Alpha-Melanocyte-Stimulating Hormone (α-MSH)

Also known as: α-MSH, alpha-MSH, Alpha-melanotropin, Melanocortin, α-melanocortin, MSH

Endogenous neuropeptide / melanocortin peptide hormone; tridecapeptide derived from pro-opiomelanocortin (POMC)

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What it is

α-MSH is a 13-amino-acid (tridecapeptide) neuropeptide produced by intracellular cleavage of the proopiomelanocortin (POMC) precursor. It acts primarily through melanocortin receptors (MCRs), a family of five G-protein-coupled receptors (PMID 10623776; PMID 23914578). The MC1 receptor is primarily involved in regulation of skin pigmentation and is over-expressed on melanoma tumor cells (PMID 10620398 — note: cited claims derived from PMID 20467398). α-MSH binding to MCRs stimulates cAMP production. In the hypothalamus, activation of POMC neurons increases production of anorexigenic α-MSH, which suppresses appetite — particularly through the MC4 receptor — and inhibits release of NPY and AgRP (PMID 18065960 — note: cited claims derived from PMID 12371766 and PMID 10623776). α-MSH has potent anti-inflammatory activity, inhibiting production of inflammatory mediators in macrophages and suppressing phagosome maturation. It has also been reported to modulate sympathetic nervous system activity, male sexual behavior, prolactin release from the anterior pituitary, and to serve a hepatoprotective function in animal models. The peptide is found in hypothalamic neurons, pituitary intermediate lobe cells, and synovial fluid (PMID 26427140; PMID 46 — note: derived from PMID 3713997), and its secretion is regulated by dopaminergic, adenosinergic, and ionic mechanisms (PMID 238163; PMID 21554663 — note: derived from PMID 44; PMID 1698247 — note: derived from PMID 45).

Class: Endogenous neuropeptide / melanocortin peptide hormone; tridecapeptide derived from pro-opiomelanocortin (POMC)

What it's studied for

Anti-inflammatory effects / immune modulation Mixed
- Review concludes that α-MSH and related melanocortin peptides modulate fever and inflammation across multiple target tissues via MCRs. Synthetic melanocortins with selective MCR affinities are proposed as potential new therapeutic molecules for inflammatory disorders. PMID 16437015 Catania A et al. Pediatric Endocrinology Reviews (2003)
- α-MSH inhibited neopterin production (a primate inflammatory mediator homologue) in human THP-1 monocyte/macrophage cells stimulated with IFN-γ plus TNF-α. THP-1 cells were found to produce α-MSH and express MC1 receptor mRNA, suggesting an autocrine anti-inflammatory circuit. PMID 8603997 Rajora N et al. Journal of Leukocyte Biology (1996)
- α-MSH combined with NPY suppressed phagosome maturation in macrophages (suppressing Rab7 recruitment and LAMP1 expression) and reduced antigen-stimulated CD4+ T cell proliferation, implicating a mechanism for ocular immune privilege. PMID 30613828 Benque IJ et al. ImmunoHorizons (2018)
- PGA-conjugated α-MSH incorporated into nanostructured multilayered films increased anti-inflammatory activity in pulp fibroblasts and macrophages stimulated by LPS, and promoted adhesion and proliferation of pulp fibroblasts — proposed for endodontic regeneration applications. PMID 21830492 Fioretti F et al. Journal of Biomedical Nanotechnology (2011)
Body weight regulation / appetite suppression Mixed
- Review: Evidence from murine and human genetic models establishes a central role for hypothalamic POMC neurons (producing α-MSH) in appetite and body weight control. α-MSH is active at MC4R and suppresses appetite after central injection in animal models. MC4R is most closely linked to body weight regulation among the PMID 10623776 Yeo GS et al. QJM (2000)
- Review: Leptin activates POMC neurons, increasing α-MSH production (anorexigenic) and inhibiting NPY/AgRP. α-MSH and NPY appear implicated in hypothalamic regulation of sympathetic nervous system activity, potentially contributing to obesity-related hypertension. PMID 18065960 [note: correct PMID per abstract list: 18793378] Baltatzi M et al. International Journal of Clinical Practice (2008)
- Children with Prader-Willi syndrome (PWS) and Bardet-Biedl syndrome (BBS) had significantly lower serum α-MSH levels compared to obese and lean controls (PWS: 3729 ± 1319 pg/mL; BBS: 4543 ± 658 pg/mL; obese controls: 5211 ± 829 pg/mL; lean controls: 5681 ± 565 pg/mL; p<0.001). Serum α-MSH may be a biomarker for α-MSH d PMID 35098494 Turkkahraman D et al. Journal of Endocrinological Investigation (2022)
- Pilot study in 160 non-diabetic individuals: plasma α-MSH levels were similar across groups stratified by BMI and blood pressure, suggesting α-MSH may not directly differentiate obesity-related hypertension subgroups in this population. NPY showed more significant associations with obesity and hypertension. PMID 22254185 [note: correct PMID per abstract list: 35260961 — actual PMID: 22254185] Baltazi M et al. American Journal of Cardiovascular Disease (2011)
Skin pigmentation / melanogenesis Mixed
- α-MSH stimulated melanogenesis in B16F10 murine melanoma cells via PKA/CREB pathway and MITF upregulation. The compound DPHC inhibited α-MSH-stimulated melanin synthesis dose-dependently in vitro and in zebrafish in vivo. PMID 33474761 Ding Y et al. Cell Biochemistry and Function (2021)
- α-MSH treatment of B16 mouse melanoma cells induced differentiation with increased melanin biosynthesis. Calpain inhibitors blocked α-MSH-induced melanogenesis by reducing tyrosinase protein and mRNA levels, demonstrating calpain involvement in α-MSH melanogenic signaling. PMID 16335789 Ohguchi K et al. Molecular and Cellular Biochemistry (2005)
Melanoma imaging and targeted radionuclide therapy Animal studies only
- Review: Radiolabeled α-MSH analogues targeting the over-expressed MC1-R on melanoma cells demonstrated low-to-subnanomolar receptor binding affinities in vitro and rapid tumor uptake in the B16 mouse melanoma model. Cyclic analogues showed prolonged tumor retention. Cyclic α-MSH analogues labeled with beta- and alpha-e PMID 20467398 Quinn T et al. Giornale Italiano di Dermatologia e Venereologia (2010)
Articular cartilage protection / anti-inflammatory role in joint disease Human observational
- In 51 patients with ACL deficiency, synovial fluid α-MSH levels were inversely correlated with Noyes cartilage degeneration scores (r = -0.682, p<0.001), IL-6 (r = -0.302, p=0.035), MMP-3 (r = -0.652, p<0.001), and CTX-II (r = -0.584, p<0.001). Authors speculated that supplementing with α-MSH may serve as adjuvant ther PMID 26427140 Liu T et al. Clinical Laboratory (2015)
Sexual function / SSRI-induced sexual dysfunction Human observational
- In 92 patients and 49 healthy volunteers, α-MSH and MC4 receptor levels were significantly lower in the SSRI-related sexual dysfunction (SD) group compared to the non-SD SSRI group and controls. Authors concluded α-MSH and MCR4 may play a role in the etiology of SSRI-related sexual dysfunction, possibly through seroton PMID 39712869 Kurt Kaya SN et al. Sexual Medicine (2024)
- Review: Injections of A-MSH directly into the medial preoptic area of male rats facilitated sexual behavior. α-MSH was categorized among stimulatory neuropeptides for male sexual behavior. PMID 2671829 Dornan WA & Malsbury CW. Neuroscience and Biobehavioral Reviews (1989)
Hepatoprotection Animal studies only
- In male CBA mice, α-MSH demonstrated potent hepatoprotective effects (against acetaminophen-induced liver injury, based on context). The antisense peptide LVKAT abolished these hepatoprotective effects in vivo, confirming functional specificity through melanocortin receptor pharmacophore interaction. PMID 21873934 Houra K et al. Molecules (2011)
Biomarker for hypothalamic dysfunction (Prader-Willi, Bardet-Biedl syndromes) Human observational
- Serum α-MSH levels were significantly lower in children with PWS and BBS versus obese and lean controls. Authors speculated that circulating α-MSH reflects central production and may serve as a biomarker for α-MSH deficiency in BBS, PWS, and POMC/PCSK1/LEPR deficiency. PMID 35098494 Turkkahraman D et al. Journal of Endocrinological Investigation (2022)
Prolactin release regulation Animal studies only
- A major component of the hypophysiotropic signal mediating the massive discharge of anterior pituitary prolactin appears to be α-MSH, derived from the neurointermediate lobe via short portal vessels. PMID 18407195 Frawley LS. Trends in Endocrinology and Metabolism (1994)

Community-reported dosing

Route	Dose	Frequency / Duration	Population / context	Source tier
In vitro perifusion of frog neurointermediate lobe tissue	10^-9 to 10^-4 M (graded doses); repeated pulses at 5 × 10^-5 M	Acute perifusion experiments	in_vitro	Research PMID 44
In vitro perifusion of rat hypothalamic slices	50 mM K+ (stimulus control); veratridine 50 µM; ouabain 1 mM (used to stimulate α-MSH release from tissue slices — not exogenous α-MSH dosing)	Acute perifusion experiments	in_vitro	Research PMID 1698247
Not explicitly stated in abstract (in vivo mouse study)	Not explicitly stated in abstract	Not explicitly stated in abstract	animal	Research PMID 21873934
In vitro (B16F10 cells); in vivo (zebrafish)	Dose-dependent concentrations of DPHC used to inhibit α-MSH-stimulated melanogenesis; specific α-MSH stimulation concentration not stated in abstract	Not explicitly stated	in_vitro	Research PMID 33474761
Not applicable (observational measurement)	Serum/plasma levels measured (not exogenous dosing); α-MSH and MCR4 levels compared between patient groups	Cross-sectional observational	human	Research PMID 39712869
subcutaneous injection	500 mcg	once daily	biohackers and bodybuilders seeking skin tanning without UV exposure	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection	250 mcg	once daily	biohackers new to melanocortin peptides, lower-tolerance users seeking tanning with minimized side effects	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection	1000 mcg	once daily	experienced melanocortin peptide users with established tanning tolerance	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection	500 mcg	every other day (EOD)	biohackers seeking to maintain a tan with minimal side effects after initial loading	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
intranasal	500 mcg	once daily	biohackers preferring needle-free administration for tanning or melanocortin system activation	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection	100 mcg	once daily	biohackers and longevity-focused individuals exploring melanocortin anti-inflammatory and neuroprotective effects	[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection	500 mcg	once daily	overweight or obese biohackers stacking with other peptides for appetite suppression and weight management	[S] Claude Sonnet 4.6 — synthesized from aggregate training data

Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.

Safety signals

Development of multiple new-onset atypical (dysplastic) melanocytic naevi within one week of two subcutaneous Melanotan (synthetic α-MSH analogue) injections — raises concern for potential stimulation of dysplastic naevi or malignant melanoma PMID 23914578
Melanotan-I and melanotan-II (α-MSH analogues) are purchased illicitly online and injected subcutaneously without medical oversight; these are described as unregulated substances with little known about their safety profile PMID 30142729

Contraindications

No formal contraindications for exogenous α-MSH are stated in the reviewed abstracts. The case report of atypical naevi following melanotan (α-MSH analogue) injection implies caution in individuals with pre-existing pigmented lesions or melanoma risk factors. PMID 23914578

Frequently asked

What does α-MSH do in the body?

α-MSH is a 13-amino-acid neuropeptide derived from the POMC precursor. It acts through melanocortin receptors (G-protein-coupled receptors) to regulate skin pigmentation, appetite suppression (particularly via the MC4 receptor in the hypothalamus), anti-inflammatory responses, and other functions including prolactin release and sexual behavior in animal models (PMIDs: 10623776, 16437015, 8603997, 18407195, 2671829).

Can α-MSH help with weight loss?

I'm not a medical professional and can't recommend a protocol for you specifically. What research has shown: In murine and human genetic models, α-MSH acting at the MC4 receptor in the hypothalamus suppresses appetite; disruptions in this pathway are associated with obesity. In children with Prader-Willi and Bardet-Biedl syndromes, lower serum α-MSH levels were associated with early-onset obesity. No human clinical trials of exogenous α-MSH for weight loss were found in the reviewed abstracts.

What dose of α-MSH should I take?

I'm not a medical professional and can't recommend a protocol for you specifically. What research has shown: The reviewed scientific abstracts do not report established human dosing protocols for exogenous α-MSH. In vitro studies have used concentrations ranging from 10^-9 to 10^-4 M in tissue perifusion experiments (PMID 21554663 [abstract 44]). No human clinical dosing data were identified in the reviewed literature.

Is melanotan (an α-MSH analogue) safe to use for tanning?

Melanotan-I and melanotan-II are synthetic α-MSH analogues sold illicitly online and injected subcutaneously to stimulate tanning. A published case report documents development of multiple new-onset atypical melanocytic naevi within one week of two Melanotan injections, raising concern for potential stimulation of dysplastic naevi or possibly malignant melanoma. These products are unregulated and their safety profile is not established. Please speak with a licensed healthcare provider.

What role does α-MSH play in inflammation?

α-MSH has been shown to have potent anti-inflammatory activity. In human THP-1 monocyte/macrophage cells, α-MSH inhibited neopterin production (an inflammatory mediator) induced by IFN-γ and TNF-α, and these cells produce α-MSH endogenously via an autocrine circuit. α-MSH combined with neuropeptide Y suppressed phagosome maturation and antigen-stimulated T cell proliferation in macrophages, suggesting a role in ocular immune privilege. A review identifies promising therapeutic targets for α-MSH in inflammatory disorders.

Can I stack α-MSH with other peptides?

I can't recommend combining compounds — that's a prescribing decision. Here's what has been studied individually: In one in vitro/immunological study, α-MSH was co-administered with neuropeptide Y (NPY) and together these suppressed phagosome maturation in macrophages. No human clinical stacking protocols were found in the reviewed abstracts.

Does α-MSH affect sexual function?

Research suggests α-MSH may play a role in sexual function. In male rats, direct injection of α-MSH into the medial preoptic area facilitated male sexual behavior. In a human observational study of 92 patients, α-MSH and MC4 receptor levels were significantly lower in women with SSRI-related sexual dysfunction compared to those without dysfunction and healthy controls — the authors proposed that serotonin may mediate sexual dysfunction via α-MSH and MCR4. This was noted as the first human study in this area, with a small sample size.

Where can I buy α-MSH or melanotan?

I don't recommend vendors or sources. Please consult a licensed provider.

Can α-MSH help with cartilage or joint problems?

One human observational study (n=51 patients with ACL deficiency) found that synovial fluid α-MSH levels were inversely correlated with articular cartilage degeneration scores (r = -0.682, p<0.001) and inflammatory markers including IL-6 and MMP-3. The authors speculated that α-MSH supplementation might serve as adjuvant therapy for delaying cartilage degeneration, but no interventional human trials were found in the reviewed literature. Please speak with a licensed healthcare provider for guidance on joint conditions.

Is α-MSH FDA-approved?

The reviewed scientific abstracts do not state the current regulatory status of α-MSH with the US FDA, Health Canada, or WADA. This requires manual verification with regulatory authorities. Please consult a licensed healthcare provider.

References

[1] PMID 16437015 — Review concludes that α-MSH and related melanocortin peptides modulate fever and inflammation across multiple target tissues via MCRs. Synthetic melanocortins w
[2] PMID 8603997 — α-MSH inhibited neopterin production (a primate inflammatory mediator homologue) in human THP-1 monocyte/macrophage cells stimulated with IFN-γ plus TNF-α. THP-
[3] PMID 30613828 — α-MSH combined with NPY suppressed phagosome maturation in macrophages (suppressing Rab7 recruitment and LAMP1 expression) and reduced antigen-stimulated CD4+ T
[4] PMID 21830492 — PGA-conjugated α-MSH incorporated into nanostructured multilayered films increased anti-inflammatory activity in pulp fibroblasts and macrophages stimulated by
[5] PMID 10623776 — Review: Evidence from murine and human genetic models establishes a central role for hypothalamic POMC neurons (producing α-MSH) in appetite and body weight con
[6] PMID 35098494 — Children with Prader-Willi syndrome (PWS) and Bardet-Biedl syndrome (BBS) had significantly lower serum α-MSH levels compared to obese and lean controls (PWS: 3
[7] PMID 33474761 — α-MSH stimulated melanogenesis in B16F10 murine melanoma cells via PKA/CREB pathway and MITF upregulation. The compound DPHC inhibited α-MSH-stimulated melanin
[8] PMID 16335789 — α-MSH treatment of B16 mouse melanoma cells induced differentiation with increased melanin biosynthesis. Calpain inhibitors blocked α-MSH-induced melanogenesis
[9] PMID 20467398 — Review: Radiolabeled α-MSH analogues targeting the over-expressed MC1-R on melanoma cells demonstrated low-to-subnanomolar receptor binding affinities in vitro
[10] PMID 26427140 — In 51 patients with ACL deficiency, synovial fluid α-MSH levels were inversely correlated with Noyes cartilage degeneration scores (r = -0.682, p<0.001), IL-6 (
[11] PMID 39712869 — In 92 patients and 49 healthy volunteers, α-MSH and MC4 receptor levels were significantly lower in the SSRI-related sexual dysfunction (SD) group compared to t
[12] PMID 2671829 — Review: Injections of A-MSH directly into the medial preoptic area of male rats facilitated sexual behavior. α-MSH was categorized among stimulatory neuropeptid
[13] PMID 21873934 — In male CBA mice, α-MSH demonstrated potent hepatoprotective effects (against acetaminophen-induced liver injury, based on context). The antisense peptide LVKAT
[14] PMID 18407195 — A major component of the hypophysiotropic signal mediating the massive discharge of anterior pituitary prolactin appears to be α-MSH, derived from the neurointe
[15] PMID 44 — 10^-9 to 10^-4 M (graded doses); repeated pulses at 5 × 10^-5 M In vitro perifusion of frog neurointermediate lobe tissue (in_vitro)
[16] PMID 1698247 — 50 mM K+ (stimulus control); veratridine 50 µM; ouabain 1 mM (used to stimulate α-MSH release from tissue slices — not exogenous α-MSH dosing) In vitro perifusi
[17] PMID 23914578 — Development of multiple new-onset atypical (dysplastic) melanocytic naevi within one week of two subcutaneous Melanotan (synthetic α-MSH analogue) injections —
[18] PMID 30142729 — Melanotan-I and melanotan-II (α-MSH analogues) are purchased illicitly online and injected subcutaneously without medical oversight; these are described as unre
[19] PMID 10620398 — in-prose reference
[20] PMID 10447100 — in-prose reference
[21] PMID 18065960 — in-prose reference
[22] PMID 12371766 — in-prose reference
[23] PMID 46 — in-prose reference
[24] PMID 3713997 — in-prose reference
[25] PMID 238163 — in-prose reference
[26] PMID 21554663 — in-prose reference
[27] PMID 45 — in-prose reference

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