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 2025-11-09 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H68N14O10 | Free base; the drug product is formulated as an acetate salt |
| Molar mass | About 1025 g/mol | Calculated for the free base |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| CAS Registry Number | 189691-06-3 | Common listing for the free base |
| Typical storage | -20 °C, desiccated, protected from light | Repeated freeze-thaw cycles are best avoided |
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.
Identity and purity are established with orthogonal methods rather than a single test. Reverse-phase high-performance liquid chromatography with ultraviolet detection gives a purity figure by area normalization, while mass spectrometry confirms the expected molecular ion. Amino acid analysis or peptide mapping can detect sequence errors that a mass value alone would miss, and residual counterion content is sometimes measured separately. Common impurities include truncated sequences, oxidized residues, and deamidated products; reporting them individually is more informative than a single composite purity number.
Lyophilized peptide arrives as a white to off-white cake or powder and is normally held at minus twenty degrees Celsius or colder for extended periods. Short-term bench work at ambient temperature is tolerable for minutes, not hours, because the solid is hygroscopic and picks up moisture that promotes hydrolysis. Vials should stay in a desiccator or a sealed bag with desiccant, protected from light, since aromatic residues in the sequence are susceptible to photo-oxidation. Inventory records that note arrival date and storage location reduce the chance of using degraded material.
The New York term hero is first attested in 1937. The name is sometimes credited to the New York Herald Tribune food writer Clementine Paddleford in the 1930s, but there is no good evidence for the claim. It is also sometimes said that it is related to the gyro; that is unlikely as the gyro was unknown in the United States until the 1960s. Hero (plural usually heros not heroes) remains the prevailing New York City term for most sandwiches on an oblong roll with a generally Italian flavor, in addition to the original described above. Pizzeria menus often include eggplant parmigiana, chicken parmigiana, and meatball heros, each served with sauce.
The flowers are small, produced on pendulous spikes 4 to 8 cm (1+1⁄2 to 3 in) long at the leaf nodes, the spikes lengthening up to 7 to 15 cm (2+3⁄4 to 6 in) as the fruit matures. A single stem bears 20 to 30 fruiting spikes. The fruit of the black pepper is a drupe and when dried is known as a peppercorn.Within the genus Piper, black pepper is most closely related to other Asian species such as P. caninum.
The jury acquitted Letby of the attempted murder on counts 9 (Baby G) and 10 (Baby H), and was unable to reach verdicts on counts 11 (Baby H), 13 (Baby J), 14, (Baby K), 18 and 19 (Baby N), and 22 (Baby Q). On 21 August 2023, Letby was sentenced to life imprisonment with a whole life order, the most severe penalty available under English law. She became the fourth woman in the UK to receive such a sentence. In his remarks, Goss described her actions as "a cruel, calculated and cynical campaign of child murder involving the smallest and most vulnerable of children", adding that "there was a deep malevolence bordering on sadism [...] you [Letby] have no remorse [...] there are no mitigating factors [...] the offences are of sufficient severity to require a whole life order." Letby chose not to attend the sentencing hearing and therefore did not hear the victim impact statements or the sentence being passed. In response, the Secretary of State for Justice, Alex Chalk, said the government would "look at options to change the law at the earliest opportunity" to require defendants to attend their sentencing. Following the trial, Letby was transferred to HMP Low Newton in County Durham. As of February 2025, she is held at HM Prison Bronzefield.
==== Silver ==== Silver ions have been shown to react with the thiol group in enzymes and inactivate them, leading to cell death. These ions can inhibit oxidative enzymes such as yeast alcohol dehydrogenase. Silver ions have also been shown to interact with DNA to enhance pyrimidine dimerization by the photodynamic reaction and possibly prevent DNA replication. The use of silver as an antimicrobial is well documented.
Sources: en.wikipedia.org
Some brewers add one or more clarifying agents to beer, which typically precipitate (collect as a solid) out of the beer along with protein solids and are found only in trace amounts in the finished product. This process makes the beer appear bright and clean, rather than the cloudy appearance of ethnic and older styles of beer such as wheat beers. Examples of clarifying agents include isinglass, obtained from swim bladders of fish; Irish moss, a seaweed; kappa carrageenan, from the seaweed kappaphycus; polyclar (a commercial brand of clarifier); and gelatin. If a beer is marked "suitable for Vegans", it was generally clarified either with seaweed or with artificial agents, although the "Fast Cask" method invented by Marston's in 2009 may provide another method.
Zidesamtinib, sold under the brand name Jideytro, is an anti-cancer medication used for the treatment of non-small cell lung cancer. Zidesamtinib is a kinase inhibitor. It is taken by mouth. Zidesamtinib was approved for medical use in the United States in July 2026.
Aluminum sulfide is a chemical compound with the formula Al2S3. This colorless species has an interesting structural chemistry, existing in several forms. The material is sensitive to moisture, hydrolyzing to hydrated aluminum oxides/hydroxides. This can begin when the sulfide is exposed to the atmosphere. The hydrolysis reaction generates gaseous hydrogen sulfide (H2S).
The peer-reviewed journal facilitated discourse around regenerative medicine by publishing innovative research on stem cell therapies, gene therapies, tissue engineering, and biomechanical prosthetics. The Society for Regenerative Medicine, later renamed the Regenerative Medicine and Stem Cell Biology Society, served a similar purpose, creating a community of like-minded experts from around the world. In June 2008, at the Hospital Clínic de Barcelona, Professor Paolo Macchiarini and his team, of the University of Barcelona, performed the first tissue engineered trachea (wind pipe) transplantation. Adult stem cells were extracted from the patient's bone marrow, grown into a large population, and matured into cartilage cells, or chondrocytes, using an adaptive method originally devised for treating osteoarthritis. The team then seeded the newly grown chondrocytes, as well as epithelial cells, into a decellularised (free of donor cells) tracheal segment that was donated from a 51-year-old transplant donor who had died of cerebral hemorrhage. After four days of seeding, the graft was used to replace the patient's left main bronchus. After one month, a biopsy elicited local bleeding, indicating that the blood vessels had already grown back successfully. In 2009, the SENS Foundation was launched, with its stated aim as "the application of regenerative medicine – defined to include the repair of living cells and extracellular material in situ – to the diseases and disabilities of ageing".
, a common prediction of many GUT models. This channel has a very clean signature, with no invisible particles in the final state. This allows for full reconstruction of the proton mass from the decay products, and, since it is a two-body decay, the total recoil momentum is expected to be small. Supersymmetric extensions of GUT models favor the
Sources: en.wikipedia.org
Estradiol is available as a transdermal gel in the form of gel dispensers and gel packets. Major estradiol gel dispenser products include EstroGel and Elestrin while major estradiol gel packet products include DiviGel and Sandrena. Estradiol gels are administered daily. When estradiol is administered as a hydroalcoholic gel, it dries within 2 to 5 minutes following application to the skin. A single application of a transdermal estradiol gel results in a sustained increase in estradiol levels for at least 24 hours. The apparent elimination half-life of estradiol with transdermal estradiol gel is 36 hours. Once daily application of 1.25 g topical gel containing 0.75 mg estradiol (brand name EstroGel) for 2 weeks was found to produce mean peak estradiol and estrone levels of 46.4 pg/mL and 64.2 pg/mL, respectively. The time-averaged levels of circulating estradiol and estrone with this formulation over the 24-hour dose interval were 28.3 pg/mL and 48.6 pg/mL, respectively. Levels of estradiol and estrone are stable and change relatively little over the course of the 24 hours following an application, indicating a long duration of action of this route. Steady-state levels of estradiol are achieved after 3 days of application. A higher dosage of estradiol gel containing 1.5 mg estradiol per daily application has been found to produce mean estradiol levels of 40 to 100 pg/mL and estrone levels of 90 pg/mL, while 3 mg per day has been found to result in respective mean estradiol and estrone levels of 60 to 140 pg/mL and 45 to 155 pg/mL.
=== Amino acids === Arthropod hemolymph contains high levels of free amino acids. Most amino acids are present but their relative concentrations vary from species to species. Concentrations of amino acids also vary according to the arthropod stage of development. An example of this is the silkworm and its need for glycine in the production of silk.
[HbH]+ + O2 ⇌ HbO2 + H+ as this shows that when hydrogen ion concentration increases the equilibrium is shifted to the left in accordance with Le Châtelier's principle. Hydrogen ion concentration can be increased by the presence of carbon dioxide, which behaves as a weak acid.
=== Industrial synthesis === Vitamin D3 (cholecalciferol) is produced industrially by exposing 7-dehydrocholesterol to UVB and UVC light, followed by purification. The 7-dehydrocholesterol is sourced as an extraction from lanolin, a waxy skin secretion in sheep's wool. Vitamin D2 (ergocalciferol) is produced in a similar way using ergosterol from yeast as a starting material.
The ONDCP stated in April 2011 that there had been a 46% drop in cocaine use among young adults over the previous five years, and a 65% drop in the rate of people testing positive for cocaine in the workplace since 2006. At the same time, a 2007 study found that up to 35% of college undergraduates used stimulants not prescribed to them. A 2013 study found that prices of heroin, cocaine and cannabis had decreased from 1990 to 2007, while the purity of these drugs had increased. The National Survey on Drug Use and Health for 2019 found that 1.7% of US adults over 25 had used cocaine in the previous 12 months, compared to 1.8% in 2002, and cannabis use went from 7% in 2002 to 15.2%. The DEA's 2021 National Drug Threat Assessment stated that "a steady supply of cocaine was available throughout domestic markets" in 2019 and 2020. According to the Centers for Disease Control (CDC), drug abuse fatalities in 2021 reached an all-time high of 108,000 deaths, a 15% increase from 2020 (93,000) which, at the time, was the highest number of deaths and a 30% increase from 2019. During alcohol prohibition, from 1920 to 1933, alcohol use initially fell but began to increase as early as 1922. It has been extrapolated that even if prohibition had not been repealed in 1933, alcohol consumption would have surpassed pre-prohibition levels. One argument against the war on drugs is that it uses similar measures as Prohibition and is no more effective.
Sources: en.wikipedia.org
PT-141 is a research code for bremelanotide, a cyclic peptide that activates melanocortin receptors. It was developed for sexual dysfunction and later approved under a brand name as a subcutaneous injection. The same code is widely used by suppliers selling non-pharmaceutical material.
Both are synthetic melanocortin agonists and share a similar peptide backbone, but they are distinct molecules with different receptor profiles. Melanotan II was never approved as a medicine, whereas bremelanotide was. Findings about one compound should not be transferred to the other without direct evidence.
It is typically distributed as a lyophilized powder in sealed vials, sometimes with a separate solvent. Purity statements usually originate from the supplier rather than an independent laboratory. Storage recommendations vary between vendors, which makes comparison across sources difficult.
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.