This is a working overview of cyclic heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-02. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
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.
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.
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.
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.
Published discussion sits at the intersection of peptide chemistry, neuroendocrinology and sexual medicine. Trial reports emphasise change scores on validated instruments, while mechanistic papers focus on hypothalamic circuits and receptor selectivity. Because placebo response in this field is large, effect sizes are usually reported with confidence intervals rather than as isolated averages. Reviews note that female and male data sets are not interchangeable and should be read separately. Diagnostic terminology has been revised over time, which complicates comparison between older and newer studies.
Bremelanotide is a synthetic cyclic heptapeptide that acts on a family of G-protein-coupled receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide associated with pigmentation and several central signalling pathways. A lactam bridge constrains the ring and slows enzymatic breakdown, which distinguishes it from the linear parent molecule. Research interest moved over time from pigment biology toward central nervous system effects, particularly circuits connected to sexual desire. Parenteral delivery is used because oral bioavailability is poor.
Theodor W. Adorno (; German: [ˈteːodoːɐ̯ aˈdɔʁno] ; born Theodor Ludwig Wiesengrund; 11 September 1903 – 6 August 1969) was a German philosopher, cultural, and music critic. He was a leading member of the Frankfurt School of critical theory, whose work has come to be associated with thinkers such as Ernst Bloch, Walter Benjamin, Max Horkheimer, Erich Fromm, and Herbert Marcuse, for whom the works of Sigmund Freud, Karl Marx, and G. W. F. Hegel were essential to a critique of modern society. As a critic of both fascism and what he called the culture industry, he authored numerous works—such as Dialectic of Enlightenment (1947), Minima Moralia (1951), and Negative Dialectics (1966)—that strongly influenced the European New Left. In an intellectual climate shaped by existentialism and logical positivism, Adorno developed a dialectical conception of history and philosophy that challenged the foundations of both, anticipating the divide that would later emerge between the analytic and continental traditions. As a classically trained musician, Adorno studied composition with Alban Berg of the Second Viennese School, influenced by his early admiration for the music of Arnold Schoenberg. Adorno's commitment to avant-garde music formed the backdrop of his subsequent writings and led to his collaboration with Thomas Mann on the latter's novel Doctor Faustus (1947), while the two men lived in California as exiles during the Second World War.
=== Sources === Ammirati JF, Traquair JA, Horgen PA (1985). Poisonous Mushrooms of Canada: Including other Inedible Fungi. Markham, Ontario: Fitzhenry & Whiteside in cooperation with Agriculture Canada and the Canadian Government Publishing Centre, Supply and Services Canada. ISBN 978-0-88902-977-4. Hall IR, Stephenson SL, Buchanan PK, Yun W, Cole AL (2003). Edible and Poisonous Mushrooms of the World. Portland, Oregon: Timber Press. ISBN 978-0-88192-586-9. Stuntz DE, Largent DL, Thiers HD, Johnson DJ, Watling R (1978). How to Identify Mushrooms to Genus I. Eureka, California: Mad River Press. ISBN 978-0-916422-00-4. Jaini, Padmanabh S. (1998) [1979], The Jain Path of Purification, Delhi: Motilal Banarsidass, ISBN 978-81-208-1578-0 Laidlaw, James (1995), Riches and Renunciation. Religion, economy, and society among the Jains, Oxford, ISBN 978-0198280316
=== Ultrasound === Obstetric ultrasonography may also be used to detect and diagnose pregnancy. It is very common to have a positive at-home urine pregnancy test before an ultrasound. Both abdominal and vaginal ultrasound may be used, but vaginal ultrasound allows for earlier visualization of the pregnancy. With obstetric ultrasonography the gestational sac (intrauterine fluid collection) can be visualized at 4.5 to 5 weeks gestation, the yolk sac at 5 to 6 weeks gestation, and fetal pole at 5.5 to 6 weeks gestation. Ultrasound is used to diagnose multiple gestation, which cannot be diagnosed based on the presence of hCG in urine or blood. Determination of the gestational age of the embryo/fetus is an additional benefit of ultrasound compared to hCG tests.
== Gymnastics scandals == Age controversies in gymnastics USA Gymnastics sex abuse scandal – former USA Gymnastics national team doctor, Larry Nassar, was accused of sexual abuse by more than 150 girls and women. Nassar was sentenced to 60 years in prison on federal child pornography charges in December 2017, and was sentenced to 80 to 300 years in prison after two separate trials on sexual assault charges in January 2018, to be served consecutively.
Sources: en.wikipedia.org
== Further reading == Arms, Thomas S. Encyclopedia of the Cold War (1994). Brune, Lester H. Chronology of the Cold War, 1917–1992 (Routledge, 2006) 720 pp of brief facts Hanes, Sharon M. and Richard C. Hanes. Cold War Almanac (2 vol 2003), 1460pp of brief facts Parrish, Thomas. The Cold War Encyclopedia (1996) Trahair, Richard C.S. and Robert Miller. Encyclopedia of Cold War Espionage, Spies, and Secret Operations (2012). excerpt Tucker, Spencer C. and Priscilla Mary Roberts, eds. The Encyclopedia of the Cold War: A Political, Social, and Military History (5 Vol., 2007). excerpt van Dijk, Ruud, ed. Encyclopedia of the Cold War (2 vol. 2017) excerpt
The German oculist Burchard Mauchart provided an early description in a 1748 doctoral dissertation of a case of keratoconus, which he called staphyloma diaphanum. However, it was not until 1854 that British physician John Nottingham (1801–1856) clearly described keratoconus and distinguished it from other ectasias of the cornea. Nottingham reported the cases of "conical cornea" that had come to his attention, and described several classic features of the disease, including polyopia, weakness of the cornea, and difficulty matching corrective lenses to the patient's vision. In 1859, British surgeon William Bowman used an ophthalmoscope (recently invented by Hermann von Helmholtz) to diagnose keratoconus, and described how to angle the instrument's mirror so as to best see the conical shape of the cornea. Bowman also attempted to restore vision by pulling on the iris with a fine hook inserted through the cornea and stretching the pupil into a vertical slit, like that of a cat. He reported that he had had a measure of success with the technique, restoring vision to an 18-year-old woman who had previously been unable to count fingers at a distance of 8 inches (20 cm). By 1869, when the pioneering Swiss ophthalmologist Johann Horner wrote a thesis entitled On the treatment of keratoconus, the disorder had acquired its current name.
Insulin icodec, sold under the brand name Awiqli, is an ultralong-acting basal insulin analogue used in the treatment of diabetes. It is administered by subcutaneous injection once weekly. It was developed by Novo Nordisk. Insulin icodec was designed to provide basal insulin coverage with once-weekly dosing. It is approved for medical use in Canada, the European Union, Australia, and in the United States.
Sources: en.wikipedia.org
Oliver Platt (born January 12, 1960) is an American actor known for his work on stage and screen. He has been nominated for five Primetime Emmys, a Golden Globe Award, two Screen Actors Guild Awards, and one Tony Award. Following his acting debut in the 1988 film Married to the Mob, Platt gained prominence for his roles in Working Girl (1988), Flatliners (1990), Beethoven (1992), Indecent Proposal, Benny & Joon, The Three Musketeers (all 1993), A Time to Kill (1996), The Impostors, Bulworth, Dr. Dolittle (all 1998), Lake Placid, Three to Tango, and Bicentennial Man (all 1999). His other notable credits include Gun Shy, Ready to Rumble (both 2000), Don't Say a Word (2001), Pieces of April (2003), Kinsey (2004), The Ice Harvest, Casanova (both 2005), Frost/Nixon (2008), Year One, 2012 (both 2009), Please Give, Love & Other Drugs (both 2010), and X-Men: First Class (2011). Platt is known for his work on television series such as The Big C (2010–2013), Fargo (2014) and The Good Wife (2015). He received a Screen Actors Guild Award nomination for his portrayal of George Steinbrenner in the ESPN miniseries The Bronx Is Burning (2007) as well as nominations for the Primetime Emmy for Outstanding Guest Actor for his roles in The West Wing (2001), Huff (2005; 2006), and Nip/Tuck (2008). He is known for his recurring role as Uncle Jimmy on Hulu's The Bear (2022–2026) and has played Dr. Daniel Charles on Chicago Med since 2015. On stage, Platt made his Broadway debut in the Conor McPherson play Shining City (2006) for which he was nominated for the Tony Award for Best Actor.
He explains that he could not pass up the opportunity to marry a royal princess, as Medea is only a barbarian woman, but hopes to someday join the two families and keep Medea as his mistress. Medea, and the chorus of Corinthian women, do not believe him. She reminds him that she left her own people for him ("I rescued you [...] I betrayed both my father and my house [...] now where should I go?"), and that she saved him and slew the dragon. Jason promises to support her after his new marriage ("If you wish me to give you or the children extra money for your trip into exile, tell me; I'm ready to give it with a lavish hand"), but Medea spurns him: "Go on, play the bridegroom! Perhaps [...] you've made a match you'll one day have cause to lament." In the following scene Medea encounters Aegeus, king of Athens. He reveals to her that despite his marriage he is still without children. He visited the oracle who merely told him that he was instructed "not to unstop the wineskin's neck". Medea relays her current situation to him and begs for Aegeus to let her stay in Athens if she gives him drugs to end his infertility. Aegeus, unaware of Medea's plans for revenge, agrees. Medea then returns to plotting the murders of Glauce and Creon. She decides to poison some golden robes (a family heirloom and gift from the sun god Helios, her grandfather) and a coronet, in hopes that the bride will not be able to resist wearing them, and consequently be poisoned.
Fialuridine (FIAU) is a synthetic, solid, fluorinated nucleoside analogue of thymidine that was investigated as a treatment for chronic hepatitis B virus infection (HBV) in the early 1990s. Its effectiveness was evaluated during a Phase II clinical trial over a six-month course, with 24 patients treated. FIAU was provided by Oclassen Pharmaceuticals and administered under an Investigational New Drug Application held by Eli Lilly and Company. Administration of FIAU resulted in antiviral activity, alongside several side effects which resulted in the termination of some clinical trials. Investigations found that affected patients suffered a depletion of mitochondrial DNA (mtDNA) in both liver and muscle tissue, establishing mitochondrial dysfunction as a contributing mechanism to toxicity. The FIAU trial is considered a landmark case in drug production and influenced subsequent drug safety assessments regarding mitochondrial toxicity.
The Department was founded in 1934 in Kazan Teachers’ Institute to educate future teachers of chemistry. In November, 2011 the Department of Chemical Education became a structural unit of A. M. Butlerov Institute of Chemistry of Kazan (Volga Region) Federal University. Educational research was combined with fundamental and applied research in chemistry. International, All-Russian and regional research-to-practice conferences on chemical education organized by the Department are of the utmost interest. The Department has received letters of gratitude from school principals for instructing students in research and methodology in their preparation for teaching practice. Today 3 Doctors of Science and 5 Doctors of Philosophy are involved in the educational and bringing-up process at the Department. Since 2010 teachers have been retrained in the field of “Teacher of Chemistry”.The head of the Department is Suria I. Gilmanshina, Doctor of Philosophy in Chemistry, Doctor of Science in Education. The Department conducts research in the following fields:
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 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.