Class 11 · Dermatologic · melanocortin-1 (MC1R) agonist · α-MSH analog · FDA-approved implant · restricted indication
Melanotan IAfamelanotide · NDP-α-MSH · Scenesse — the photoprotection implant, not a tanning shot
Melanotan I — properly afamelanotide — is a prescription medicine that mimics α-MSH, the hormone that tells skin to make its dark, protective pigment (eumelanin). It is FDA-approved as a small under-the-skin implant (Scenesse) to increase pain-free sunlight exposure in adults with a rare genetic disorder called erythropoietic protoporphyria (EPP). It is not a cosmetic tanning drug. Injectable "Melanotan" sold online is unregulated, often chemically unlike afamelanotide, and is a blocked use case here.
Afamelanotide is a synthetic α-MSH analog and melanocortin-receptor agonist that binds predominantly to MC1R, increasing eumelanin and photoprotection. It is delivered as a 16 mg bioresorbable subcutaneous implant placed every 2 months by a trained clinician — not as a self-injected dose. Its only validated indication is EPP, where it increased pain-free light exposure in the pivotal CUV029/CUV039 phase-3 trials. It is symptomatic: protoporphyrin IX levels are unchanged and it does not protect against PPIX-mediated liver damage.
Afamelanotide ([Nle⁴,D-Phe⁷]-α-MSH; C₇₈H₁₁₁N₂₁O₁₉, MW 1646.87, CAS 75921-69-6, CID 16154396) is a tridecapeptide whose Met⁴→Nle and Phe⁷→D-Phe substitutions confer protease resistance and ~100× the melanogenic potency of native α-MSH. It activates MC1R → Gs → cAMP → MITF → tyrosinase, driving eumelanin synthesis, with additional antioxidant, DNA-repair-enhancing, and anti-inflammatory actions. The free peptide's ~30-minute half-life is precisely why it is formulated as a sustained-release implant rather than an injection.
13 aaα-MSH analog · Nle⁴, D-Phe⁷
16 mgImplant · every 2 months SC
~100×Melanogenic potency vs α-MSH
2019FDA approval · Scenesse (EU 2014)
Status
FDA-approved implant · EPP only · cosmetic use blocked
RESTRICTED INDICATION · cosmetic tanning use is BLOCKED
Afamelanotide (Scenesse) is approved only to increase pain-free light exposure in adults with EPP, and only as a clinician-administered subcutaneous implant. There is no approved injectable or cosmetic form; products sold online as "Melanotan" are unregulated and frequently bear no resemblance to afamelanotide. This page is educational only and does not support cosmetic dosing, injection cycles, "loading" protocols, or tanning-protocol calculation.
01 · At a glance
A photoprotection drug, not a tanning peptide.
Afamelanotide is one of the clearest cases in this atlas of a compound whose street reputation diverges from its medical reality. As Scenesse, it is an FDA-approved implant for a rare, painful light-sensitivity disease. As "Melanotan I" online, it is conflated with illicit tanning injections — a use that is unapproved, unstudied, and blocked here. The two should never be confused, and the cyclic relative Melanotan II is a different and riskier molecule entirely.
🩺
Approved use
EPP only
FDA-approved to increase pain-free light exposure in adults with erythropoietic protoporphyria. Grade A.
🔑
Mechanism
MC1R agonist
Activates MC1R → cAMP → MITF → eumelanin synthesis for photoprotection. Grade A.
💉
Delivery
Implant only
A 16 mg bioresorbable implant placed SC every 2 months by a trained clinician. No self-injection. Grade A.
⛔
Cosmetic use
Blocked
Tanning/injection use is unapproved, unregulated, and explicitly blocked. Grade D.
🧬
Structure
[Nle⁴,D-Phe⁷]-α-MSH
A 13-aa α-MSH analog, ~100× more melanogenic and protease-resistant. Grade A.
⚠️
Not Melanotan II
Different drug
MT-II is a cyclic, broad MC3/4R peptide — unapproved, with CNS/sexual effects and melanoma concern. Grade A.
🛡️
Beyond pigment
Antioxidant · DNA repair
Also exerts antioxidant, DNA-repair, and anti-inflammatory effects in skin. Grade B.
📈
Evidence
Phase-3 RCTs
Pivotal CUV029/CUV039 trials (Langendonk 2015) underpin approval. Grade A.
02 · Mechanism of action
Turning up the skin's own protective pigment.
Afamelanotide is a more durable, more potent copy of α-MSH, the natural signal that drives melanocytes to make eumelanin — the dark, photoprotective form of melanin. By engaging MC1R for far longer than the native hormone, it shifts pigment production toward eumelanin and layers on antioxidant and DNA-repair effects, raising the skin's tolerance to light in EPP patients.
Grade A
🔑
1 · MC1R agonism
It binds the melanocortin-1 receptor on pigment cells, the master switch for eumelanin.
Clinical significance: Afamelanotide binds predominantly to MC1R and activates melanogenesis, increasing skin pigment independently of sun or UV exposure — a pharmacologic, not cosmetic, effect.
Molecular detail: MC1R is a Gs-coupled GPCR; activation raises cAMP, which via PKA/CREB induces MITF, the master melanogenic transcription factor. Afamelanotide binds MC1R with high affinity (EC₅₀ ≈ 0.5 nM) and is ~100× more potent than α-MSH at stimulating melanoma tyrosinase.
Grade A
🎨
2 · Eumelanin shift
It pushes melanocytes to make eumelanin — the brown/black pigment that best blocks UV.
Clinical significance: The resulting eumelanin increase reduces UV penetration and scavenges free radicals, producing a photoprotective phenotype that lengthens tolerable light exposure in EPP.
Molecular detail: MITF drives tyrosinase, TYRP1, and DCT, increasing melanosome production and shifting the pheomelanin→eumelanin balance. The pigment forms over days to weeks, not within hours — incompatible with an acute "tanning" timeline.
Grade B
🛡️
3 · Antioxidant & free-radical effects
Beyond pigment, it helps mop up the reactive molecules that light triggers in EPP skin.
Clinical significance: Afamelanotide induces antioxidant activity and reduces free-radical and cytokine formation — relevant in EPP, where light-activated protoporphyrin IX generates reactive oxygen species.
Melanocortin signaling also supports DNA-repair pathways and dampens inflammation.
Clinical significance: Afamelanotide enhances DNA-repair processes and modulates inflammation, mechanisms of interest for photodamage and explored in investigational dermatologic settings.
Molecular detail: α-MSH/MC1R signaling has been linked to nucleotide-excision-repair enhancement and reduced UV-induced apoptosis in melanocytes — part of why MC1R loss-of-function variants raise photodamage and melanoma risk.
Grade P
⏱️
5 · Why an implant, not an injection
The peptide clears fast, so a slow-release implant is what makes steady dosing possible.
Clinical significance: Afamelanotide's free-peptide half-life is only ~30 minutes, so durable photoprotection requires sustained delivery — achieved by the bioresorbable implant, not repeated injections.
Molecular detail: The implant embeds afamelanotide in a poly(DL-lactide-co-glycolide) matrix that resorbs while releasing drug over days, maintaining melanogenic stimulus across each 2-month cycle.
Grade P
🧪
6 · Stability engineering (Nle⁴, D-Phe⁷)
Two amino-acid swaps make it both stronger and far harder for the body to break down.
Clinical significance: Replacing Met⁴ with norleucine and L-Phe⁷ with D-phenylalanine yields a protease-resistant, superpotent analog — the basis for prolonged MC1R engagement vs native α-MSH.
Molecular detail: The D-Phe⁷ inversion blocks enzymatic cleavage at a vulnerable bond and locks the bioactive His-Phe-Arg-Trp core conformation; Nle⁴ removes the oxidation-prone methionine. Together they extend receptor residence time.
L3 · Cascade
Melanogenic cascade — from implant to photoprotection
💉 Implant
SC · sustained release
→
🔑 MC1R
Gs · cAMP
→
🧬 MITF
tyrosinase ↑
→
🎨 Eumelanin ↑
+ antioxidant
→
🛡️ Photoprotection
pain-free light ↑
L2 · Receptor selectivity
Melanocortin-receptor profile
Receptor
Affinity
Effect
MC1R
High (primary)
Melanogenesis · eumelanin
MC3R
Lower
Energy / inflammation (minor)
MC4R
Lower
Appetite / CNS (minor)
MC5R
Lower
Exocrine (minor)
MC2R
Negligible
(ACTH receptor — not targeted)
L2 · Structure engineering
α-MSH vs afamelanotide — two substitutions
Position
α-MSH
Afamelanotide
Effect
4
Methionine
Norleucine
Oxidation-resistant
7
L-phenylalanine
D-phenylalanine
Protease-resistant
Net
Short-acting
Superpotent, stable
~100× potency
03 · Dosing protocol & models
An implant schedule — not a dosing curve.
Afamelanotide has no self-injection dosing. The entire approved protocol is a clinician-placed implant on a fixed schedule, supported by sun-protection measures. The panels below cover the FDA EPP implant protocol, the clinical-trial schedules behind approval, the administration technique, the sustained-release pharmacology, and — explicitly — the blocked cosmetic/injection use. Every figure here is implant-schedule education; there are no cosmetic, mg/kg, cycle, or "loading" doses, and none can be generated here.
Approved-label education · implant only
Scenesse (afamelanotide) is FDA-approved (Oct 2019; EU 2014) as a single 16 mg subcutaneous implant placed every 2 months above the anterior supra-iliac crest, administered by a trained healthcare professional. Sun and light protection measures must continue during treatment. The calculator here models only this implant schedule — never cosmetic or injectable dosing.
Delivery rationale
Because the free peptide clears in ~30 minutes, durable photoprotection requires sustained release. The implant is a ~1.7 cm × 1.45 mm bioresorbable poly(DL-lactide-co-glycolide) rod containing 16 mg afamelanotide (≡18 mg acetate) that releases drug over days while resorbing.
EPP — FDA implant protocol
16 mg implant · every 2 months
Grade A
Indication
Increase pain-free light exposure in adults with a history of phototoxic reactions from EPP.
Dose
A single 16 mg afamelanotide implant subcutaneously every 2 months.
Site
Inserted above the anterior supra-iliac crest using the SFM Implantation Cannula.
Who
A healthcare professional proficient in the procedure who has completed Clinuvel training.
Adjunct care
Maintain sun/light protection (clothing, opaque sunscreens) throughout treatment.
Nature of benefit
Symptomatic — PPIX levels are unchanged; it does not protect against PPIX-mediated liver damage.
Adults only. Not for cosmetic tanning. Conduct dermatologic monitoring; afamelanotide does not replace photoprotection behaviors.
EPP · implant schedule
Label dosing summary
Parameter
Value
Source
Dose per implant
16 mg (≡18 mg acetate)
Label
Interval
Every 2 months (60 d)
Label
Route
Subcutaneous implant
Label
Administered by
Trained HCP
Label
Clinical-trial schedules
CUV039 (US) · CUV029 (EU)
Grade A
US (CUV039)
n=93 (48 afamelanotide / 45 vehicle); three 16 mg implants every 60 days; followed 180 days.
EU (CUV029)
Five implants over ~9 months, dosed every 60 days, timed across the sunlight season.
Primary endpoint
Duration of pain-free direct sunlight exposure (10:00–15:00 EU; 10:00–18:00 US) on pain-free days.
Trial schedules are presented for educational context only — they are not a prescription, and seasonal/implant counts are individualized by an EPP specialist.
Trials · schedule contrast
Pivotal phase-3 dosing
Trial
Implants
Window
CUV039 (US)
3 every 60 d
180 days
CUV029 (EU)
5 every 60 d
~9 months
Administration & handling
Aseptic implant insertion
Grade A
Technique
Insert a single implant SC above the anterior supra-iliac crest using aseptic technique and the SFM Implantation Cannula.
Operator
Only a healthcare professional proficient in the implantation procedure who has completed manufacturer training.
Device
Use only validated implantation devices; an unsuitable device could damage the implant.
Post-placement
Monitor the implant site; the bioresorbable rod is not routinely removed and resorbs over time.
Adjunct
Continue sun/light protection; afamelanotide supplements, not replaces, photoprotection.
There is no self-administration, home injection, or dose titration. Any "injectable Melanotan" is outside this approved system entirely.
Implant · specifications
Physical & handling reference
Field
Value
Source
Form
Bioresorbable rod ~1.7 cm × 1.45 mm
Label
Content
16 mg afamelanotide (≡18 mg acetate)
Label
Matrix
Poly(DL-lactide-co-glycolide)
Label
Operator
Trained HCP only
Label
Pharmacology & pharmacokinetics
Short peptide, sustained delivery
Grade B
Free-peptide t½
≈ 30 minutes — far too short for direct dosing to sustain photoprotection.
Release
The PLGA implant releases afamelanotide over days while resorbing, maintaining MC1R stimulus.
Onset of pigment
Melanin increase develops over days to weeks — not an acute effect.
Potency
~100× α-MSH at melanoma tyrosinase; MC1R EC₅₀ ≈ 0.5 nM.
Immunogenicity
Anti-afamelanotide antibody formation has been low in EPP cohorts.
The short half-life is exactly why illicit repeated self-injection is both ineffective for stable protection and uncontrolled in exposure.
PK · summary
Pharmacokinetic reference
Parameter
Value
Note
Peptide half-life
≈ 30 min
Drives implant design
Delivery
Sustained (implant)
Days of release
Pigment onset
Days–weeks
Not acute
MC1R EC₅₀
≈ 0.5 nM
High affinity
Cosmetic / injectable use — BLOCKED
Non-approved melanocortin usage
Grade D
Status
No injectable or cosmetic afamelanotide is approved; tanning use is unapproved and blocked.
Product reality
Online "Melanotan" products are unregulated and frequently bear no resemblance to afamelanotide's actual structure.
Clinuvel abandoned cosmetic development in the 2000s over regulatory and suntanning-promotion concerns.
Any workflow attempting tanning protocols, cycle design, or injectable dosing is routed to BLOCKED_OUTPUT: "Non-approved cosmetic melanocortin usage."
Hard rule
Calculator mode gate
Mode
Status
EPP implant schedule (education)
Allowed
Clinical-trial schedule (education)
Restricted
Cosmetic tanning dosing
Blocked
Injection cycles / "loading"
Blocked
Melanocortin stacking
Blocked
L2 · Approved-label implant-schedule reference
Implant-Schedule Reference Calculator
Afamelanotide is an FDA-regulated implant medication for erythropoietic protoporphyria. Injectable or cosmetic formulations are not approved and may be unsafe or illegal depending on jurisdiction. This system does not support cosmetic dosing calculation — it only models the approved 16 mg implant schedule (every 2 months) and the clinical-trial schedules, for education. It is not a prescription and does not determine eligibility.
Dose / implant
—
Interval
—
Coverage span
—
Total / season
—
Basis
—
04 · Combinations & context
EPP care context, not stacks.
In its approved setting, afamelanotide sits within an EPP management plan alongside light protection and supportive care — not within a peptide "stack." The combinations that matter are clinical adjuncts; the combinations that are blocked are the cosmetic and melanocortin pairings that drive illicit tanning use.
+ Sun/Light Protection
EPP care standard
AfamelanotideProtective measures
Photoprotection (clothing, opaque sunscreens, behavioral avoidance) is maintained throughout treatment — afamelanotide supplements, never replaces, these measures. Grade A.
Element
Role
Gate
Photoprotection
Core EPP care
Continue
+ EPP Supportive Care
Symptomatic
NSAIDsCold compresses
EPP management also includes symptomatic measures for phototoxic episodes. Afamelanotide reduces phototoxic pain frequency but is symptomatic — it does not lower PPIX or address hepatic risk. Grade A/B.
Element
Role
Gate
Symptomatic care
Phototoxic episodes
Adjunct
+ Liver Monitoring (EPP)
Disease context
PPIXHepatic monitoring
Because afamelanotide does not reduce PPIX or protect against PPIX-mediated liver damage, EPP hepatic surveillance continues independently. Grade B.
Element
Concern
Gate
Hepatic risk
PPIX-mediated
Monitor separately
+ UV / Phototherapy (EPP research)
Care-context only
AfamelanotideControlled light
In the EPP care context, increased light tolerance is the therapeutic goal under specialist supervision — distinct from cosmetic UV/tanning, which is not a sanctioned pairing. Grade C.
Element
Context
Gate
Light tolerance
EPP goal
Specialist only
+ Melanotan II
Blocked
AfamelanotideMelanotan II
Combining with Melanotan II is redundant and unsafe — MT-II is an unapproved cyclic melanocortin with broad MC3/4R activity and a poor safety profile. Blocked. Grade D.
Combination
Status
Reason
+ Melanotan II
Block
Redundant / unsafe
+ Tanning Agents / Hormones
Blocked
Tanning agentsCosmetic hormones
Pairing with tanning agents or hormones for cosmetic darkening is not approved and is blocked — these are precisely the illicit use patterns Intrasigna excludes. Grade D.
Combination
Status
Reason
+ Tanning / hormones
Block
Cosmetic, non-approved
Related Melanocortins (context)
Reference only
BremelanotideSetmelanotide
Bremelanotide (PT-141), an MT-II derivative, is FDA-approved for HSDD; setmelanotide is a selective MC4R agonist for rare obesity — distinct melanocortin drugs, not afamelanotide combinations. Grade A (context).
Agent
Target
Status
Bremelanotide
MC4R (CNS)
Approved (HSDD)
Setmelanotide
MC4R
Approved (obesity)
Self-Injection / Non-Rx Use
Blocked
Injectable "Melanotan I"
There is no approved self-injection. Injectable "Melanotan I" from online vendors is unregulated, of uncertain composition, and excluded from this system. Grade D.
Use
Status
Reason
Self-injection
Block
No approved injectable
05 · Safety & contraindications
Approved-implant safety vs illicit-injection danger.
Afamelanotide's approved-implant safety profile is well-characterized and mild — mostly implant-site reactions and pigmentation, with headache and nausea. The far larger safety story is the gulf between this regulated implant and the illicit injectable "Melanotan" market, where composition is unknown and the cyclic relative Melanotan II carries genuinely serious risks.
⛔ Cosmetic-injection warning — Injectable "Melanotan" sold online is unregulated and often chemically unlike afamelanotide. The related Melanotan II has been linked to darkening/proliferation of moles, nausea, priapism, and concern about melanoma. The only safe, approved form of afamelanotide is the clinician-placed EPP implant.
Illicit-product risksUnregulated injectables carry contamination, dosing, and composition risks.
Melanotan II-specific harmsPriapism, nausea, mole change, and melanoma concern with the cyclic analog.
Approved-implant adverse reactions (label)
Safety · label table
Reactions >2% through month 6 (CUV039/030/029)
Reaction
Pattern
Source
Implant-site reactions
~21% (vs vehicle)
Label
Skin hyperpigmentation
Common (expected)
Label
Headache
Common
Label
Nausea
Common
Label
Nasopharyngitis / back pain / fatigue
>2%
Label
Approved implant vs illicit injection — safety contrast
Safety · critical distinction
Why the form matters as much as the molecule
Dimension
Scenesse implant (approved)
Illicit injectable / MT-II
Composition
Defined 16 mg afamelanotide
Unknown / often not afamelanotide
Oversight
Trained HCP, every 2 mo
DIY, unmonitored
Receptor scope
MC1R-focused
Broad MC3/4R (MT-II)
Sexual/CNS effects
Minimal
Priapism, nausea (MT-II)
Lesion risk
No evidence of ↑ melanoma
Mole change / melanoma concern
Legality
FDA-approved (EPP)
Unapproved / often illegal
Baseline & monitoring panel
Baseline (before initiation)
Confirm biochemically/genetically established EPP (specialist porphyria testing). Document skin phototype, baseline pigmented-lesion map and lesion count, dermatology history, and screen for melanoma or premalignant/suspicious lesions and other photodermatoses.
During treatment
Monitor the implant site; track pain-free light-exposure improvement and phototoxic episodes; perform periodic full-skin dermatologic exams (afamelanotide-induced pigment can obscure lesion changes). Maintain photoprotection behaviors.
EPP-specific
Continue independent EPP hepatic surveillance (PPIX is unchanged by therapy). Reassess if new or changing pigmented lesions, suspected hypersensitivity, or implant-site complications occur.
Baseline biomarker / screening panel
Biomarkers · pre-test scaffold
Markers & screens to review
Marker / screen
Purpose
Gate
EPP confirmation (FECH / PPIX)
Establishes the only valid indication
Selection
Baseline skin phototype
Response classification
Selection
Pigmented-lesion map / count
Surveillance baseline
Safety
Melanoma / premalignant screen
Contraindication screen
Safety gate
Dermatology history
Risk stratification
Screen
UV-sensitivity / phototoxicity score
EPP severity / response
Response
Hepatic function (EPP)
PPIX liver risk unaffected by drug
Monitor separately
Contraindications & safety gates
Condition
Concern
Severity · grade
Any cosmetic tanning intent
Non-approved use; blocked
Blocked
Injectable / non-Rx "Melanotan"
Unregulated, uncertain composition
Blocked
Melanoma history / suspicious lesions
Requires evaluation; complicates surveillance
Do not initiate
Undiagnosed pigment disorder
No valid indication without diagnosis
Avoid
Concurrent Melanotan II
Redundant + unsafe
Block
Pregnancy (non-indicated use)
Insufficient data (AU category B1)
Provider review
Pediatric use (outside label)
Adults-only approval
Not established
Other photodermatoses
Outside EPP indication
Not established
Significant hepatic dysfunction
EPP trial exclusion
Specialist review
Premalignant skin lesions
Surveillance complexity
Evaluate first
Implant-site reaction history
Local reactions common
Monitor
New / changing nevi during therapy
Lesion-change surveillance
Dermatology exam
Reliance on drug vs photoprotection
Symptomatic only
Continue protection
Self-administration intent
Implant is HCP-placed
Not permitted
"Loading" / cycle protocols
No such approved concept
Blocked
Melanocortin stacking
Non-approved
Blocked
Unsupervised home use
Requires trained HCP
Avoid
Reliance on online "Melanotan" supply
Unknown composition/contamination
Blocked
Bremelanotide / setmelanotide confusion
Different receptor & indication
Distinguish
Concurrent serious hypersensitivity
Prior reaction to product
Evaluate
GRADE summary — Afamelanotide is Grade A for its sole validated indication: increasing pain-free light exposure in adults with EPP, delivered as a clinician-placed 16 mg implant every 2 months. Its approved-implant safety profile is favorable (implant-site reactions, hyperpigmentation, headache, nausea), and there is no evidence it increases melanoma risk — eumelanin is photoprotective. Risk is concentrated entirely in off-label cosmetic and illicit injectable use, which is unvalidated, uncontrolled in composition, and explicitly blocked. The decisive levers are confirmed EPP diagnosis, trained-clinician implantation, pigmented-lesion surveillance, and continued photoprotection — never cosmetic dosing, self-injection, or melanocortin stacking.
06 · Trials & evidence base
A rare-disease approval, built on RCTs.
Afamelanotide's approval rests on randomized, vehicle-controlled phase-3 trials in EPP showing more pain-free time in sunlight — the first therapy ever approved to increase light exposure in this disease. Beyond EPP, its melanogenic, antioxidant, and DNA-repair biology has been explored in other dermatologic settings, all still investigational.
CUV039 · US P3
pain-free light ↑
n=93 (48 afa/45 vehicle), 3 implants, 180 d. NCT01605136.
CUV029 · EU P3
pain-free light ↑
5 implants over ~9 months across the sunlight season. Langendonk 2015.
FDA Oct 2019 (orphan/priority); EU 2014. First EPP therapy.
AHuman · pivotal RCTs
Afamelanotide for erythropoietic protoporphyria (Langendonk 2015)
Two phase-3 multicenter, randomized, double-blind, vehicle-controlled trials (EU CUV029, US CUV039) assessed 16 mg implants every 60 days. Both measured duration of pain-free direct sunlight exposure and supported FDA/EMA approval — the evidence backbone of afamelanotide's only validated indication.
The label defines the 16 mg implant, the every-2-months schedule, supra-iliac insertion via the SFM cannula, the EPP indication, the safety database (n=244), the adverse-reaction profile, and the requirement for a trained clinician — the regulatory backbone of this page.
EPP arises from ferrochelatase (FECH) gene mutations (≈98% carry the IVS3-48T>C variant), causing protoporphyrin IX accumulation and severe light-triggered pain. Afamelanotide raises eumelanin to lengthen tolerable light exposure, but PPIX and hepatic risk are unchanged.
Afamelanotide activates MC1R → Gs → cAMP → MITF → tyrosinase to drive eumelanin synthesis, with ~100× the potency of α-MSH and MC1R EC₅₀ ≈ 0.5 nM — the molecular basis for its durable, sun-independent pigmentation.
Vitiligo, ischemic stroke & other exploratory uses
Afamelanotide has been explored experimentally in vitiligo, acute ischemic stroke, and antimicrobial contexts — all investigational and unproven. These remain outside approved use and are not endorsed indications.
Regulators warn that online "Melanotan" tanning products are unregulated and chemically often unlike afamelanotide; the cyclic Melanotan II is linked to mole change, nausea, priapism, and melanoma concern — the core reason cosmetic use is blocked here.
An ELISA evaluation of afamelanotide immunogenicity in EPP patients detected low rates of anti-afamelanotide (and anti-α-MSH) antibodies, consistent with the favorable long-term tolerability observed with repeated implants.
Each Scenesse implant is a ~1.7 cm × 1.45 mm bioresorbable PLGA rod containing 16 mg afamelanotide (≡18 mg acetate), inserted SC above the anterior supra-iliac crest every 2 months with the SFM cannula by a trained healthcare professional — a fixed schedule, not a titratable dose.
Met⁴→norleucine and L-Phe⁷→D-phenylalanine convert α-MSH into a protease-resistant, conformationally locked analog; the sequence Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂ retains the His-Phe-Arg-Trp core that drives MC1R activation.
Through month 6 across CUV029/030/039, reactions >2% included implant-site reactions (~21%), skin hyperpigmentation, headache, nausea, nasopharyngitis, back pain, and fatigue — a mild, predominantly local and pigment-related profile consistent with the mechanism.
There is no evidence afamelanotide increases melanoma risk — eumelanin reduces UVB penetration and scavenges free radicals, protecting the skin. The practical caveat is that induced pigmentation can complicate pigmented-lesion surveillance, warranting periodic dermatologic exams.
Receptor subtype defines the drug: afamelanotide targets MC1R for pigmentation, bremelanotide (PT-141) targets MC4R for HSDD, and setmelanotide is a selective MC4R agonist for rare genetic obesity — none interchangeable with afamelanotide.
Clinuvel abandoned cosmetic tanning development in the 2000s over regulatory and suntanning-promotion concerns, redirecting afamelanotide toward rare-disease use; it reached EU approval in 2014 and FDA approval (orphan/priority) in October 2019 as the first EPP therapy.
Afamelanotide is Australian pregnancy category B1, with insufficient data for non-indicated use; the approval is restricted to adults with EPP — pediatric and other-photodermatosis use is not established, reinforcing the narrow, validated scope.
The single most important comparison on this page is also the most misunderstood: Melanotan I (afamelanotide) and Melanotan II are different molecules with different shapes, receptor profiles, approval status, and safety. Afamelanotide is a linear, MC1R-focused, FDA-approved implant; Melanotan II is a cyclic, broad-acting, unapproved injectable. Other melanocortin drugs target different receptors entirely.
Feature
Melanotan I (afamelanotide)
Melanotan II
Structure
Linear 13-aa α-MSH analog
Shorter cyclic peptide
Receptors
MC1R (primary)
MC1R + broad MC3/4/5R (CNS)
Approval
Yes — Scenesse implant (EPP)
None
Delivery
Clinician implant
DIY injection (illicit)
Tanning effect
Secondary (pharmacologic)
Stronger but unregulated
Sexual / CNS effects
Minimal
Marked (libido, priapism)
Safety profile
Clinically studied, favorable
Poorly characterized; case reports of harm
Melanoma concern
No evidence of ↑ risk
Mole change; melanoma concern
Intrasigna status
Approved-label (EPP only)
Blocked
L2 · melanocortin drugs
Where afamelanotide sits among melanocortin agonists
L1 · Consumer — Melanotan I (afamelanotide, brand Scenesse) is a prescription implant that boosts the skin's own protective pigment (eumelanin). It is approved only to help adults with a rare disease called EPP spend more pain-free time in sunlight, and it is placed under the skin by a doctor every two months. It is not a tanning drug. Injectable "Melanotan" sold online is unregulated and is not the same thing — and the related Melanotan II is a different, riskier compound. Cosmetic use is not supported here.
L2 · Clinical — Afamelanotide is an α-MSH analog and MC1R agonist approved as a 16 mg bioresorbable subcutaneous implant, placed above the anterior supra-iliac crest every 2 months by a trained clinician, to increase pain-free light exposure in adults with EPP. Benefit is symptomatic (PPIX unchanged; hepatic risk unaffected). It is well tolerated — mainly implant-site reactions, hyperpigmentation, headache, and nausea. Confirmed EPP diagnosis, pigmented-lesion surveillance, and continued photoprotection are the key management points; cosmetic, injectable, and stacking uses are blocked.
L3 · Research — Afamelanotide ([Nle⁴,D-Phe⁷]-α-MSH; C₇₈H₁₁₁N₂₁O₁₉, 1646.87 Da) is a protease-resistant, superpotent α-MSH analog (~100× potency; MC1R EC₅₀ ≈ 0.5 nM) acting via MC1R-Gs-cAMP-MITF to drive eumelanin synthesis, with antioxidant, DNA-repair, and anti-inflammatory actions. Its ~30-minute free-peptide half-life mandates sustained-release implant delivery. Pivotal vehicle-controlled phase-3 trials (CUV029/CUV039, Langendonk 2015) established increased pain-free light exposure in EPP; exploratory work spans vitiligo and ischemic stroke. The illicit "Melanotan" market and the cyclic, broad-receptor Melanotan II are pharmacologically and clinically distinct, and carry the safety concerns that define the blocked cosmetic use case.
08 · References & evidence
Source register.
Evidence grades reflect the strength of support for the specific claim cited, not the prestige of the journal. Afamelanotide's FDA label and the pivotal EPP RCTs are its firmest evidence; mechanistic, illicit-market, and database sources anchor pharmacology, safety, identity, and the critical Melanotan I-vs-II distinction.