The short version of PT-141 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-23 and is reviewed periodically as new material appears.
Compared with the related compound melanotan II, PT-141 shows markedly weaker activation of receptors tied to pigmentation. This difference stems from subtle structural variations that alter affinity distribution across receptor subtypes. Investigators propose that such selectivity produces a different side effect profile in specific applications. However, downstream consequences of prolonged receptor activation remain uncertain in the literature. Published studies do not fully agree on the duration of signaling pathway activity and the mechanisms of desensitization.
From a pharmacokinetic standpoint, the peptide is usually delivered by injection because oral bioavailability is very low; proteases in the digestive tract degrade it rapidly. After subcutaneous administration, plasma concentrations reach a peak within roughly one hour. Its elimination half-life is relatively short, with most reports placing it in the range of a few hours. Nasal formulations have also been examined, though absorption varies widely between individuals. Metabolism proceeds mainly through peptidase cleavage, and the resulting products are excreted by the kidneys.
PT-141 initiates cellular signaling by binding to specific subtypes within the melanocortin receptor family. These receptors belong to the G protein-coupled receptor superfamily, and activation raises intracellular cyclic adenosine monophosphate levels. This cascade ultimately influences neuronal circuits in the central nervous system that are associated with sexual desire and arousal. Research indicates the compound's action concentrates in hypothalamic regions rather than peripheral tissues, which helps explain some observed pharmacological features. The selectivity of receptor binding underlies its functional differences.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | Melanocortin receptors | Mainly the MC4R subtype |
| Route of administration | Injection | Typically subcutaneous |
| Time to peak | About 60 minutes | After subcutaneous dosing |
| Elimination half-life | Roughly 2 to 3 hours | Values vary across reports |
| Metabolic pathway | Peptidase hydrolysis | Cleared by the kidneys |
Clinical development proceeded through two routes of administration. An intranasal formulation advanced first, but variable absorption and tolerability problems led to a switch to subcutaneous injection. The United States Food and Drug Administration approved the subcutaneous product in 2019 for hypoactive sexual desire disorder in premenopausal women. Marketing rights subsequently changed hands, and commercial availability has fluctuated since approval. Use in men, in postmenopausal women, and in combination with other agents remains outside the approved label.
Outside the approved product, bremelanotide circulates as a research chemical sold by peptide vendors, often labelled PT-141. Such material is not manufactured under pharmaceutical quality standards, and independent testing has repeatedly found content that differs from the label. Analytical certificates supplied with a purchase are not strong evidence of purity because they are usually generated by the seller. Online discussion tends to blur the distinction between the approved drug and unregulated powder, which complicates interpretation of reported experiences.
PT-141 is the original development code for bremelanotide, a synthetic peptide first studied as a potential tanning and sexual-response agent in the 1990s. Researchers at a small American biotechnology firm designed it as a shortened analogue of melanotan II, which itself came from work on alpha-melanocyte-stimulating hormone. Early screening focused on pigmentation, but behavioural observations in animal models redirected attention toward sexual motivation. That shift made PT-141 one of the first melanocortin compounds investigated specifically for effects on desire rather than on skin colour.
Bremelanotide is a synthetic cyclic heptapeptide developed under the research code PT-141. The code reflects its position in an internal compound series rather than a chemical classification, and the name bremelanotide was later adopted for regulatory filings. Structurally it belongs to the melanocortin peptide family and shares a core sequence motif with alpha-melanocyte-stimulating hormone. The compound is supplied as an acetate salt in aqueous solution for injection. In reference literature it is indexed under both the code and the generic name, a dual listing that can complicate database searches.
Early work on melanocortin analogs in the 1980s and 1990s produced peptides intended to influence pigmentation and appetite. One of these, melanotan II, was observed to affect sexual desire as an incidental finding in self-administration reports. Researchers then pursued analogs with altered receptor selectivity and improved handling characteristics, and PT-141 emerged from that program in the late 1990s. The development path moved from dermatology and metabolism toward a central nervous system application, a shift that shaped both trial designs and the eventual label.
Regulatory review of bremelanotide concluded in 2019 with approval in the United States for a defined indication in premenopausal women. The reviewed formulation is a single-use prefilled autoinjector given subcutaneously, and its label carries cardiovascular monitoring language tied to blood pressure changes recorded during trials. Availability outside the approving jurisdiction varies, and in several countries the compound remains unapproved or is handled as a prescription-only item. Compounded and research-grade material also circulates, and it differs from the reviewed product in purity, characterization, and chain of custody.
Receptor activation in hypothalamic and limbic circuits is the mechanism most often cited for the observed effects on sexual desire. Signalling through MC4R couples to Gs proteins and raises intracellular cyclic AMP, which in turn modulates dopaminergic tone in reward-related pathways. Because the peptide reaches the central nervous system after subcutaneous administration, peripheral vascular changes are regarded as secondary rather than primary. The precise neural circuits that translate receptor occupancy into behavioural change remain incompletely mapped, and published accounts describe the pathway in general terms rather than as a fully resolved sequence.
Development began with intranasal formulations investigated for erectile dysfunction, but blood pressure elevation limited that route and prompted a switch to subcutaneous delivery. Clinical testing then shifted toward hypoactive sexual desire disorder in premenopausal women, and a subcutaneous product received United States approval in 2019. Later trials examined other populations with mixed results, and questions about effect size, durability and patient selection remain open in the peer-reviewed literature. Research interest continues in parallel with the broader melanocortin field, where several synthetic analogues are studied together.
PT-141 is the research code for bremelanotide, a cyclic heptapeptide derived from alpha-melanocyte-stimulating hormone. The molecule belongs to the melanocortin receptor agonist family and shows highest affinity for the MC4 receptor subtype, with weaker activity at MC1, MC3 and MC5. Its structure retains the core His-Phe-Arg-Trp sequence that defines melanocortin recognition, while cyclization and terminal modifications improve metabolic stability relative to the parent hormone. Early work classified the compound as a centrally acting agent rather than a peripherally acting vasodilator, which shaped subsequent development priorities.
== Research == Halliwell is known for his work on the control of free radicals in biological systems. His earliest research was in plants, where with Christine Foyer and others in 1976, he discovered the glutathione–ascorbate cycle (also known as the Foyer–Halliwell–Asada pathway) by which chloroplasts remove damaging hydrogen peroxide. He subsequently focused on the role of free radicals in human diseases, demonstrating the toxicity of the hydroxyl radical, a metabolite of superoxide, and investigated the involvement of metal ions, including iron and zinc, in this process, as well as the protective effect of their sequestration. He has also worked on reactive nitrogen species. He developed methods to measure free radical levels in vivo and to quantify the damage they cause to DNA. He has also researched dietary antioxidants. As of 2025, his research focuses on the role of free radicals and antioxidants in human disease, particularly Alzheimer's disease and other brain disorders. His interests include the characterisation of redox biomarkers for the identification of human diseases, molecular nutrition, the role of transition metal ions as promoters of radical reactions in vitro and in vivo, the development of drugs to prevent oxidative cell damage, the chemical nature of antioxidants in vivo, methods for the specific detection of reactive oxygen and reactive nitrogen species in vivo and their application to human disease, particularly stroke and neuro-degenerative diseases and ageing in humans and in the nematode Caenorhabditis elegans.
The pharmacology of 3-CMC is expected to be very similar to the pharmacology for other mephedrone analogs (methcathinones). These molecules interact with monoamine transporters, in particular the dopamine transporter (DAT), norepinephrine transporter (NET), and serotonin transporter (SERT) . The main function of these transporters is to terminate monoamine transmission by reuptake of the released neurotransmitters. Interaction of psychoactive drugs with the monoamine transporters inhibits this reuptake leading to an increase in the concentration of dopamine, norepinephrine and serotonin in the synaptic cleft. Specifically, 3-chloromethcathinone (3-CMC) and other ring-substituted methcathinone derivatives act as substrates for monoamine transporters MATs (and subsequently competitive inhibitors), through which they are actively translocated into the cytoplasm of the presynaptic nerve terminal. Once inside the cytosol, they interact with the vesicular monoamine transporter 2 (VMAT2) as substrates, disrupting the vesicular proton gradient and facilitating the collapse of synaptic vesicles. This causes the release of stored neurotransmitters into the cytoplasm. The resulting high concentration of cytosolic neurotransmitters subsequently triggers the reversal of MAT transport direction, leading to carrier-mediated efflux of the neurotransmitters into the synaptic cleft. Furthermore, simple ring-substituted cathinones contrast with traditional amphetamines by lacking significant affinity for the intracellular trace amine-associated receptor 1 (TAAR1).
Solvents can have a powerful effect on solubility, stability, and reaction rate. A change in solvent can also allow a chemist to influence the thermodynamic or kinetic control of the reaction. Reactions proceed at different rates in different solvents due to the change in charge distribution during a chemical transformation. Solvent effects may operate on the ground state and/or transition state structures. An example of the effect of solvent on organic reactions is seen in the comparison of SN1 and SN2 reactions. Solvent can also have a significant effect on the thermodynamic equilibrium of a system, for instance as in the case of keto-enol tautomerizations. In non-polar aprotic solvents, the enol form is strongly favored due to the formation of an intramolecular hydrogen-bond, while in polar aprotic solvents, such as methylene chloride, the enol form is less favored due to the interaction between the polar solvent and the polar diketone. In protic solvents, the equilibrium lies towards the keto form as the intramolecular hydrogen bond competes with hydrogen bonds originating from the solvent.
Sources: en.wikipedia.org
Lipedema is a chronic medical condition that is almost exclusively found in women and results in enlargement of both legs due to deposits of fat under the skin. It is characterized by bilateral, symmetrical buildup of fat in the legs, and sometimes arms and lower trunk (includes hips, buttocks, and abdomen). Women of any weight may be affected and the fat is resistant to traditional weight-loss methods like nutritional intervention, exercise, elevation, diuretics or bariatric surgery. The feet/hands are typically spared, presenting with a raised ridge or fold of fat, possibly a "cuff" at the wrists and ankles. In earlier stages, there may be a subtle, raised ridge or fold of fat instead of distinct cuffing and sometimes in the later stages, this increased adipose above the ankle/wrist can cause the appearance of a "cuff". Approximately 50% of people with Lipedema report pain in their fat. Other common symptoms include swelling, feelings of heaviness, and easy bruising in the affected areas. Over time mobility may be reduced, and due to reduced quality of life, people often experience depression. The cause is unknown but is believed to involve genetic and hormonal factors, lipedema onset is typically associated with periods of hormonal flux like puberty, pregnancy, or menopause and it often runs in families. Other conditions that may present similarly include lipohypertrophy, chronic venous insufficiency, and lymphedema. It is commonly misdiagnosed.
Niacin is incorporated into multi-vitamin and sold as a single-ingredient dietary supplement. The latter can be immediate or slow release. Nicotinamide is used to treat niacin deficiency and for supplementation because it does not cause the flushing adverse reaction seen with nicotinic acid. Nicotinamide may be toxic to the liver at doses exceeding 3 g/day for adults. One form of dietary supplement sold in the US is inositol hexanicotinate (IHN), also called inositol nicotinate. This is inositol that has been esterified with niacin on all six of inositol's alcohol groups. IHN is usually sold as "flush-free" or "no-flush" niacin in units of 250, 500, or 1000 mg/tablets or capsules. In the US, it is sold as an over-the-counter formulation, and often is marketed and labeled as niacin, thus misleading consumers into thinking they are getting an active form of the medication. While this form of niacin does not cause the flushing associated with the immediate-release products, there is not enough evidence to recommend IHN to treat hyperlipidemia.
== Etymology == Samaale, the last common ancestor of several Somali clans, is generally regarded as the source of the ethnonym Somali. Another theory is that the name is derived from the words soo and maal, which together mean "go" and "milk". This interpretation varies depending on region, with northern Somalis believing it means "camel's milk," and southern Somalis using the transliteration "sa maal", which refers to cow's milk. This is a reference to the pastoralism of the Somali people. Another proposed etymology is that the term Somali is derived from the Arabic ذوو مال, transliterated as dhawu māl and meaning "wealthy", again referring to Somali riches in livestock. The first written reference of the sobriquet Somali dates back to the early 15th century AD during the reign of Ethiopian Emperor Yeshaq I, who had one of his court officials compose a hymn celebrating a military victory over the Sultanate of Ifat. Simur was also an ancient Harari alias for the Somali people.
=== Treatment === Due to their agitated behavior and confused mental state, people with acute Datura poisoning or intoxication are typically hospitalized. Gastric lavage and the administration of activated charcoal can be used to reduce the stomach's absorption of the ingested material, and the drug physostigmine is used to reverse the effect of the poisons. Benzodiazepines can be given to calm the patient's agitation, and supportive care with oxygen, hydration and symptomatic treatment is often provided. Observation of the patient is indicated until the symptoms resolve, usually from 24 to 36 hours after ingestion of the Datura.
Sources: en.wikipedia.org
In August 2019, BASF agreed to sell its global pigments business to Japanese fine chemical company DIC for €1.15 billion ($1.28 billion) on a cash and debt-free basis. In September 2019, BASF signed an agreement with DuPont Safety & Construction, a subsidiary business unit of DuPont, to sell its ultrafiltration membrane business, Inge GmbH. According to BASF executives, Inge GmbH and its products fit better with DuPont and their business strategy. In February 2023, BASF announced that the company is planning to close one of its two ammonia factories at its site in Ludwigshafen, this comes as part of the companies plans to cut costs as the organisation has struggled with high energy costs. The result of the organisations plans will lead to increased production in China while resulting in the loss of 2,600 jobs. The Zhanjiang plant extends over 400 hectares and serves mainly the electronic industry and the automotive industry. In September 2023 BASF broke ground on its Zhanjiang syngas plant; the plant was due to be commissioned by 2025. In November 2023 the firm closed a $5bn 15-year investment deal in China, with Chinese banks. As of April 2023, BASF had 30 production facilities in China. CEO Martin Brudermüller held that Chinese revenue is essential to grow his European business in the face of "Europe’s high energy costs and stringent environmental rules."
==== 5.B Transmembrane 1-electron transfer carriers ==== 5.B.1 The Phagocyte (gp91phox) NADPH Oxidase Family 5.B.2 The Eukaryotic Cytochrome b561 (Cytb561) Family 5.B.3 The Geobacter Nanowire Electron Transfer (G-NET) Family 5.B.4 The Plant Photosystem I Supercomplex (PSI) Family 5.B.5 The Extracellular Metal Oxido-Reductase (EMOR) Family 5.B.6 The Transmembrane Epithelial Antigen Protein-3 Ferric Reductase (STEAP) Family 5.B.7 The YedZ (YedZ) Family 5.B.8 The Trans-Outer Membrane Electron Transfer Porin/Cytochrome Complex (ET-PCC) Family 5.B.9 The Porin-Cytochrome c (Cyc2) Family
== Clinical significance == The extracellular ADP-ribosyl-transferase ART2 is expressed only on T cells. T cell activation of P2X7 receptors can activate the T cells or cause T cell differentiation, can affect T cell migration or (at high extracellular levels of NAD+) can induce cell death by ART2.
Sources: en.wikipedia.org
It primarily activates specific subtypes in the melanocortin receptor family. These receptors are G protein-coupled and mediate signaling mainly within the central nervous system.
It activates pigmentation-related receptors more weakly. This selectivity is thought to alter its side effect profile.
Injection is the most common route. Nasal administration has been studied as well, though absorption varies considerably.
PT-141 was the development code used for bremelanotide during its preclinical and early clinical programme. The peptide is now generally referred to by its international nonproprietary name.