sodium, edetate disodium dihydrate, a PEGylated phospholipid, mannitol and phenol among them. The contraindication reaches a prior serious reaction to the excipients, not only to setmelanotide itself.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Serious hypersensitivity reactions, including anaphylaxis, have been reported with IMCIVREE. These reactions generally occurred within minutes to hours after injecting IMCIVREE … IMCIVREE is contraindicated in patients with a prior serious hypersensitivity reaction to setmelanotide or any of the excipients in IMCIVREE.”
Checked against the source on 2 August 2026.
Warning — Skin Hyperpigmentation, Darkening of Pre-Existing Nevi, and Development of New Melanocytic Nevi. Per the label, generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials, an effect the label states is reversible on discontinuation, and IMCIVREE may also cause the development of new melanocytic nevi or darkening of pre-existing nevi.
The frequency is the part that gets lost: the majority of treated patients, not a minority. In the placebo-controlled period of the Bardet-Biedl syndrome trial the label reports hyperpigmentation disorders in 67% of IMCIVREE-treated patients versus 0% of placebo-treated patients. Skin hyperpigmentation heads the label's list of most common adverse reactions. Read this against the Mechanism of Action, which states setmelanotide has 20-fold LESS activity at MC1 than at MC4 — the selective compound still produced this in most patients, and FDA still required scheduled full body skin examinations.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials … This effect is reversible upon discontinuation of the drug. IMCIVREE may also cause the development of new melanocytic nevi or darkening of pre-existing nevi due to its pharmacologic effect.”
Checked against the source on 2 August 2026.
Warning — Acute Adrenal Insufficiency in patients with acquired hypothalamic obesity. In a clinical trial of adults and pediatric patients aged 4 years and older with acquired HO and secondary adrenal insufficiency, the label reports that serious adverse reactions related to acute adrenal insufficiency were reported by 5% of IMCIVREE-treated patients and no placebo-treated patients.
New in March 2026 — this warning (section 5.5) and the sodium warning (5.6) are both stamped 03/2026 in the label's Recent Major Changes block, arriving with the acquired hypothalamic obesity indication. The expansion of an approval is not only an expansion of who may be treated; here it added two warnings that did not previously exist, both specific to the newly indicated population, both concerning serious endocrine events, and both separating from placebo in the trial that supported the expansion.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“In a clinical trial of adults and pediatric patients aged 4 years and older with acquired HO and secondary adrenal insufficiency, serious adverse reactions related to acute adrenal insufficiency were reported by 5% of IMCIVREE-treated patients and no placebo-treated patients. In patients with secondary adrenal insufficiency, monitor for clinical signs of acute adrenal insufficiency.”
Checked against the source on 2 August 2026.
Warning — Sodium Imbalance in patients with acquired hypothalamic obesity and central diabetes insipidus. In a clinical trial of adults and pediatric patients aged 4 years and older with acquired HO and concomitant central diabetes insipidus / arginine vasopressin deficiency, the label reports hyponatremia in 6% of IMCIVREE-treated patients versus 2% of placebo-treated patients, and hypernatremia in 5% of IMCIVREE-treated patients versus 4% of placebo-treated patients.
Read the two directions separately. Hyponatremia separated from placebo by a factor of three in the label's reported percentages; hypernatremia barely separated at all. Flattening both into 'sodium problems' loses the asymmetry. The label's response is serum sodium monitoring tied to changes in fluid intake and hydration status — again, laboratory monitoring inside a prescribing relationship rather than a caution to read.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“hyponatremia was reported in 6% of IMCIVREE-treated patients and 2% of placebo-treated patients, and hypernatremia was reported in 5% of IMCIVREE-treated patients and 4% of placebo-treated patients. In patients with acquired HO and concomitant DI/AVP deficiency, monitor serum sodium levels with changes in fluid intake and hydration status.”
Checked against the source on 2 August 2026.
Per the label, the most common adverse reactions at an incidence of 20% or greater in at least one indication were skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.
Reproduced in full because two entries on this list — depression and spontaneous penile erection — are the kind of adverse reaction that gets marketed as a feature elsewhere in the melanocortin market, and they are here at an incidence of 20% or greater in at least one indication, on a label that also covers children. The 20% threshold is FDA's, not ours, and the label does not break the figure out by reaction in this summary.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Most common adverse reactions (incidence ≥20% in at least 1 indication) included skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.”
Checked against the source on 2 August 2026.

Questions people actually ask

Every answer cites the document behind it. Where the honest answer is “nobody knows”, that is the answer you will get.

Is setmelanotide FDA-approved?: Yes. Setmelanotide is the active ingredient of IMCIVREE, approved by FDA under NDA 213793 with sponsor Rhythm and marketing status 'Prescription' in the Drugs@FDA database. The original application was approved on 25 November 2020 under priority review as a Type 1 New Molecular Entity carrying an orphan submission property, and six supplements follow it in the record, the most recent efficacy supplement approved on 19 March 2026. Drugs@FDA lists exactly one application and one product containing setmelanotide: setmelanotide acetate as a solution for subcutaneous use. Approval is specific to that product and to the indications in its labeling — it is not a general endorsement of the molecule, and there is no approved generic or second brand.
Drugs@FDA — approved drug products database, queried for setmelanotide (openFDA) — FDA, 31 July 2026Checked against the source on 2 August 2026.
Is Imcivree approved for general weight loss or ordinary obesity?: No. The FDA-approved labeling for IMCIVREE excludes it in its Limitations of Use: IMCIVREE 'is not indicated for the treatment of patients with the following conditions as IMCIVREE would not be expected to be effective: … Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity.' Read the standard the label sets — not that the effect is unproven in these patients, but that it 'would not be expected to be effective', which follows from the mechanism the label describes: setmelanotide is an MC4 receptor agonist and the label frames its effect around obesity 'associated with insufficient activation of the MC4 receptor'. The label also excludes patients whose POMC, PCSK1 or LEPR variants are classified as benign or likely benign, so a genetic test result alone does not establish eligibility.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Limitations of Use: IMCIVREE is not indicated for the treatment of patients with the following conditions as IMCIVREE would not be expected to be effective: • Obesity due to suspected POMC, PCSK1, or LEPR deficiency with POMC, PCSK1, or LEPR variants classified as benign or likely benign. • Other types of obesity not related to acquired HO, BBS, or POMC, PCSK1, or LEPR deficiency, including obesity associated with other genetic syndromes and general (polygenic) obesity.”
Checked against the source on 2 August 2026.
Does setmelanotide cause skin darkening?: Yes, and the FDA label treats it as an expected pharmacologic effect rather than a rare reaction. The labeling states that 'Generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials', that the effect 'is reversible upon discontinuation of the drug', and that IMCIVREE 'may also cause the development of new melanocytic nevi or darkening of pre-existing nevi due to its pharmacologic effect'. Because of that, the label directs prescribers to 'Perform a full body skin examination prior to initiation and periodically during treatment with IMCIVREE to monitor pre-existing and new skin pigmented lesions.' Skin hyperpigmentation heads the label's list of most common adverse reactions, and in the placebo-controlled period of the Bardet-Biedl syndrome trial the label reports hyperpigmentation disorders in 67% of IMCIVREE-treated patients versus 0% of placebo-treated patients. Note that the label describes setmelanotide as having 20-fold less activity at the melanocortin 1 (MC1) receptor — the pigmentation receptor — than at MC4.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Generalized or focal increases in skin pigmentation occurred in the majority of IMCIVREE-treated patients in clinical trials … Perform a full body skin examination prior to initiation and periodically during treatment with IMCIVREE to monitor pre-existing and new skin pigmented lesions.”
Checked against the source on 2 August 2026.
What human evidence supports setmelanotide?: Four Phase 3 registrations, all sponsored by Rhythm Pharmaceuticals, all with results posted, and all of which administered setmelanotide to human participants against a placebo arm. The largest is NCT05774756, a randomized, double-blinded, placebo-controlled trial in acquired hypothalamic obesity with an actual enrolment of 143 and a primary completion date of 18 March 2025; the FDA label reports that after 52 weeks the mean percent change in BMI compared to placebo was -18.40%. The others are NCT03746522 in Bardet-Biedl syndrome (52 enrolled, completed 2021), and NCT02896192 and NCT03287960 in POMC/PCSK1 and LEPR deficiency respectively (15 enrolled each, both completed 2020), which were open-label trials with a double-blind withdrawal period. Two limits are worth stating plainly: the POMC/PCSK1 and LEPR efficacy analyses covered 21 patients between them, and none of these trials studied general obesity — the label states that safety and effectiveness have not been established in otherwise healthy patients with obesity.
A Trial of Setmelanotide in Acquired Hypothalamic Obesity — ClinicalTrials.gov, 18 March 2025
“A Trial of Setmelanotide in Acquired Hypothalamic Obesity”
Checked against the source on 2 August 2026.
Was Imcivree's approval expanded in 2026?: Yes. Drugs@FDA records an efficacy supplement to NDA 213793 (SUPPL 9) approved on 19 March 2026 under priority review with an orphan submission property, and the current Structured Product Label's Recent Major Changes block stamps Indications and Usage 03/2026 together with two new Warnings and Precautions subsections, 5.5 and 5.6. The current label indicates IMCIVREE for adults and pediatric patients aged 4 years and older with acquired hypothalamic obesity — obesity following injury to or dysfunction of the hypothalamus — alongside the pre-existing syndromic and monogenic indications. This matters for how the drug is described: acquired hypothalamic obesity is not a genetic condition, so summaries calling IMCIVREE a genetic-obesity-only therapy are now out of date. The two new warnings arrived with it and are specific to that population: acute adrenal insufficiency, and sodium imbalance in patients with concomitant central diabetes insipidus.
Drugs@FDA — approved drug products database, queried for setmelanotide (openFDA) — FDA, 31 July 2026Checked against the source on 2 August 2026.
What are the risks of setmelanotide?: The FDA label for IMCIVREE carries six Warnings and Precautions and one contraindication. The warnings are: disturbance in sexual arousal, with spontaneous penile erections in males and sexual adverse reactions in females, and an instruction that an erection lasting longer than 4 hours requires emergency medical attention; depression and suicidal ideation, with monitoring directed and discontinuation to be considered; serious hypersensitivity reactions including anaphylaxis, generally occurring within minutes to hours after injection; skin hyperpigmentation, darkening of pre-existing nevi and development of new melanocytic nevi, requiring scheduled full body skin examinations; acute adrenal insufficiency in patients with acquired hypothalamic obesity, reported as a serious adverse reaction in 5% of IMCIVREE-treated patients and no placebo-treated patients in one trial; and sodium imbalance in patients with acquired hypothalamic obesity and central diabetes insipidus. The single contraindication is a prior serious hypersensitivity reaction to setmelanotide or any of the excipients. The label lists the most common adverse reactions, at an incidence of 20% or greater in at least one indication, as skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“Most common adverse reactions (incidence ≥20% in at least 1 indication) included skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.”
Checked against the source on 2 August 2026.
Who is eligible to be prescribed Imcivree?: Per the FDA-approved labeling, IMCIVREE is indicated to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged 4 years and older with acquired hypothalamic obesity, and in adults and pediatric patients aged 2 years and older with syndromic or monogenic obesity due to Bardet-Biedl syndrome, or due to pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1) or leptin receptor (LEPR) deficiency 'confirmed by genetic testing demonstrating variants in POMC, PCSK1, or LEPR genes that are interpreted as pathogenic, likely pathogenic, or of uncertain significance (VUS)'. Three details are routinely dropped in summaries: the age floor differs by condition, the monogenic indications require a confirmatory genetic test rather than a clinical impression, and variants classified as benign or likely benign are expressly excluded by the label's Limitations of Use. Whether an individual patient meets these criteria is a determination for a licensed prescriber.
IMCIVREE (setmelanotide) injection, solution — Prescribing Information (current SPL) — DailyMed (U.S. National Library of Medicine), 1 April 2026
“IMCIVREE is indicated to reduce excess body weight and maintain weight reduction long term in adults and pediatric patients aged … : 4 years and older with acquired hypothalamic obesity (HO) … 2 years and older with syndromic or monogenic obesity due to: o Bardet-Biedl syndrome (BBS) o Pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency confirmed by genetic testing …”
Checked against the source on 2 August 2026.