The short version of bremelanotide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-05. Anything still debated is marked as such rather than presented as settled.
Bremelanotide is a synthetic cyclic heptapeptide developed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation and appetite signalling. Its structure contains seven amino acid residues joined by a lactam bridge that closes the ring between two side chains. The molecular formula is C50H68N14O10 and the nominal molecular mass is near 1025 daltons. Much of the early laboratory literature refers to the same molecule by the development code PT-141.
The compound emerged from a research programme examining melanocortin analogues for effects on skin pigmentation. During early human studies, participants reported spontaneous erections as an unexpected side effect, which redirected development toward sexual function rather than tanning. An intranasal formulation was investigated in clinical trials but did not reach market approval. A subcutaneous injectable version later completed the regulatory process, and the nasal route does not appear in approved labelling.
Approved use is narrow and jurisdiction-specific. In the United States, the injectable product is authorised for premenopausal women with acquired, generalised hypoactive sexual desire disorder, a diagnosis that requires documented distress. It is not approved for men, for postmenopausal women, or for use alongside hormonal contraceptives under the approved labelling. Outside regulated markets, the same peptide is frequently sold as a research chemical, where identity, purity, and sterility are not independently verified.
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 |
|---|---|---|
| Molecular formula | C50H68N14O10 | Cyclic heptapeptide backbone |
| Molecular mass | Approximately 1025 Da | Nominal mass of the free peptide |
| Appearance | White to off-white lyophilised powder | Typical for purified synthetic peptides |
| Solubility class | Freely soluble in water | Organic solubility is limited |
| Typical storage temperature | −20 °C or below | Protect from moisture and light |
Lyophilised peptide is generally held below minus twenty degrees Celsius, protected from light and moisture, because hydrolysis and oxidation accumulate faster at ambient temperature. Once reconstituted, solutions are typically kept between two and eight degrees Celsius and used within a short window defined by the supplier. Repeated freeze-thaw cycles are avoided since they promote aggregation and loss of soluble material. Container material matters as well, because peptides adsorb to certain plastics and glass surfaces at low concentration. Stability figures supplied by a vendor apply only to the specific lot and buffer that were tested.
Identity and purity are usually established with reversed-phase high-performance liquid chromatography combined with mass spectrometry. A gradient of water and acetonitrile containing trifluoroacetic acid is a common mobile phase, and ultraviolet detection near 214 nanometres responds to the peptide backbone. Mass spectrometry confirms the expected molecular mass and helps reveal truncation or oxidation products. Purity is reported as a peak-area percentage, a figure that depends on the wavelength and gradient used, so values from different laboratories are not always directly comparable. Peptide mapping and amino acid analysis provide additional confirmation when required.
Regulatory status varies by jurisdiction, where approved prescription products, compounded preparations and research-grade material are treated as distinct categories with different documentation requirements. Suppliers of research material commonly issue a certificate of analysis listing purity, identity and sometimes endotoxin content. Independent verification by a third-party laboratory is often recommended because self-reported figures are difficult to check. Literature discussions usually state the source, purity and storage conditions of the material used, since these details affect reproducibility. Analysts note that a reported purity figure does not by itself describe biological activity.
Reverse-phase high-performance liquid chromatography is the standard method for assessing purity. Mass spectrometry confirms molecular identity and detects sequence variants or truncation products. Ultraviolet absorbance at 214 or 280 nm is used for quantification, with the choice depending on the peptide sequence. Method validation typically addresses linearity, limit of detection, and precision across a defined concentration range. Impurity profiling may also employ ion-exchange or size-exclusion chromatography, and these techniques complement one another.
Certificate of analysis documents usually report purity percentage, molecular weight, and appearance. Researchers verify identity by comparing observed and theoretical mass values. Chain-of-custody records and batch numbers help trace material from source to experiment. Independent verification of supplier claims is considered good practice when material identity is critical to a study. Records should include the storage history of each aliquot, and unexpected deviations in appearance or solubility warrant re-testing before use.
Lyophilized peptide material is generally stored at -20 °C or below to limit degradation, while reconstituted solutions are less stable and are typically kept refrigerated and protected from light. Repeated freeze-thaw cycles can accelerate aggregation and should be minimized. Stability for any specific lot depends on purity, moisture content, and packaging. Handling in a temperature-controlled environment reduces variability across replicates, and exposure to ambient humidity during weighing can introduce error. Aliquotting reduces the number of times a stock container is opened.
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.
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.
=== An overview of the GW model === Greenwood and Williamson in 1966 (GW) proposed a theory of elastic contact mechanics of rough surfaces which is today the foundation of many theories in tribology (friction, adhesion, thermal and electrical conductance, wear, etc.). They considered the contact between a smooth rigid plane and a nominally flat deformable rough surface covered with round tip asperities of the same radius R. Their theory assumes that the deformation of each asperity is independent of that of its neighbours and is described by the Hertz model. The heights of asperities have a random distribution. The probability that asperity height is between
==== Quantities required ==== A rule of thumb for dry ice bath branding states that twenty pounds (9.1 kg) of dry ice and three US gallons (11 L) of 99% alcohol are sufficient to freeze-brand one hundred head of cattle inside a three to four-hour period. An entire day of freeze branding may consume 50–75 pounds (23–34 kilograms) of dry ice and six to nine US gallons (23 to 34 L) of ethanol. The dry ice should be broken up into egg-sized pieces, placed in a styrofoam container or styrofoam-insulated metal cooler and covered with at least three inches (7.6 cm) of alcohol. Many consumer coolers are made from plastics that become exceptionally brittle at cryogenic temperatures. This is a safety concern if heavy metal brands are frequently returned to coolant baths because 99% alcohol is extremely flammable. Insulated aluminum containers are preferred.
=== Infertility === It can be difficult to become pregnant with PMOS due to irregular ovulation. The first management step is to improve the general health of the mother, such as through lifestyle interventions. GLP-1 agonist for weight loss can be used, but should be stopped at least 2 months before conception. As of 2025, there is not enough data to know if they are safe in pregnancy. Pregnancy in PMOS is more risky than normal, and treatment is focused on getting a single pregnancy, rather than, for instance, twins (multiple pregnancy). With treatment, the eventual family size of women with PMOS does not seem different to those without. The first-line medical treatment for infertility in women with PMOS is letrozole (Femara) to induce ovulation. This is, in general, more effective than clomiphene citrate to improve both pregnancy rates and live births. Other medications that can be used to treat infertility, listed from most to least effective, are metformin + clomiphene citrate, clomiphene citrate alone, and metformin alone. Women may be more likely to experience gastrointestinal side effects with metformin. Gonadotrophin therapy may be effective too, but requires monitoring and increases the risks of multiple pregnancies. When medication and lifestyle interventions are ineffective, infertility can be treated with a laparoscopic procedure called "ovarian drilling", which involves puncture of 4–10 small follicles with electrocautery, laser, or biopsy needles.
Ossuaries were used for interring human skeletal remains by Second Temple Jews and early Christians. Promession is a method of freeze drying human remains before burial to increase the rate of decomposition. Resomation accelerates disposal through the process of alkaline hydrolysis. Sky burial places the body on a mountaintop, where it decomposes in the elements or is scavenged by carrion eaters, particularly vultures.
Sources: en.wikipedia.org
== External links == GeneReviews/NCBI/NIH/UW entry on Pseudoachondroplasia GeneReviews/NCBI/NIH/UW entry on Multiple Epiphyseal Dysplasia, Dominant cartilage+matrix+protein at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
There are 12 non-working public holidays, including the Great Union Day, celebrated on 1 December in commemoration of the 1918 union of Transylvania with Romania. Winter holidays include the Christmas and New Year festivities during which various unique folklore dances and games are common: plugușorul, sorcova, ursul, and capra. The traditional Romanian traditional clothing that otherwise has largely fallen out of use during the 20th century, is a popular ceremonial vestment worn on these festivities, especially in rural areas. There are sacrifices of live pigs during Christmas and lambs during Easter that has required a special exemption from EU law after 2007. In the Easter, traditions such as painting the eggs are very common. On 1 March mărțișor gifting is featured, which is a tradition whereby females are gifted with a type of talisman that is given for good luck.
== Variants == Chocolate agar with the addition of bacitracin becomes selective for the genus Haemophilus. Another variant of chocolate agar called Thayer–Martin agar contains an assortment of antibiotics that select for Neisseria species.
Sources: en.wikipedia.org
genotoxicity The ability of certain chemical agents to cause damage to genetic material within a living cell (e.g. through single- or double-stranded breaks, crosslinking, or point mutations), which may or may not result in a permanent mutation. Though all mutagens are genotoxic, not all genotoxic compounds are mutagenic.
At the same time, Kissinger met with Dobrynin to warn him that Nixon was a dangerous man who wanted to escalate the Vietnam war. In April 1969, North Korea shot down a U.S. Navy plane on a spy mission, killing 31 airmen. Kissinger wanted to bomb a North Korean air base in retaliation, being opposed by the Defense Secretary Melvin Laird, the Secretary of State William Rogers and General Earle Wheeler, the chairman of the joint chiefs of staff, who all warned that to bomb North Korea might start a second war in Asia. Kissinger argued that bombing North Korea would help end the Vietnam war, saying: "Hanoi might say, 'This guy [Nixon] is becoming irrational'-and we'd better settle with him". Unable to gain support at the National Security Council, Kissinger appealed to Nixon's Domestic Affairs Adviser, John Ehrlichman, saying that, though striking in North Korea might cause a second Korean war, it might also help with the Vietnam war. When Ehrlichman asked Kissinger how far things might escalate if the U.S. bombed North Korea, he was told: "Well, it could go nuclear". Ehrlichman came away convinced that Kissinger with his thick German accent, academic titles, advocacy of a ruthless foreign policy and a role as a senior presidential adviser seemed too much like the eponymous character of the 1964 black comedy Dr. Strangelove and advised Nixon not to strike North Korea, advice that was accepted. Starting in April 1969, Kissinger pressed for a plan code-named Operation Duck Hook, which would see the United States return to bombing North Vietnam and possibly use nuclear weapons.
Foot ulcers in diabetes require a multidisciplinary team that may include the primary care doctor, a diabetes nurse specialist, a tissue viability nurse, podiatrists, vascular surgeons, diabetes specialists and surgeons. An aim to improve glycemic control, if poor, may slow disease progression. When osteomyelitis is suspected to be involved in the foot, but not evidenced on an x-ray, an MRI scan should be obtained. In those with a high likelihood of osteomyelitis, a combination of x-ray and being able to probe to bone can reliably diagnose osteomyelitis without the need for more advanced imaging. A bone biopsy with culture is the gold standard for diagnosing osteomyelitis. With regards to infected foot ulcers, the presence of microorganisms is not in itself enough to determine whether an infection is present. Signs of an infection, such as erythema, purulence, fluctuance, swelling, warmth, or discharge, should also be present. The most common organism causing infection is staphylococcus. The treatment consists of debridement, appropriate bandages, managing peripheral arterial disease and appropriate use of antibiotics (against pseudomonas aeruginosa, staphylococcus, streptococcus and anaerobe strains), and arterial revascularization if necessary.
=== Progestogenic activity === CPA is a highly potent progestogen. It is described as the most potent progestin of the 17α-hydroxyprogesterone group, being about 1,200-fold more potent than hydroxyprogesterone acetate, 12-fold more potent than medroxyprogesterone acetate, and 3-fold more potent than chlormadinone acetate in animal bioassays. Based on results in the animal bioassays, CPA has also been said to be the most potent progestin known, with 1,000 times the potency of progesterone. With oral administration in humans however, CPA is distinctly less potent as a progestogen than various other progestins such as the 19-nortestosterone derivatives. The effective dosage of CPA needed to inhibit ovulation by itself in women (i.e., to act as a contraceptive) is 1 mg/day, and the medication is marketed as a contraceptive (combined with low-dose ethinylestradiol) at a dosage of 2 mg/day. For comparison, the ovulation-inhibiting dosage of levonorgestrel is 50 μg/day. At the dosages typically used clinically, CPA is described as a "strong" and "powerful" progestogen. Its endometrial transformation dosage is 20 to 30 mg per cycle and its menstrual delay test dosage has been estimated to be less than 1 mg/day. CPA is not well-balanced in terms of its activities; relative to the progestogenic potency of CPA, its potency as an androgen receptor antagonist is quite weak. In order to take full advantage of its antiandrogenic activity, CPA must be administered at a dosage of 50 to 100 mg per day, which is 2 to 3 times the cyclical endometrial transformation dose per day.
Sources: en.wikipedia.org
It is a synthetic cyclic peptide that acts as an agonist at melanocortin receptors. It is not a hormone replacement therapy and not a vasodilator in the usual clinical sense, although it does affect vascular tone. Chemically it belongs to the melanocortin analogue family.
PT-141 was the internal development code used during early research and it persists in older publications, conference abstracts, and informal listings. The code and the approved name refer to the same molecule. Its continued use reflects habit in the literature rather than any difference in substance.
No. The intranasal form was studied in trials but was never approved, and absorption through the nasal route varies considerably between individuals. Approved labelling covers a subcutaneous injection only. Any nasal product sold outside regulated channels falls outside verified manufacturing.
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.