Research Paper Reviews
The 1998 ipamorelin paper showed selectivity in animals. It did not finish a medicine.
Raun and colleagues described a pentapeptide that released growth hormone in rats and swine with less effect on ACTH and cortisol. The last line of the abstract is a hope, not an approval.
The paper people cite for ipamorelin is Raun and colleagues, European Journal of Endocrinology, 1998. It is a pharmacology paper. In rat pituitary cells the authors report growth-hormone release with a potency they compare with an older peptide, GHRP-6. In anaesthetised rats and in conscious swine they report growth-hormone release in vivo. They also report that ACTH and cortisol did not rise the way they did with less selective secretagogues, including at doses well above the growth-hormone dose in those models.
What the abstract promises
The closing sentence calls ipamorelin a candidate for future clinical development. Candidate is the whole claim. The experiments are cells, rats, and swine. A selective animal pharmacology result is not a human efficacy trial, not a dosing table, and not evidence that a later catalog vial matches the batch Novo Nordisk described in 1998.
How to read the concentration
An EC50 in nanomoles per litre, measured in a dish of rat pituitary cells, is not a milligram dose for a person. This review leaves the concentration in the assay where the authors put it. The PMID is 9849822.