They synthesized and tested several analogs, including peptides they subsequently named, melanotan-I and melanotan II.Very early in the process one of the scientists, Mac Hadley, who was conducting experiments on himself with the peptide melanotan II, injected himself with twice the dose he intended and experienced an eight-hour erection, along with nausea and vomiting.To pursue the tanning agent, melanotan-I was licensed by Competitive Technologies, a technology transfer company operating on behalf of University of Arizona, to an Australian startup called Epitan, which changed its name to Clinuvel in 2006.To pursue the sexual dysfunction agent, melanotan II was licensed by Competitive Technologies to Palatin Technologies. Palatin ceased development of melanotan-II in 2000, and synthesized, patented, and began to develop bremelanotide, a likely metabolite of melanotan-II that differs from melanotan-II in that it has a hydroxyl group where melanotan-II has an amide. Competitive Technologies sued Palatin for breach of contract and to try to claim ownership of bremelanotide; the parties settled in 2008, with Palatin retaining rights to bremelanotide, returning rights to melanotan-II to Competitive Technologies, and paying $800,000.In August 2004, Palatin signed an agreement with King Pharmaceuticals to co-develop bremelanotide in the US and jointly license it outside the US; King paid Palatin $20M upfront.Palatin conducted Phase II trials of intranasal bremelanotide in both female sexual dysfunction (FSD) and male erectile dysfunction (ED) but these trials were halted by the FDA in 2007, due to increased blood pressure in clinical trial subjects; Palatin stopped development of the intranasal formulation in 2008.
Contraindications
Due to its effects on blood pressure (generally a transient increase in systolic blood pressure by 6 mmHg, and diastolic blood pressure by 3 mmHg), bremelanotide is considered contraindicated in people with uncontrolled high blood pressure or cardiovascular disease. As long as bremelanotide is not used more than once in one day, it is not expected to cause more severe increases in blood pressure. Side effects
The most frequently encountered side effect of bremelanotide is nausea (40.0%), which may be intolerable to some people. The use of anti-nausea medications (e.g. ondansetron) prior to administration of bremelanotide may help to reduce the nausea. Other side effects may include flushing (20.3%), injection site reactions (13.2%), headache (11.3%), vomiting (4.8%), cough (3.3%), fatigue (3.2%), hot flushes (2.7%), paresthesia (2.6%), dizziness (2.2%), and nasal congestion (2.1%). Discoloration of the skin, specifically hyperpigmentation, may occur—especially if bremelanotide is used more than eight times in one month. The discoloration may not resolve upon stopping use of bremelanotide, and may occur on the face, gums, or breasts. Experiments in animals, even at high doses, failed to find any negative consequence of bremelanotide on fertility. Interactions
Bremelanotide does not meaningfully interact with alcohol, unlike flibanserin (for which the interaction with alcohol is a major barrier to its use). However, bremelanotide does interact with certain medications that people take by mouth. By slowing gastric motility, bremelanotide is thought to reduce the oral absorption (bioavailability) of certain medications, such as naltrexone and indomethacin.