Pharmacology
Pharmacology: 7 articles from Peptides Facts. Evidence-led reference on research peptides.
Afamelanotide: MC1R Agonism and Two Phase 3 Trials
Two amino acid substitutions turn alpha-MSH into a licensed medicine for one rare photodermatosis. The receptor mechanism is straightforward; the two pivotal trials produced numbers an order of magnitude apart.
Setmelanotide: MC4R Agonism in Monogenic Obesity
A melanocortin-4 receptor agonist licensed for a handful of named genetic conditions. The pharmacology explains why the indication is that narrow, and the trial designs explain how ten participants were enough.
Peptide Half-Life: Why Clearance Is So Fast, and the Five Ways It Is Slowed
Two independent systems remove peptides from circulation — peptidases cut them and the kidney filters them — and both work quickly. Extending half-life means defeating both, and every method of doing so has a price.
PT-141 (Bremelanotide): Melanocortin Pharmacology and the Development Story
A metabolite of Melanotan II that took the other road: randomised trials, a formulation abandoned over a blood pressure signal, and an approval. The mechanism is central, and the effect size is modest.
Retatrutide: Triple Glucagon, GIP and GLP-1 Receptor Agonism, and the Balance It Has to Strike
Retatrutide adds a glucagon receptor arm to the two incretin receptors tirzepatide already engages. Glucagon raises blood glucose, which makes that the most counterintuitive design decision in the class — and the reason the molecule acts on energy expenditure as well as intake.
CJC-1295, the Drug Affinity Complex, and the Half-Life That Defines It
CJC-1295 with DAC and "CJC-1295 without DAC" are not two versions of one compound. They are different molecules whose half-lives differ by orders of magnitude, and only one of them is what the published literature calls CJC-1295.
Tirzepatide: Dual GIP and GLP-1 Receptor Agonism, and Why the Balance Is Uneven
Tirzepatide engages two incretin receptors instead of one, and it does not engage them equally. The receptor-level asymmetry is the most interesting thing about the molecule, and the part of it that is least settled.