cyclic heptapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-04-19. Numbers and descriptions here follow the published literature rather than marketing material.
Reversed-phase high-performance liquid chromatography is the routine method for purity assessment. Peptides absorb near 214 nm because of the peptide bond, and a gradient of acetonitrile in water separates the intact peptide from deletion sequences, oxidised products, and earlier-eluting fragments at neutral pH. Electrospray ionisation mass spectrometry provides an orthogonal check: the measured mass must agree with the theoretical value. Amino acid analysis and peptide mapping confirm structure but are used less often. Reference standards remain scarce because the peptide is not described in any pharmacopoeia.
Regulatory treatment varies by country. In the United States the peptide is not approved as a medicine, and products offered for human use may be treated as unapproved new drugs; some states also restrict sale. Australia, the United Kingdom, and European Union member states apply comparable restrictions to unapproved peptide products. Border agencies have seized shipments labelled as research chemicals. Classification may change over time, and the legal position for personal importation is not clearly settled in most published guidance.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage 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.
| Property | Value | Notes |
|---|---|---|
| Lyophilised storage | −20 °C, dry, protected from light | Vials are sealed and allowed to reach room temperature before opening |
| Reconstituted storage | 2 to 8 °C, protected from light | Short-term holding; avoid repeated freeze-thaw cycles |
| Reconstitution solvent | Water for injection or bacteriostatic water | Added slowly along the vial wall to reduce foaming and shear |
| Purity measurement | RP-HPLC with area normalisation | Acetonitrile-water gradient monitored at roughly 214 nm |
| Identity confirmation | Electrospray ionisation mass spectrometry | Observed mass compared against the calculated peptide mass |
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
Melanotan II is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, corresponding to a molecular formula of C50H69N15O9 and a monoisotopic mass near 1024 daltons. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, a peptide hormone produced by cleavage of proopiomelanocortin. A lactam bridge between the aspartate and lysine side chains closes the ring, and the C-terminal amide removes a free carboxyl group. Both modifications increase resistance to enzymatic degradation compared with the linear parent hormone. Four substitutions distinguish it from afamelanotide, the linear analogue studied under the name melanotan I.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
Published pharmacokinetic information is limited and comes mainly from small studies rather than registrational trials. Plasma half-life is usually described as short, on the order of tens of minutes, followed by rapid tissue distribution and clearance of the intact peptide. Metabolites and low concentrations of parent compound have been reported in urine, a detail relevant to anti-doping and forensic testing. Whether repeated exposure changes receptor sensitivity or clearance over time remains an open question. Values differ noticeably between analytical assays, so published numbers should be read as approximate rather than definitive.
== History == OFM was developed and is manufactured by Aroa Biosurgery Limited (New Zealand, formerly Mesynthes Limited, New Zealand) and was first patented in 2008 and described in the scientific literature in 2010. OFM is manufactured from sheep rumen tissue, using a process of decellularization to selectively remove the unwanted sheep cells and cell components to leave an intact and functional extracellular matrix. OFM comprises a special layer of tissue found in rumen, the propria submucosa, which is structurally and functionally distinct from the submucosa of other gastrointestinal tissues. OFM was first cleared by the FDA in 2009 for the treatment of wounds. Since 2008 there have been >70 publications describing OFM and its clinical applications, and over 6 million clinical applications of OFM-based devices.
Herringbone stitch secures the edges of a textile to a backing fabric. This stitch is also a flexible way to join more than one layer of fabric. Herrigbone stitch is similar to a cross stitch with interlocking stitches. Slip-stitch is used to secure a backing fabric and is nearly invisible on the right side of the fabric. Couching is the most commonly used stitching method in textile stabilization. Torn, frayed, or weak areas can be secured to a support fabric with couching. Generally, a 5mm stitch spacing will give stability and be quicker to stitch than a closer spacing. Darning stitch is used to cover areas of loss and prevent further degradation. Laid couching is a long straight stitch, held in place with short perpendicular stitches. Brick couching is a short stitch placed over one or several threads and sewn in a brick-work like pattern. Thread types cotton thread is the most commonly used thread for stabilizing textiles. Fine polyester is also acceptable.
23 October A significant breakthrough in treating cervical cancer is reported by University College London, with participants in a Phase III trial seeing a 35% reduction in the risk of both mortality or the disease returning. The study used a combination of existing, cheap drugs ahead of usual radiotherapy treatment. The Royal Mint unveil a special Christmas 50 pence coin, celebrating the 1978 picture book The Snowman by Raymond Briggs. British-Israeli Yosef Guedalia is named as another victim killed by Hamas in the 7 October attack. Sunak tells parliament the UK has judged the al-Ahli Arab Hospital explosion, which occurred on 17 October, was likely caused by "a missile, or part of one" fired from "within Gaza". COVID-19 in the UK: Hospitals ask visitors to wear face-coverings amidst a rise in COVID-19 cases. 24 October Office for National Statistics data shows that UK unemployment remained at 4.2% in the three months up to August 2023. A BBC investigation finds that UK authorities failed to act on multiple official warnings about an online forum promoting suicide connected to at least 50 UK deaths. Immigration Minister Robert Jenrick confirms that the UK government will stop using 50 hotels to accommodate asylum seekers by January 2024. Local officials subsequently warn that local authorities may be forced to pay for use of the hotels instead. The Financial Conduct Authority confirms that the cap on bankers' bonuses, introduced in 2014, will be lifted from 31 October as part of post-Brexit financial reforms.
=== Antibody-free protein detection === While protein detection with antibodies is still very common in molecular biology, other methods have been developed as well, that do not rely on an antibody. These methods offer various advantages, for instance they often are able to determine the sequence of a protein or peptide, they may have higher throughput than antibody-based, and they sometimes can identify and quantify proteins for which no antibody exists.
In the 1960s, Australia - particularly Queensland - launched the first awareness campaign on the dangers of ultraviolet (UV) radiation in the spirit of primary prevention. In the 1980s, many countries in Europe and overseas initiated similar UV protection campaigns. UV radiation has a thermal effect on the skin and eyes and can lead to skin cancer (malignant melanoma) and eye inflammation or cataracts. To protect the skin from harmful UV radiation, such as photodermatosis, acne aestivalis, actinic keratosis or urticaria solaris, normal clothing, special UV protective clothing (SPF 40-50) and high SPF sunscreen can be used. The Australian-New Zealand Standard (AS/NZS 4399) of 1996 measures new textile materials in an unstretched and dry state for the manufacture of protective clothing worn while bathing, especially by children, and for the manufacture of shading textiles (sunshades, awnings). The UV Standard 801 assumes a maximum radiation intensity with the solar spectrum in Melbourne, Australia, on January 1 of a year (at the height of the Australian summer), the most sensitive skin type of the wearer, and under wearing conditions. As the solar spectrum in the northern hemisphere differs from that in Australia, the measurement method according to the European standard EN 13758-1 is based on the solar spectrum of Albuquerque (New Mexico, USA), which corresponds approximately to that of southern Europe. To protect your eyes, wear sunglasses with UV protection or special goggles that also shield the sides to prevent snow blindness.
Sources: en.wikipedia.org
Only one Ambrosiella (A. cleistominuta from the xyleborine ambrosia beetle Anisandrus maiche) has ever been reported to produce sexual structures, and the rest (including A. roeperi) have been assumed to undergo exclusively clonal reproduction. All Ambrosiella produce translucent, flask-shaped conidiogenous cells (phialides) borne on non-fertile sporodochia (minute, dense cushions of nonreproductive hyphae holding up the fertile tissue). Conidia may arise from these phialides as chains – i.e., new spores are successively pushed out, with the newest growth closest to the original conidiogenous cell – or singly, as an aleurioconidium that ruptures the membrane of the mother cell and then remains a unique, differentiated terminal unit without any subsequent neighbors produced from the phialide. A. roeperi operates only through the latter mechanism, which is distinct from what is reported in A. beaveri, A. trypodendri, and A. hartigii (suggested to use the former, chain-like method).
=== Increased risk of depression === It has been claimed that insomnia causes depression and hypothesized that insomnia medications may help to treat depression. However, an analysis of data of clinical trials submitted to the Food and Drug Administration (FDA) concerning the drugs zolpidem, zaleplon, and eszopiclone found that these sedative hypnotic drugs more than doubled the risks of developing depression compared to those taking placebo pills. Hypnotic drugs, therefore, may be contraindicated in patients with or at risk of depression. Hypnotics were found to be more likely to cause depression than to help it. Studies have found that long-term users of sedative hypnotic drugs have a markedly raised suicide risk as well as an overall increased mortality risk. Cognitive-behavioral therapy (CBT) for insomnia, on the other hand, has been found to both improve sleep quality as well as general mental health.
== Medical uses == Cipaglucosidase alfa is a long-term enzyme replacement therapy used in combination with the enzyme stabilizer miglustat for the treatment of adults with late-onset Pompe disease (acid α-glucosidase [GAA] deficiency).
== Safe handling == Proper handling of affected or damaged materials prevents mold from spreading. Because mold spores are released into the air, it is recommended to wear an NIOSH-rated respirator before coming into contact with affected materials. Nitrile gloves should be worn to protect the skin from contact with mold. In extreme cases, a full-body hazmat suit may be required. Materials must always be treated on a surface that can be cleaned with bleach or on neutral, disposable materials such as unprinted newsprint.
People who have consumed ayahuasca report having mystical experiences and spiritual revelations regarding their purpose on earth, the true nature of the universe, and deep insight into how to be the best person they possibly can. Many people also report therapeutic effects, especially around depression and personal traumas. This is viewed by many as a spiritual awakening and what is often described as a near-death experience or rebirth. It is often reported that individuals feel they gain access to higher spiritual dimensions and make contact with various spiritual or extra-dimensional beings who can act as guides or healers. The experiences that people have while under the influence of ayahuasca are also culturally influenced. Westerners typically describe experiences with psychological terms like "ego death" and understand the hallucinations as repressed memories or metaphors of mental states. However, at least in Iquitos, Peru (a center of ayahuasca ceremonies), those from the area describe the experiences more in terms of the actions in the body and understand the visions as reflections of their environment, sometimes including the person who they believe caused their illness, as well as interactions with spirits.
Sources: en.wikipedia.org
Low temperature slows hydrolysis and oxidation, the two main routes by which the peptide backbone and side chains are modified. A lyophilised powder stored at −20 °C is more stable than one kept at room temperature, and once the material is dissolved the degradation rate rises, making refrigeration more important.
Liquid chromatography coupled to mass spectrometry is the most common approach because it combines a retention time with a mass measurement. A chromatographic peak alone cannot establish which peptide is present, so mass determination or amino acid analysis is used as an orthogonal confirmation alongside the separation.
This depends on buffer, pH, and concentration, and published stability data for this peptide are limited. In practice laboratories work through a refrigerated solution within a few weeks and discard samples that show cloudiness or visible particles. Freezing and thawing repeatedly is generally discouraged.
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.