Limited · human
This Austrian real-world study examined afamelanotide treatment outcomes in 20 patients with erythropoietic protoporphyria (EPP), a rare genetic disorder causing severe phototoxic reactions upon light exposure. Researchers compared pre- and post-treatment data on quality of life (QoL), phototoxic burn tolerance time (PBTT), UV index, and the incidence and severity of phototoxic reactions for the year 2023. The study found that the EPP-specific QoL score increased markedly, with the median rising from 11.11 to 79.17 under therapy. PBTT also improved substantially, increasing from a median of 15 minutes before treatment to 250 minutes during treatment. The proportion of patients experiencing phototoxic reactions fell from 88% at baseline to 33% on therapy. Reported side effects were described as only mild and transient. The authors concluded that these findings support the effectiveness and safety of afamelanotide in EPP. Limitations include the small sample size (n=20), the non-randomized, uncontrolled observational design, and the potential for recall or reporting bias inherent to real-world cohort studies.
Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG · Mar 2026DOI ↗ Review
This narrative review examines the current and investigational pharmacological treatments for erythropoietic protoporphyrias (EPP), a group of ultra-rare inherited disorders of heme biosynthesis causing severe, painful phototoxic reactions triggered by visible light exposure. The authors searched PubMed and clinical trial databases to synthesize available evidence on two investigational agents—dersimelagon (a melanocortin-1 receptor agonist) and bitopertin (a glycine transport inhibitor)—alongside the only currently approved therapy, afamelanotide. The review notes that afamelanotide effectively reduces pain and extends tolerable sun exposure time but does not address the underlying disease mechanism and is approved only for adults, leaving pediatric patients without a treatment option. The authors report that available trial data for both dersimelagon and bitopertin suggest treatment effects versus placebo, though they emphasize that the safety and efficacy profiles of both agents require further characterization. A key limitation highlighted is the absence of head-to-head comparison data against afamelanotide, which the authors argue is necessary to inform regulatory decisions and ensure meaningful patient access. The review concludes that both agents hold promise but that additional robust clinical evidence is needed before their roles in EPP management can be fully established.
Expert opinion on pharmacotherapy · Mar 2026DOI ↗ Review
This systematic review, conducted following PRISMA guidelines, synthesizes findings from 68 peer-reviewed studies examining the mechanisms, clinical applications, formulations, and adverse effects of four major sunless tanning agents: dihydroxyacetone (DHA), melanotan (I and II), forskolin, and carotenoids. The authors found that DHA produces skin pigmentation through the Maillard reaction (a non-enzymatic browning of amino acids in the stratum corneum) and has shown additional dermatologic utility in vitiligo and erythropoietic protoporphyria, as well as potential antifungal properties—though concerns about cytotoxicity, genotoxicity, and systemic absorption were noted. Melanotan I and II, which act on melanocortin receptors, were associated with serious adverse effects in unregulated use, including rhabdomyolysis, renal infarction, and priapism. Forskolin was reported to stimulate melanin production independently of melanocortin receptors, with efficacy demonstrated primarily in animal models. Orally ingested carotenoids were found to accumulate in skin and subcutaneous fat, producing a yellow-orange hue. The review acknowledges significant limitations: lack of standardized reporting, heterogeneous outcomes across studies, and insufficient long-term human safety data, particularly for forskolin and carotenoids. The authors conclude that further rigorous clinical research and updated regulatory guidance are needed.
The Journal of clinical and aesthetic dermatology · Feb 2026Source ↗ In vitro
This study investigated the chemical and physical stability of afamelanotide (melanotan-1), a synthetic 13-amino acid peptidomimetic of α-melanocyte stimulating hormone (α-MSH) approved as an orphan drug for erythropoietic protoporphyria. Researchers subjected the compound to a range of stress conditions — acidic, basic, neutral, oxidative, UV light exposure, and elevated temperature (60°C) — following International Council for Harmonisation (ICH) guidelines Q1A(R2) and Q5C. Using gradient reversed-phase HPLC coupled with ultra-high-performance liquid chromatography–high resolution tandem mass spectrometry (UHPLC-HRMS/MS), the team identified and structurally characterized 14 distinct degradation products. Collision-induced dissociation fragmentation patterns enabled detailed elucidation of each product's structure. Key degradation pathways identified included truncation, methylation, deacetylation, and oxidation. The analytical method was validated per ICH Q2(R1) guidelines. This work is purely analytical and pharmaceutical in nature — it does not involve human subjects, animals, or cell-based experiments. Its primary value lies in establishing a comprehensive stability profile of afamelanotide to inform rational drug formulation design. No clinical outcomes, efficacy, or safety data in biological systems were assessed.
Journal of pharmaceutical and biomedical analysis · Jan 2026DOI ↗ Limited · human
This prospective qualitative study surveyed 104 consecutive patients attending a pigmented lesion clinic at a tertiary referral dermatology centre in Ireland to examine the characteristics, attitudes, and behaviours of sunbed users. Using an anonymous self-reported questionnaire, researchers collected data on demographics, frequency of sunbed use, motivations, and use of unregulated tan-enhancing agents such as Melanotan I and II. The study found that sunbed users were predominantly younger women living in urban areas, consistent with prior literature. Regulatory non-compliance was widespread: over half of sunbed premises reportedly did not provide protective goggles, and nearly half offered no health risk information to customers. Key motivations for use included improving appearance and self-confidence. Notably, greater awareness of health risks did not correlate with reduced sunbed use, suggesting a potentially compulsive or addictive behavioural pattern. Users of tan-enhancing agents also used sunbeds more frequently than non-users. The authors suggest psychological interventions such as cognitive behavioural therapy may be beneficial and call for stricter regulatory enforcement. Limitations include the single-centre design, small sample size, self-reported data susceptible to bias, and a clinic-based population that may not represent the general public.
Skin health and disease · May 2025DOI ↗ Limited · human
This German post-authorisation safety study (PASS; EUPAS13004) evaluated the real-world safety and clinical effectiveness of afamelanotide 16 mg (SCENESSE) in 200 patients with erythropoietic protoporphyria (EPP), a rare inherited disorder causing severe acute phototoxicity upon light exposure. As an ongoing observational study linked to the European EPP Disease Registry, it collected treatment-emergent adverse events as the primary safety variable and used the validated EPP-Quality of Life (EPP-QoL) tool alongside treatment continuity as effectiveness measures. The study found that afamelanotide's real-world safety and benefit-risk profile was consistent with that observed in prior clinical trials. Patients reported a statistically significant improvement in quality of life compared to baseline (p-value not fully quoted in the abstract). High treatment continuity was also noted, suggesting ongoing clinical benefit. Key limitations include the absence of an untreated comparator group within this cohort, the observational (non-randomised) design, and potential for selection bias inherent in registry-based studies. The authors concluded that afamelanotide demonstrated a positive safety profile and was associated with improved quality of life in EPP patients under real-world conditions.
Photodermatology, photoimmunology & photomedicine · Mar 2025DOI ↗ Review
This review paper examines the history, development, and scientific utility of key synthetic tool compounds used to study the melanocortin receptor (MCR) family — a group of five Class A G protein-coupled receptors (GPCRs) involved in diverse physiological processes including pigmentation, steroidogenesis, and energy homeostasis. The authors trace how synthetic derivatives of the endogenous agonist α-MSH, including NDP-MSH (melanotan I), melanotan II (MTII), and SHU9119, have become essential pharmacological tools for the field. The review discusses how these compounds are used to validate cell lines stably expressing melanocortin receptors, serve as reference ligands in high-throughput screening, inform structure-activity relationship (SAR) studies, and act as core ligands in cryo-EM structural investigations of active and inactive receptor complexes. The paper also notes that these tool compounds have served as scaffolds for FDA-approved drugs. Limitations of the review include its descriptive, non-experimental nature and its focus on synthesizing existing literature rather than presenting new empirical data. It provides important context for researchers working on MCR pharmacology but does not itself generate clinical or mechanistic evidence.
ACS pharmacology & translational science · Aug 2024DOI ↗ Animal only
This animal study investigated how the central nervous system melanocortin (CNS-MC) system influences feed intake, metabolic hormones, and insulin sensitivity in sheep. Ewes were surgically fitted with intracerebroventricular (ICV) cannulas and infused with artificial cerebrospinal fluid (aCSF), the α-MSH analog melanotan-I (MTI), or agouti-related peptide (AGRP) directly into the third ventricle. The study found that ICV MTI infusion significantly reduced voluntary feed intake, while AGRP infusion modestly increased it. MTI also elevated plasma triiodothyronine and thyroxine independently of changes in food intake, suggesting a direct central effect on thyroid hormone regulation. Notably, MTI did not affect plasma glucose, insulin, or cortisol under normal feeding conditions. However, during hyperinsulinemic-euglycemic clamp experiments in energy-restricted ewes, MTI impaired insulin's ability to suppress endogenous glucose production, indicating reduced hepatic insulin sensitivity. MTI also tended to lower plasma leptin in a feeding-level-dependent manner, with no effect on adiponectin. AGRP infusion did not significantly alter any measured plasma metabolic variables. The authors concluded that the CNS-MC system plays a role in regulating metabolic efficiency and peripheral insulin action in ruminants. Limitations include small sample sizes, a single non-human species, and the invasive ICV delivery route.
Journal of animal science · Jan 2023DOI ↗