Everything below concerns melanotan-2. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-04-26. Numbers and descriptions here follow the published literature rather than marketing material.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Belongs to the melanocortin agonist family |
| Key substitutions | Nle4 and D-Phe7 | Improve resistance to enzymatic degradation |
| Molecular formula | C50H69N15O9 | Approximately 1024 g/mol |
| Regulatory status | Not approved as a medicine | Distributed as a research chemical |
| Common synonyms | Melanotan II, MT-II, MT-2 | Spelling varies across sources |
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
=== Biosynthesis === Creatine is not an essential nutrient. It is an amino acid derivative, naturally produced in the body from the amino acids glycine and arginine, with an additional requirement for S-adenosyl methionine (a derivative of methionine) to catalyze the transformation of guanidinoacetate to creatine. In the first step of the biosynthesis, the enzyme arginine:glycine amidinotransferase (AGAT, EC:2.1.4.1) mediates the reaction of glycine and arginine to form guanidinoacetate. This product is then methylated by guanidinoacetate N-methyltransferase (GAMT, EC:2.1.1.2), using S-adenosyl methionine as the methyl donor. Creatine itself can be phosphorylated by creatine kinase to form phosphocreatine, which is used as an energy buffer in skeletal muscles and the brain. A cyclic form of creatine, called creatinine, exists in equilibrium with its tautomer and with creatine.
Prince Alexander Ferdinand Albrecht Achilles Wilhelm Joseph Viktor Carl Feodor of Prussia (26 December 1912 – 12 June 1985), who married Armgard Weygand on 19 December 1938. They had one son, Prince Stephan Alexander Dieter Friedrich of Prussia (1939–1993); he had one daughter, Princess Stephanie Victoria-Louise of Prussia (born 1966).
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to form images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR) , which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. In the early 1970s, it was demonstrated by R. Damadian, C.F. Hazlewood and D.C. Chang that measurement of NMR relaxation times can be used to detect cancer. Soon after that, P.C. Lauterbur proposed to use a magnetic field gradient to generate the NMR image in a 2-D plane. Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, although "open" MRI designs mostly relieve this. Additionally, implants and other non-removable metal in the body can pose a risk and may exclude some patients from undergoing an MRI examination safely. MRI was originally called NMRI (nuclear magnetic resonance imaging), but "nuclear" was dropped to avoid negative associations.
Sources: en.wikipedia.org
The World Health Organization stresses that the disease is a societal responsibility and that these dietary choices should be made the most available, affordable, and accessible options. Medications can be used, along with a suitable diet, to reduce appetite or decrease fat absorption. If diet, exercise, and medication are not effective, a gastric balloon or surgery may be performed to reduce stomach volume or length of the intestines, leading to earlier satiety, or a reduced ability to absorb nutrients from food. Metabolic surgery promotes weight loss not only by reducing caloric intake but also by inducing sustained changes in the secretion of gut hormones involved in appetite and metabolic regulation. Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children. In 2022, over 1 billion people lived with obesity worldwide (879 million adults and 159 million children), representing more than double the adult cases (and four times higher than cases among children) registered in 1990. 12.1% of the worlds adult population was obese in 2012 to 16.2% in 2024, with projections of 18.6% by 2030. Obesity is more common in women than in men. Obesity is often stigmatized in many parts of the world. Conversely, some cultures, past and present, have a favorable view of obesity, seeing it as a symbol of wealth and fertility. The World Health Organization, the US, Canada, Japan, Portugal, Germany, the European Parliament and medical societies (such as the American Medical Association) classify obesity as a disease.
=== Peptides work === Pert published over 250 scientific articles on peptides and their receptors and the role of these neuropeptides in the immune system. She held a number of patents for modified peptides in the treatment of psoriasis, Alzheimer's disease, chronic fatigue syndrome, stroke and head trauma. One of her modified peptides, Peptide T, had been considered for the treatment of AIDS and neuroAIDS. A placebo-controlled, three-site, 200+ patient NIH-funded clinical trial which was principally concerned with possible neurocognitive improvements, was conducted between 1990 and 1995. It was found that the effect of Peptide T was not significantly different from that of placebo on the primary end points of the study - various aspects of brain function. However, Peptide T was associated with improved performance (memory and learning) in the subgroup of patients with more severe cognitive impairment. A long-delayed analysis of antiviral effects from the NIH study showed peripheral viral load (combined plasma and serum) was significantly reduced in the DAPTA-treated group. An eleven-person study of Peptide T effects on cellular viral load showed reductions in infected monocyte reservoir to undetectable levels in most of the patients. Pert was developing orally active peptide anti-inflammatory treatments for pain and Alzheimer's Disease and studies for treatment of HIV persistent viral reservoirs.
=== CD200 === Basophil function is inhibited by CD200. Herpesvirus-6, herpesvirus-7, and herpesvirus-8 produce a CD200 homolog which also inhibits basophil function. This suggests that basophils may play a role in the immune response to these viruses. The role of basophils in the immune response to these viruses is further supported by findings that the CD200 receptor is expressed more frequently in basophils than in other circulating leukocytes.
Sources: en.wikipedia.org
It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.
No regulatory agency has approved it for any indication. It is encountered as a research chemical sold outside pharmaceutical supply chains. Products marketed this way are not subject to the manufacturing and labeling requirements that apply to approved drugs.
Reports describe increased skin pigmentation as well as side effects such as nausea, flushing, and changes to existing moles. Much of the evidence comes from small studies and case reports rather than large trials. The long-term safety profile is therefore uncertain.
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.