This is a working overview of Bremelanotide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-27. Anything still debated is marked as such rather than presented as settled.
Development of the peptide passed through several delivery formats, including an intranasal version tested in early trials and an injectable version that entered later clinical study. Regulatory approval for a subcutaneous product in the United States was granted in 2019 after review of controlled trials in premenopausal women. Outside the clinic, the compound circulates in research and non-pharmaceutical markets under its code name, where identity and purity vary considerably between suppliers. Synonyms appearing across technical literature include bremelanotide, PT-141, and Palatin 141.
PT-141 is the research designation for bremelanotide, a synthetic cyclic heptapeptide developed as a melanocortin receptor agonist. The peptide contains seven amino acids with an internal lactam bridge that constrains the backbone into a stable ring. Cyclisation of this kind improves resistance to enzymatic degradation relative to linear analogues. The compound was first explored for effects on melanin production, because several melanocortin receptors influence pigmentation. Its later association with sexual desire emerged from observations made during that early work, and the molecule became the subject of a separate development programme.
Bremelanotide is a moderately large peptide with a molecular mass near 1025 daltons. In lyophilised form it appears as a white to off-white powder and is freely soluble in water and other polar solvents. The intact lactam ring is essential for receptor affinity, while linearised fragments bind far more weakly. Solutions are sensitive to extremes of pH and to prolonged exposure to light and heat, so handling typically involves buffered conditions and cold storage. Its short plasma half-life reflects rapid distribution and clearance rather than chemical breakdown inside the vial.
Across literature and commercial listings, the substance appears under several names, including bremelanotide, PT-141, and various brand designations. A CAS registry number provides a unique identifier for the compound, aiding retrieval from chemical databases. Synonym lists may also contain early development codes and descriptive chemical names. When consulting sources, researchers need to confirm that the cited names refer to the same molecular structure to avoid confusion. Naming consistency matters especially when comparing analytical data across publications.
PT-141 is a synthetic cyclic heptapeptide whose development code is bremelanotide. It belongs to the class of melanocortin receptor agonists and acts by mimicking endogenous peptide hormones. The compound originated from research on melanotan II, where investigators exploring derivatives found distinct pharmacological features. Unlike the parent compound, PT-141 showed effects on pathways related to sexual desire and function in early studies, prompting its development as a separate candidate. Its molecular design aimed to separate receptor activity from pigmentary effects.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Cyclic heptapeptide | Synthetic melanocortin analogue |
| Molecular formula | C50H68N14O10 | Corresponds to a mass near 1025 daltons |
| Appearance | White to off-white powder | Lyophilised solid before reconstitution |
| Solubility | Soluble in water and polar solvents | Poor solubility in nonpolar media |
| Common synonyms | Bremelanotide, PT-141 | Code name and international name used interchangeably |
Clinical research typically uses randomised, double-blind, placebo-controlled designs. The most common primary endpoint is the desire domain score of the Female Sexual Function Index, sometimes paired with a distress measure. Secondary outcomes include arousal, satisfaction, and event-based counts of satisfying sexual episodes. Across trials, average improvements are modest and individual responses vary widely. Whether benefits persist beyond a few months, and whether they depend on baseline hormone status, remain open questions rather than settled findings.
Melanocortin receptors form a family of five G-protein-coupled receptors designated MC1 through MC5. Bremelanotide binds most strongly at MC4R and MC1R, with weaker activity reported at MC3R and MC5R. MC4R is expressed in hypothalamic nuclei that coordinate energy balance and aspects of sexual behaviour. The prevailing interpretation is that central MC4R activation, rather than peripheral vascular effects alone, drives the reported changes in desire. This account remains partly inferential, since direct receptor-level measurement in living humans is not practical.
After subcutaneous administration, plasma concentrations rise within roughly thirty minutes and the elimination half-life is short, on the order of two to three hours. Reported physiological responses include transient increases in blood pressure and nausea, which tended to diminish with repeated dosing in trial settings. Because the peptide clears quickly, effects are not expected to persist long after a dose. Absorption from non-injected routes is poorly characterised, and nasal delivery produced variable plasma levels in older work.
Bremelanotide acts as a non-selective agonist at melanocortin receptors, with reported activity at MC1R, MC3R, MC4R and MC5R. The proposed basis for its central effects is activation of MC4R populations in the hypothalamus, a region associated with appetite and reproductive signalling. Because the peptide carries a net positive charge and polar side chains, it does not cross biological membranes freely, which is one reason oral administration is not the standard route. Effects generally appear within an hour of parenteral administration and are described as centrally mediated rather than peripheral.
Bremelanotide, developed under the code PT-141, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone. Its structure is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, with a lactam bridge joining the aspartate and lysine side chains. The molecule has the formula C50H68N14O10 and a monoisotopic mass near 1025 daltons. It is commonly prepared as the acetate salt and appears as a white to off-white lyophilised powder in solid form. The free acid is the pharmacologically relevant species, while the counter-ion improves handling and dissolution.
Early research on PT-141 grew out of work on melanotan II, a related cyclic peptide studied for pigmentation. Investigators observed that centrally acting melanocortin agonists also influenced sexual behaviour in animal models, and the programme shifted toward that endpoint. A nasal formulation was evaluated in clinical trials but showed inconsistent absorption, and later studies used subcutaneous administration instead. Regulatory approval in the United States followed in 2019 for a defined population of premenopausal women with acquired, generalised hypoactive sexual desire disorder. That approval was specific to that group rather than a broad indication.
Aminosalicylic acid was introduced to clinical use in 1944. It was the second antibiotic found to be effective in the treatment of tuberculosis, after streptomycin. PAS formed part of the standard treatment for tuberculosis prior to the introduction of rifampicin and pyrazinamide. Its potency is less than that of the current five first-line drugs (isoniazid, rifampicin, ethambutol, pyrazinamide, and streptomycin) for treating tuberculosis and its cost is higher, but it is still useful in the treatment of multidrug-resistant tuberculosis. PAS is always used in combination with other anti-TB drugs. 4-Aminosalicylic acid has also been used in the treatment of inflammatory bowel disease (ulcerative colitis and Crohn's disease), but has been superseded by other drugs such as sulfasalazine and mesalazine. 4-Aminosalicylic acid has been investigated for the use in manganese chelation therapy, and a 17-year follow-up study shows that it might be superior to other chelation protocols such as EDTA.
argon (E938), a inert gas used for canned products helium (E939), a inert gas used for canned products nitrogen (E941), a nonreactive packaging gas and propellant carbon dioxide (E290), a nonreactive packaging gas and propellant Specific kinds of packaging gases are aerosol propellants. These process and assist the ejection of the product from its container. chlorofluorocarbons known as CFC (E940 and E945), now rarely used because of the damage that they do to the ozone layer: dichlorodifluoromethane (E940) chloropentafluoroethane (E945) nitrous oxide (E942), used for aerosol whipped cream canisters (see Nitrous oxide: Aerosol propellant) octafluorocyclobutane (E946) These must be used with caution as they may have adverse effects when exposed to certain chemicals. They will cause oxidisation or contamination to certain types of materials. oxygen (E948), used e.g. for packaging of vegetables hydrogen (E949)
44. Adv Gerontol. 2004;13:90-3. [Effect of epitalon on the immunity and hemostasis in hypophysectomized chicken and old hens]. [Article in Russian] Kuznik BI, Pateiuk AV, Khavinson VKh, Malinin VV. Neonatal hypophysectomy in chicken, as well as that in old hen has been established to entail in 1,5 months after surgery cellular and humoral immunity disturbances, pronounced hypercoagulation and fibrinolysis depression. Administration of Epitalon (Ala-Glu-Asp-Gly) to a large extent eliminates revealed shifts. This effect appeared to be stronger in neonatally hypophysectomized chicken than in old hens.
In Brazil, the Aeronautical Accidents Investigation and Prevention Center (CENIPA) was established under the auspices of the Aeronautical Accident Investigation and Prevention Center, a Military Organization of the Brazilian Air Force (FAB). The organization is responsible for the activities of aircraft accident prevention, and investigation of civil and military aviation occurrences. Formed in 1971, and in accordance with international standards, CENIPA represented a new philosophy: investigations are conducted with the sole purpose of promoting the "prevention of aeronautical accidents". In Canada, the Transportation Safety Board of Canada (TSB), is an independent agency responsible for the advancement of transportation safety through the investigation and reporting of accident and incident occurrences in all prevalent Canadian modes of transportation – marine, air, rail and pipeline. In China, the Civil Aviation Administration of China (CAAC) is solely responsible for all air investigations and safety inside the country after the split from the formal CAAC Airlines.
C-5 sterol desaturase couples sterol oxidation to the oxidation of NAD(P)H and the reduction of molecular oxygen. Either NADH or NADPH can be used; in the model plant species Arabidopsis thaliana C-5 sterol desaturase catalyzes the reaction twice as fast with NADH while in S. cerevisiae the enzyme has little preference. The precise details of the reaction have been thought to vary between mammals and yeast. However, the enzymes do share a conserved cluster of histidine residues, which when mutated (in A. thaliana) dramatically reduce or eliminate enzyme activity, suggesting the involvement of a coordinated iron cation in the mechanism. Mutagenesis studies suggest that in A. thaliana threonine 114 (which is a serine in humans, mice, and yeast) may help to stabilize the enzyme-substrate complex. Rahier has proposed a reaction mechanism in which an iron-coordinated oxygen abstracts a hydrogen from the substrate leading to a radical intermediate.
Sources: en.wikipedia.org
Assessment of kidney function occurs in different ways, using the presence of symptoms and signs, as well as measurements using urine tests, blood tests, and medical imaging. Functions of a healthy kidney include maintaining a person's fluid balance, maintaining an acid-base balance; regulating sodium and other electrolytes; clearing toxins; regulating blood pressure; and regulating hormones, such as erythropoietin; and activation of vitamin D. The kidney is also involved in maintaining blood pH balance.
It is a bioactive sphingoid which derives from the sphinganine. It is formed by a sphingoid and an amino alcohol and it constitutes the conjugated base of 1-deoxymethylsphinganine (1+). Its role is accepting a hydron from a donor via its organic amino compound; it is a Brønsted base. It is also known as deoxymethyl-SA, (2R)-1-aminoheptadecan-2-ol and 1-desoxymethylsphinganine. The molecular weight of this compound is 271,48 g/mol and its molecular formula is C17H37NO, which means it has 17 carbons. In relation to its appearance, it has a powder form. Other physical and chemical properties are not certainly known.
In the UK, a House of Commons Select Committee on Environment, Food and Rural Affairs report on the horse meat incident was not critical of UK or Irish producers. It expressed concern that horsemeat contamination resulted from fraud and other criminal activity across the EU. Chair of the Committee, Anne McIntosh MP, said: "The evidence suggests a complex network of companies trading in and mislabelling beef or beef products which is fraudulent and illegal." The second major UK report on the horse meat incident was conducted by Professor Chris Elliott, the Director of the Institute for Global Food Security at Queen's University Belfast. In his independent report, he argues that food crime was at the heart of the horsemeat incident and makes a range of suggestions for how this could be tackled. "Industry, government and enforcement agencies should, as a precautionary principle, always put the needs of consumers above all other considerations, and this means giving food safety and food crime prevention—i.e. the deterrence of dishonest behaviour—absolute priority over other objectives."
In collaboration with the Academic Medical Center in Amsterdam, Inreda Diabetic B.V. has developed a closed loop system with insulin and glucagon. The initiator, Robin Koops, started to develop the device in 2004 and ran the first tests on himself. In October 2016 Inreda Diabetic B.V. got the ISO 13485 license, a first requirement to produce its artificial pancreas. The product itself is called Inreda AP, and soon made some highly successful trials. After clinical trials, it received the CE marking, noting that it complies with European regulation, in February 2020. In October 2020 the health insurance company Menzis and Inreda Diabetic then started a pilot with 100 patients insured by Menzis. These are all patients that face very serious trouble in regulating their blood glucose levels. They now use the Inreda AP instead of the traditional treatment. Another large scale trial with the Inreda AP was set up in July 2021, and should determine whether Dutch health insurance should cover the device for all their insured. A smaller improved version of the Inreda AP is scheduled for release in 2023.
Although it is a relatively immature area of research, it appears that heterotrimeric G-proteins may also take part in non-GPCR signaling. There is evidence for roles as signal transducers in nearly all other types of receptor-mediated signaling, including integrins, receptor tyrosine kinases (RTKs), cytokine receptors (JAK/STATs), as well as modulation of various other "accessory" proteins such as GEFs, guanine-nucleotide dissociation inhibitors (GDIs) and protein phosphatases. There may even be specific proteins of these classes whose primary function is as part of GPCR-independent pathways, termed activators of G-protein signalling (AGS). Both the ubiquity of these interactions and the importance of Gα vs. Gβγ subunits to these processes are still unclear. There are two principal signal transduction pathways involving the G protein-linked receptors: the cAMP signal pathway and the phosphatidylinositol signal pathway.
Sources: en.wikipedia.org
PT-141 is a laboratory code for bremelanotide, a synthetic peptide that activates melanocortin receptors. It has been developed both as an injectable pharmaceutical product and as a research chemical. The two contexts differ sharply in how identity, purity, and dosing are controlled.
It is neither a steroid nor a naturally occurring human hormone. Bremelanotide is a manufactured peptide that mimics part of the melanocortin signalling system by binding receptor proteins. Its effects come from receptor activation, not from replacing a circulating hormone.
The internal lactam bridge locks the peptide into a defined shape, which raises receptor affinity and slows enzymatic breakdown. Linear versions of the same sequence are less stable and bind more weakly. Ring geometry is therefore central to how the molecule behaves in the body.
It belongs to the melanocortin receptor agonist family of peptides. Its cyclic structure distinguishes it from linear peptides and shapes its receptor binding profile.