Melanotan II
Also known as: MT-2 · MT-II · Melanotan 2
Contents
MW
1024.18 Da
Amino Acids
7 AA
Half-Life
1 hour
Route
SubQ
CAS
121062-08-6
Formula
C50H69N15O9
Amino Acid Sequence
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-NH2
Mechanism of Action
Melanotan II (MT-2) is a synthetic cyclic heptapeptide analog of α-MSH (alpha-melanocyte stimulating hormone). It is a NON-SELECTIVE melanocortin receptor agonist — activating MC1R through MC5R, producing multiple simultaneous effects.
MC1R (TANNING): Activates melanocytes → tyrosinase upregulation → eumelanin synthesis → skin darkening. UV exposure accelerates the process but is not strictly required. Provides photoprotective darkening.
MC3R (METABOLISM): Energy homeostasis modulation.
MC4R (SEXUAL AROUSAL): Activation in hypothalamic paraventricular nucleus → central sexual arousal pathway (both men and women). This mechanism is vascular-independent — different from PDE5 inhibitors. Also mediates appetite suppression and nausea (area postrema).
MC5R (EXOCRINE): Sebaceous gland stimulation.
PT-141 (bremelanotide) was directly derived from MT-2 research — it was developed as a more targeted MC4R agonist for sexual dysfunction after MT-2's sexual effects were discovered.
The non-selectivity of MT-2 means ALL melanocortin effects occur simultaneously — tanning, sexual arousal, appetite suppression, and nausea are all part of the package.
Dosing Protocol
Low Dose
███ – ███ mcg/day
Standard Dose
███ mcg/day
High Dose
███ – ███ mcg/day
Dosing protocols are for paid members
Get exact dosing ranges, injection frequency, timing rationale, and reconstitution math.
Get Clinical Access — $79/moFrequency
Loading: daily or every other day for 2–3 weeks.
Half-Life
1 hour
Reconstitution Guide
Full reconstitution protocol with BAC water volumes, concentration math, and units-to-draw per dose is available on the Clinical plan.
Unlock reconstitution guide →Clinical Warnings
Non-selective — activates ALL melanocortin receptors.
Mole darkening — complicates skin cancer screening.
Nausea at higher doses.
Priapism risk in men.
NEVER use with melanoma history.
Blood pressure effects.
Facial flushing.
Not FDA approved.
Contraindications
Absolute
Melanoma or history of melanoma
Pregnancy
Pheochromocytoma
Relative Cautions
Many moles/nevi
Autoimmune conditions
Hypertension
Side Effect Profile
Mild
- ●Nausea
- ●Facial flushing
- ●Mild fatigue
- ●Spontaneous erections
Moderate
- ●Darkening of moles
- ●Headache
- ●Appetite suppression
- ●New nevi formation
Severe (Rare)
- ●Melanoma risk (theoretical)
- ●Severe nausea/vomiting
- ●Rhabdomyolysis (rare)
Synergistic Peptides
Common Stacks
PT-141
Research Status
MODERATE. PMID 9408315 (Wessells 1998): Erectile function double-blind RCT — first demonstration of central sexual arousal mechanism. Led to PT-141 development. Not FDA approved — PT-141 was approved instead.
Frequently Asked Questions
How does Melanotan II work?
Melanotan II (MT-2) is a synthetic cyclic heptapeptide analog of α-MSH (alpha-melanocyte stimulating hormone). It is a NON-SELECTIVE melanocortin receptor agonist — activating MC1R through MC5R, producing multiple simultaneous effects. MC1R (TANNING): Activates melanocytes → tyrosinase upregulation → eumelanin synthesis → skin darkening. UV exposure accelerates the process but is not strictly required. Provides photoprotective darkening. MC3R (METABOLISM): Energy homeostasis modulation. MC4R
What is the standard dose of Melanotan II?
Melanotan II dosing protocols are available with a ClinPep Clinical subscription. Dosing varies by indication and patient factors — consult a licensed healthcare provider. General frequency: Loading: daily or every other day for 2–3 weeks.
What is the half-life of Melanotan II?
The half-life of Melanotan II is 1 hour. This determines optimal dosing frequency and timing.
Who should not use Melanotan II?
Melanotan II is absolutely contraindicated in: Melanoma or history of melanoma; Pregnancy; Pheochromocytoma. Use with caution in: Many moles/nevi; Autoimmune conditions; Hypertension.
What are the side effects of Melanotan II?
Common mild side effects include: Nausea, Facial flushing, Mild fatigue, Spontaneous erections. Moderate effects: Darkening of moles, Headache, Appetite suppression, New nevi formation.
What peptides stack well with Melanotan II?
Melanotan II is commonly stacked with: PT-141.
How do you reconstitute Melanotan II?
Melanotan II is reconstituted with bacteriostatic water. Exact volumes, concentrations, and units-to-draw calculations are available in the ClinPep Clinical plan. Always follow your compounding pharmacy's instructions.
How long should you cycle Melanotan II?
Melanotan II cycle protocols vary by indication. Detailed cycle length, on/off schedules, and monitoring guidelines are available with ClinPep Clinical access. Consult your healthcare provider for personalized cycling guidance.
References & Citations
10 PubMed studies · 1 clinical trials
Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats in a model of chronic unpredictable stress.
Inozemtseva Ludmila S, Yatsenko Ksenia A, Glazova Natalya Yu, Kamensky Andrey A et al.. European journal of pharmacology. 2024
Current antidepressant therapy shows substantial limitations, and there is an urgent need for the development of new treatment strategies for depression. Stressful events and hyperactivity of the hypo
Recommended Tool Compounds for the Melanocortin Receptor (MCR) G Protein-Coupled Receptors (GPCRs).
Weirath Nicholas A, Haskell-Luevano Carrie. ACS pharmacology & translational science. 2024
The melanocortin receptors are a centrally and peripherally expressed family of Class A GPCRs with physiological roles, including pigmentation, steroidogenesis, energy homeostasis, and others yet to b
Therapeutic Strategies Against Metabolic Imbalance in a Male Mouse Model With 5-HT2CR Loss-of-Function.
Liu Hailan, Liu Zhaoxun, Wong HueyXian Kelly, Xu Nathan et al.. Endocrinology. 2024
The serotonin 2C receptor (5-HT2CR)-melanocortin pathway plays well-established roles in the regulation of feeding behavior and body weight homeostasis. Dysfunctions in this system, such as loss-of-fu
Melanocortin agonism in a social context selectively activates nucleus accumbens in an oxytocin-dependent manner.
Ford Charles L, McDonough Anna A, Horie Kengo, Young Larry J. Neuropharmacology. 2024
Social deficits are debilitating features of many psychiatric disorders, including autism. While time-intensive behavioral therapy is moderately effective, there are no pharmacological interventions f
Melanocortin receptor agonist melanotan-II microinjected in the nucleus accumbens decreases appetitive and consumptive responding for food.
Eliason Nicole L, Martin Lynne, Low Malcolm J, Sharpe Amanda L. Neuropeptides. 2022
Obesity is a major health problem worldwide. An understanding of the factors that drive feeding behaviors is key to the development of pharmaceuticals to decrease appetite and consumption. Proopiomela
Vasopressin neurons in the paraventricular hypothalamus promote wakefulness via lateral hypothalamic orexin neurons.
Islam Md Tarikul, Rumpf Florian, Tsuno Yusuke, Kodani Shota et al.. Current biology : CB. 2022
The sleep-wakefulness cycle is regulated by complicated neural networks that include many different populations of neurons throughout the brain. Arginine vasopressin neurons in the paraventricular nuc
CLIPSing Melanotan-II to Discover Multiple Functionally Selective hMCR Agonists.
Tomassi Stefano, Dimmito Marilisa Pia, Cai Minying, D'Aniello Antonia et al.. Journal of medicinal chemistry. 2022
The pleiotropic role played by melanocortin receptors (MCRs) in both physiological and pathological processes has stimulated medicinal chemists to develop synthetic agonists/antagonists with improved
Melanotan II User Experience: A Qualitative Study of Online Discussion Forums.
Gilhooley Eimear, Daly Selene, McKenna Dermot. Dermatology (Basel, Switzerland). 2021
Melanotan II (MT II) is a synthetic analogue of α-melanocyte-stimulating hormone that, via interaction with the melanocortin 1 receptor, induces skin hyperpigmentation. The unregulated acquisiti
Registered Clinical Trials
Melanotan II (MT-II) as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental Vitiligo
Symptom Indications
Full Clinical Access
Complete Melanotan II Protocol
Access reconstitution math, cycle guides, drug interaction checker, stack builder with contraindication analysis, symptom checker, and downloadable PDF handouts.
Secure payment powered by Stripe.
This information is for educational and research reference purposes only. ClinPep does not provide medical advice, diagnosis, or treatment recommendations. All protocols should be reviewed by a licensed healthcare provider.