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Chemical Identity Of Bremelanotide — Explained

By Editorial Desk · published 2026-03-04 · last reviewed 2026-04-19 · Data

The short version of Bremelanotide fits in a sentence. The long version — which is the one that helps — is below.

This page was last updated on 2026-04-19 and is reviewed periodically as new material appears.

Chemical Identity of Bremelanotide

The molecular backbone consists of seven amino acid residues joined into a ring through a disulfide bridge. This cyclic conformation is critical for receptor binding. The sequence includes an acetylated N-terminus and an amidated C-terminus, modifications that improve resistance to enzymatic breakdown. One residue is in the D-configuration, a feature that further stabilizes the peptide against protease activity. Together, the ring structure and specific stereochemistry determine selectivity among melanocortin receptor subtypes.

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.

Bremelanotide Naming and Background

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.

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.

Pt-141 at a glance

PropertyValueNotes
Chemical classCyclic peptideMelanocortin receptor agonist family
Molecular weightApproximately 1025 DaFree base form
AppearanceWhite to off-white powderLyophilized product
SolubilitySoluble in waterAlso dissolves in polar organic solvents
Storage temperature-20 degrees CelsiusDry and protected from light

Receptor Pharmacology And Signalling

The peptide contains seven amino acids arranged in a ring, closed by a lactam bridge between a side-chain acid and an amine. This cyclic constraint holds the backbone in a defined conformation and increases resistance to enzymatic breakdown relative to linear analogs. N-terminal acetylation and a C-terminal amide further protect the molecule from exopeptidases. The result is a compound with a comparatively long circulation time for a small peptide. Structural modification of the bridge alters receptor affinity, which is one reason analogs in this family differ in their subtype preferences.

Whether the behavioral effect originates centrally, peripherally, or through both remains an active question. Animal experiments using receptor antagonists and site-specific injections point toward hypothalamic melanocortin circuits as a key locus, but translating those findings to humans is not straightforward. Blood pressure changes observed in trials suggest a vascular component that may be peripherally mediated. The relationship between receptor occupancy and reported effect has not been mapped in humans, and no validated biomarker predicts response. This gap makes it difficult to explain individual variability on pharmacological grounds alone.

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Receptor Pharmacology and Study Measures

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.

Analytical Characterisation and Storage Practice

The lyophilised solid is relatively stable when kept dry, protected from light and held at reduced temperature, commonly minus 20 degrees Celsius or lower for long-term storage. In solution the peptide is more vulnerable: tryptophan oxidation, hydrolysis of the lactam bridge and aggregation all become relevant over time, and the rate depends on pH, buffer composition and concentration. Repeated freeze-thaw cycles are generally avoided because they promote aggregation. Aqueous working solutions are typically prepared fresh or split into single-use aliquots to limit degradation before analysis.

Published studies differ in design, population and endpoint definition, so results are not always directly comparable across reports. Some trials used patient-reported measures of desire and distress, while others tracked physiological or behavioural outcomes. Questions that remain open include the durability of effects beyond short follow-up periods, the frequency of transient blood pressure elevation observed after administration, and whether a subtype-selective analogue could separate central effects from pigmentation-related activity. These points are usually framed as unresolved rather than settled in review literature.

Background from the literature

1993/2828) Finance Act 1993, section 211, (Appointed Day) Order 1993 (S.I. 1993/2831) A61 Trunk Road (Sheffield to Westwood Roundabout) (Detrunking) Order 1993 (S.I. 1993/2832) Building Societies (Aggregation) Rules 1993 (S.I. 1993/2833) Mid Glamorgan Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2834) Derwen National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2835) North Wales Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2836) Rhondda Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2837) Velindre National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2838) Gwynedd Community Health National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2839) Nevill Hall and District National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2840) Gwynedd Hospitals National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2841) Finance Act 1993, Chapter II, (Appointed Day) Order 1993 (S.I. 1993/2842) Payments to Redundant Churches Fund Order 1993 (S.I. 1993/2846) Ordination of Women (Financial Provisions) (Appeals) Rules 1993 (S.I. 1993/2847) East Anglian Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2848) Norfolk Ambulance National Health Service Trust Dissolution Order 1993 (S.I. 1993/2849) Combined Probation Areas (Cumbria) Order 1993 (S.I. 1993/2852) Combined Probation Areas (Greater Manchester) Order 1993 (S.I. 1993/2853) Employment Appeal Tribunal Rules 1993 (S.I.

Melarsoprol is an arsenic-containing medication used for the treatment of sleeping sickness (African trypanosomiasis). It is specifically used for second-stage disease caused by Trypanosoma brucei rhodesiense when the central nervous system is involved. For Trypanosoma brucei gambiense, eflornithine or fexinidazole is usually preferred. It is effective in about 95% of people. It is given by injection and is known by patients as "fire in the veins". Melarsoprol has a high number of side effects. Common side effects include brain dysfunction, numbness, rashes, and kidney and liver problems. About 1–5% of people die during treatment, although this is tolerated due to sleeping sickness itself having a practically 100% mortality rate when untreated. In those with glucose-6-phosphate dehydrogenase (G6PD) deficiency, red blood cell breakdown may occur. It has not been studied in pregnancy. While its mechanism of action is not fully understood, its covalent binding to trypanothione to form the toxic Mel T complex is thought to play a large role. Melarsoprol has been used medically since 1949. It is on the World Health Organization's List of Essential Medicines. In regions of the world where the disease is common, melarsoprol is provided for free by the World Health Organization. It is not commercially available in Canada or the United States. In the United States, it may be obtained from the Centers for Disease Control and Prevention, while in Canada it is available from Health Canada.

== Overdose == Only a single case of death due to mescaline, as peyote, has been described, and was likely due to asphyxiation by vomit rather than overdose or toxicity. However, there is also a case report of death due to jumping off a cliff while on a high dose of mescaline. In terms of extrapolated human lethal dose based on animal studies, the lethal dose of mescaline relative to a typical recreational dose has been estimated to be 24-fold or around 8,400 mg. However, mescaline has reportedly been taken by humans at doses of up to 8,000 mg without apparent toxic reactions. On the other hand, there is one unverified reported case of death due to a dose of 15,000 mg intravenously, which would equate to about 150 to 200 mg/kg. The median lethal dose (LD50) of mescaline has been determined in various animal species, with the values including 212 to 315 mg/kg i.p. in mice, 132 to 410 mg/kg i.p. in rats, 328 mg/kg i.p. in guinea pigs, 54 mg/kg in dogs, and 130 mg/kg i.v. in rhesus macaques, among others. It has been said that it would be difficult to take enough mescaline to cause death in humans. No deaths due to peyote use have been reported aside from the asphyxiation case. The highest dose of peyote known to have been taken is 90 dried buttons.

=== Tang and Song Dynasties === Material from the Tang and Song dynastyies (C. 618–1279 A.D) has also been excavated and analysed using ceramic petrography, revealing a plethora of information on trade links, as well as stylistic elements. The Tang dynasty in Shanghai is well-known for its three-colour pottery and its bright colours. After analysing the remains of these artefacts, scientists have been able to trace trade over time, and can now see that maritime trade was only established later on in its history. Qinglong town, the heart of the dynasty was a prosperous maritime economy, with extensive links to adjacent islands. Indeed, through analyses of pottery from Qinglong and surrounding areas, archaeologists have discovered that the Tang and Song Dynasties had trade links with Persians, Arabs, Hindu Indians, Malays, Bengalis, Sinhalese, Khmers, Chams, Jews and Nestorian Christians of the Near East - a vast trade network that helps to explain the wide array of colours and materials in their ceramics.

===== Phase I ===== Phenyl-hydroxy bromazolam, 4-hydroxy bromazolam, α-hydroxy bromazolam, and α-4-dihydroxy bromazolam. The formation of phenyl-hydroxy bromazolam was catalysed by CYP2B6, CYP2C19, and CYP3A4. 4-hydroxy bromazolam, as well as α-hydroxy bromazolam, were formed by CYP2B6, CYP2C19, CYP3A4, and CYP3A5. Additionally, CYP2C9 was found to catalyse the formation of α-hydroxy bromazolam as well. α-4-dihydroxy bromazolam was only found in incubations with CYP3A4.

Sources: en.wikipedia.org

Further detail

23 November Acoustic Nanoscale Separation via Wave-pillar Excitation Resonance (ANSWER) is demonstrated as a way of separating nanoparticles, especially small extracellular vesicles, from biofluids in under 10 minutes. A study reports phages have a large variety of CRISPR-Cas systems. They possibly may use them to edit hosts' genes and for competitive advantages, e.g. against rival phages. These systems could be useful for CRISPR-Cas gene editing. A study reports estimated contemporary prevalence and associations with belief in witchcraft around the world, which (in their data) varied between 9% and 90% between nations and is still a widespread element in worldviews globally. It also shows associations such as with low "innovative activity", lower life expectancy and high religiosity. Geneticists report that the fastest-evolved regions of the human genome, they call HAQERs, "rapidly diverged in an episodic burst" of positive selection prior to the human-Neanderthal split and identify over 1,500 such HAQERs that substantially distinguish humans from related other apes via datasets such as of HARs and experiments that use embryonic mouse brains.

Notable HPTLC devices such as the Linomat 5 and the Automatic TLC Sampler 4 (ATS 4) by CAMAG function very similarly by having the automated 'spray-on' sample application technique. This automated 'spray-on' technique is useful to overcome the uncertainty in droplet size and position when the sample is applied to the TLC plate by hand. Additionally, automation provides high resolution and narrow bands since the solvent evaporates immediately as the sample makes contact with the plate. One approach to automation has been the use of piezoelectric devices and inkjet printers for applying the sample. Alternatively, the Nanomat 4 and ATS 4 by CAMAG are manually operated where the sample is applied via spot application using a capillary pipette. Upon chromatographic detection, HPTLC plates are usually developed in saturated twin-trough chambers with filter paper for optimal outcomes. However, flat-bottom chambers and horizontal-development chambers are also used for specific compounds. A general mechanism for the HPTLC device goes as follows. A fitted filter paper is placed in the rear trough of the chamber and the mobile phase is poured through the rear trough to ensure complete solvent absorption of the filter paper. The chamber is then tilted to ~45° so both troughs are equal in solvent volume and left alone to equilibrate for ~20 mins. Finally, the HPTLC plate is placed in the chamber to develop. Between each sample reading, the mobile phase and filter paper are changed to ensure the best outcomes.

Progerin expression also leads to defects in the establishment of fibroblast cell polarity, which is also seen in physiological aging. To date, over 1,400 SNPs in the LMNA gene are known. They can manifest as changes in mRNA, splicing, or protein amino acid sequence (e.g. Arg471Cys, Arg482Gln, Arg527Leu, Arg527Cys, and Ala529Val). Progerin may also play a role in normal human aging, since its production is activated in typical senescent cells. Unlike other "accelerated aging diseases", such as Werner syndrome, Cockayne syndrome, or xeroderma pigmentosum, progeria may not be directly caused by defective DNA repair. These diseases each cause changes in a few specific aspects of aging but never in every aspect at once, so they are often called "segmental progerias". A 2003 report in Nature said that progeria may be a de novo dominant trait. It develops during cell division in a newly conceived zygote or in the gametes of one of the parents. It is caused by mutations in the LMNA (lamin A protein) gene on chromosome 1; the mutated form of lamin A is commonly known as progerin. One of the authors, Leslie Gordon, was a physician who did not know anything about progeria until her own son, Sam, was diagnosed at 22 months. Gordon and her husband, pediatrician Scott Berns, founded the Progeria Research Foundation.

The effects of drugs displacing each other and changing the clinical effect (though important in some examples) is vastly overestimated usually and a common example incorrectly used to display the importance of this effect is the anticoagulant warfarin. Warfarin is highly protein-bound (>95%) and has a low therapeutic index. Since a low therapeutic index indicates that there is a high risk of toxicity when using the drug, any potential increases in warfarin concentration could be very dangerous and lead to hemorrhage. In horses, it is very true that if warfarin and phenylbutazone are administered concurrently, the horse can develop bleeding issues which can be fatal. This is often explained as being due to the effect of phenylbutazone ejecting warfarin from its plasma protein, thus increasing the concentration of free warfarin and increasing its anticoagulant effect. However, the real problem is that phenylbutazone interferes with the liver's ability to metabolize warfarin so free warfarin cannot be metabolized properly or excreted. This leads to an increase in free warfarin and the resulting bleeding problems.

Sources: en.wikipedia.org

Background from the literature

The best-known brands labelled as cider are Golden Cap, Fizz, and Upcider. They typically contain 4.5–4.7% volume of alcohol. Virtually all Finnish "cider" is produced from fermented apple (or pear) juice concentrate mixed with water and is not cider as per the traditional description of the drink. Flavoured ciders, available in a large selection, are very popular and widely available in stores, with a variety of flavours ranging from forest berry to rhubarb and vanilla.

Impaired interoceptive sensitivity and interoceptive awareness can lead anorexia patients to adapt distorted interpretations of weight gain that are cued by physical sensations related to digestion (e.g. fullness). Combined, these interoceptive and emotional elements could together trigger maladaptive and negatively reinforced behavioral responses that assist in the maintenance of anorexia. In addition to metacognition, people with anorexia also have difficulty with social cognition including interpreting others' emotions, and demonstrating empathy. Abnormal interoceptive awareness and interoceptive sensitivity shown through all of these examples have been observed so frequently in anorexia that they have become key characteristics of the illness.

Senators Elizabeth Warren of Massachusetts and Bill Hagerty of Tennessee criticized regulators for protecting large depositors, including some of the venture capital firms that triggered the bank run. Republican lawmakers and financial policy experts criticized the emergency actions as a bailout that could create a moral hazard at other banks. Senator JD Vance of Ohio questioned whether the federal government would have taken similar action for a smaller bank or credit union. Economist Paul Krugman compared the failure and resulting government action to the savings and loan crisis. Economist Dean Baker contrasted the broad agreement behind rescuing relatively sophisticated Silicon Valley business proprietors with the objections over moral hazard and personal responsibility to President Biden's student loan forgiveness program. San Jose Chamber of Commerce CEO Derrick Seaver said any moral hazard was worth staving off the potential risk of allowing depositors to go unprotected. According to some experts, the government's quick reaction to the failure of Silicon Valley Bank, which had been viewed as having little significance outside of the technology sector until its failure, showed a fragile system addicted to injections of official support. Senator Warren, Representative Khanna, and Mayor Mahan called for earnings from CEO Greg Becker's recent sale of SVB shares to be clawed back and returned to depositors. Representative Eshoo criticized the last-minute bonuses given to bank employees as "highly offensive".

Due to the glans' high sensitivity, direct stimulation to it is not always pleasurable; instead, direct stimulation to the hood or near the glans is often more pleasurable, with the majority of women preferring to use the hood to stimulate the glans, or to have the glans rolled between the labia, for indirect touch. It is also common for women to enjoy the shaft being softly caressed in concert with the occasional circling of the glans. This might be with or without digital penetration of the vagina, while other women enjoy having the entire vulva caressed. As opposed to the use of dry fingers, stimulation from well-lubricated fingers, either by vaginal lubrication or a personal lubricant, is usually more pleasurable for the external clitoris. As the clitoris' external location does not allow for direct stimulation by penetration, any external clitoral stimulation while in the missionary position usually results from the pubic bone area. As such, some couples may engage in the woman-on-top position or the coital alignment technique, a sex position combining the "riding high" variation of the missionary position with pressure-counterpressure movements performed by each partner in rhythm with sexual penetration, to maximize clitoral stimulation. Same-sex female couples may engage in tribadism (vulva-to-vulva or vulva-to-body rubbing) for ample or mutual clitoral stimulation during whole-body contact. Pressing the penis in a gliding or circular motion against the clitoris or stimulating it by the movement against another body part may also be practiced.

The structure of a PAH influences whether and how the individual compound is carcinogenic. Some carcinogenic PAHs are genotoxic and induce mutations that initiate cancer; others are not genotoxic and instead affect cancer promotion or progression. PAHs that affect cancer initiation are typically first chemically modified by enzymes into metabolites that react with DNA, leading to mutations. When the DNA sequence is altered in genes that regulate cell replication, cancer can result. Mutagenic PAHs, such as benzo[a]pyrene, usually have four or more aromatic rings as well as a "bay region", a structural pocket that increases reactivity of the molecule to the metabolizing enzymes. Mutagenic metabolites of PAHs include diol epoxides, quinones, and radical PAH cations. These metabolites can bind to DNA at specific sites, forming bulky complexes called DNA adducts that can be stable or unstable. Stable adducts may lead to DNA replication errors, while unstable adducts react with the DNA strand, removing a purine base (either adenine or guanine). Such mutations, if they are not repaired, can transform genes encoding for normal cell signaling proteins into cancer-causing oncogenes. Quinones can also repeatedly generate reactive oxygen species that may independently damage DNA. Enzymes in the cytochrome family (CYP1A1, CYP1A2, CYP1B1) metabolize PAHs to diol epoxides. PAH exposure can increase production of the cytochrome enzymes, allowing the enzymes to convert PAHs into mutagenic diol epoxides at greater rates.

Sources: en.wikipedia.org

Frequently asked questions

What class of compound is PT-141?

It belongs to the melanocortin receptor agonist family of peptides. Its cyclic structure distinguishes it from linear peptides and shapes its receptor binding profile.

How was the compound originally identified?

It emerged from research on melanotan II. Investigators exploring derivatives observed distinct pharmacological features related to sexual function.

Which synonyms appear for PT-141?

Common names include bremelanotide and PT-141. Chemical databases may also list early development codes and descriptive names.

What does the code PT-141 designate?

PT-141 was the internal development code assigned to bremelanotide during preclinical research. Reference sources sometimes index the peptide under the code rather than the generic name. The two terms describe the same molecule.

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