Everything below concerns lyophilised powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic cyclic heptapeptide | Analog of alpha-MSH with an internal lactam bridge |
| Molecular weight | Approximately 1024 daltons | Free base value; salt forms differ |
| Appearance | White to off-white powder | Usually supplied as a lyophilized solid |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar solvents |
| Typical storage | −20 °C, dry, protected from light | Repeated freeze-thaw cycles degrade peptides |
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
=== STF === West Bengal government created new directorate of the Special Task Force under West Bengal Police. The Special Task Force (STF) of West Bengal, formed around three years ago, to combat modern urban organized crimes - terrorism, organized gangs, illegal arms, ammunition, drugs and fake currency across the state is all set to get a police station of its own and a designated court.
== Further reading == Lin, Y.; Zou, J.; Yang, W.; Li, C. Q. (2018). "A Review of Recent Advances in Research on PM2.5 in China". International Journal of Environmental Research and Public Health. 15 (3): 438. Bibcode:2018IJERP..15..438L. doi:10.3390/ijerph15030438. PMC 5876983. PMID 29498704. Abdel Hameed, A. A.; Yasser, I. H.; Khoder, I. M. (2004). "Indoor air quality during renovation actions: a case study". Journal of Environmental Monitoring. 6 (9): 740–744. Bibcode:2004JEnMo...6..740A. doi:10.1039/b402995j. PMID 15346177.
WHO referred to the incident as one of the largest food safety events it has had to deal with, and stated it would be difficult to restore the confidence of Chinese consumers in baby formula. It saw regulation failing to keep pace with the rapid development of the food and industrial production as opening the gates to all types of misbehaviour and malfeasance. The spokesman said the scale of the problem proved it was "clearly not an isolated accident, [but] a large-scale intentional activity to deceive consumers for simple, basic, short-term profits". WHO Director-General Margaret Chan reminded Chinese mothers that breastfeeding was the best way to provide nutrition to infants while avoiding a risk of melamine exposure. She noted that the scandal showed "the impact and power of globalisation" in food distribution and highlighted "the importance of seamless cooperation from farm to consumer".
=== Plant === Plant steroids include steroidal alkaloids found in Solanaceae and Melanthiaceae (specially the genus Veratrum), cardiac glycosides, the phytosterols and the brassinosteroids (which include several plant hormones).
Sources: en.wikipedia.org
The UPMC Mercy South Side Outpatient Center, formerly UPMC South Side hospital, is a 209,000-square-foot (19,400 m2) urgent care and outpatient facility serving the South Side neighborhood of Pittsburgh. It is one of several UPMC outpatient medical facilities serving various communities throughout the region.
Temporary halogenation with bromine to a trans‑1,2‑dibromoalkane: the regeneration of the alkene then follows with preservation of conformation via elemental zinc or with titanocene dichloride. Protection through a Diels-Alder reaction: the transformation of an alkene with a diene leads to a cyclic alkene, which is nevertheless similarly endangered by electrophilic attack as the original alkene. The cleavage of a protecting diene proceeds thermically, for the Diels-Alder reaction is a reversible (equilibrium) reaction.
One non-blinded non-randomized study determined the effectiveness of emoxypine in 205 patients with clinical manifestations of lumbosacral radiculopathy (LSR). Patients were divided into two groups, and further were divided into subgroups depending on the presence of motor disturbances. All patients received a course of conventional medical treatment and physiotherapy; main group additionally received emoxypine. Thereafter, clinical-neurological control of long-term results of treatment in subgroups of patients was performed. The results showed that the use of emoxypine in the combined therapy of patients with LSR led to significant and persistent reduction of severity of pain syndrome and rapid recovery of function of spinal roots and peripheral nerves compared with conventional therapy. However, these studies are primary research, and the effectiveness or purported pharmaceutical efficiency of emoxypine has not yet been validated through a meta analysis or systematic review.
== Development == Samidorphan has been investigated for the treatment of alcoholism and cocaine addiction by its developer, Alkermes, showing similar efficacy to naltrexone, but possibly with reduced side effects. It has attracted much more attention as part of the combination product (buprenorphine/samidorphan), where samidorphan is combined with the mixed μ-opioid receptor (MOR) weak partial agonist and κ-opioid receptor (KOR) antagonist buprenorphine, as an antidepressant. Buprenorphine has shown antidepressant effects in some human studies, thought to be because of its antagonist effects at the KOR, but has not been further developed for this application because of its MOR agonist effects and consequent abuse potential. By combining buprenorphine with samidorphan to block the MOR agonist effects, the combination acts more like a selective KOR antagonist, and produces only antidepressant effects, without typical MOR effects such as euphoria or substance dependence being evident. Samidorphan was also studied in combination with olanzapine, (olanzapine/samidorphan), for use in schizophrenia. A Phase III study found that the addition of samidorphan to olanzapine significantly reduced weight gain compared to olanzapine alone, and the combination was approved for the treatment of schizophrenia and bipolar disorder by the FDA in May 2021, under the brand name Lybalvi.
The thyroid gland is located in the front of the neck, in front of the thyroid cartilage, and is shaped like a butterfly, with two wings connected by a central isthmus. Thyroid tissue consists of follicles with a stored protein called colloid, containing thyroglobulin, a precursor to other thyroid hormones, which are manufactured within the colloid. The thyroid hormones increase the rate of cellular metabolism, and include thyroxine (T4) and triiodothyronine (T3). Secretion is stimulated by the thyroid-stimulating hormone, secreted by the anterior pituitary. When thyroid levels are high, there is negative feedback that decreases the amount of Thyroid-stimulating hormone secreted. Most T4 is converted to T3 (a more active form) in the target tissues. Calcitonin, produced by the parafollicular cells (C cells) of the thyroid gland in response to rising blood calcium levels, depresses blood calcium levels by inhibiting bone matrix resorption and enhancing calcium deposit in bones. Excessive secretion cause hyperthyroidism and deficiency cause hypothyroidism.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.
Melanotan-1, also called afamelanotide, is a shorter linear analog with a different amino acid sequence and no lactam ring. It has been evaluated in formal clinical programs, while melanotan-2 has not. The two are distinct molecules and are not interchangeable.
No. Bremelanotide is a related but distinct cyclic peptide that reached approved status for one specific clinical indication. Melanotan-2 is a separate molecule with its own sequence and properties. Shared ancestry in the melanocortin family does not make them the same substance.
The dry powder is more stable during transport and storage than a solution. It also allows a known amount of material to be reconstituted at a chosen concentration.