Ipamorelin is the synthetic pentapeptide Aib-His-D-2-Nal-D-Phe-Lys-NH2. Almost everything about it is built for resistance: an unnatural residue at the front, two D-amino acids in the middle, an amidated C-terminus, and none of the residues behind the usual oxidation and deamidation routes. It is also strongly basic, so it dissolves in water readily.
This reference collects what a laboratory needs to know about ipamorelin as a material: how its five protected residues behave in the vial, what it dissolves in, how it is handled at the bench and what to do when an order arrives. Each section below has its own page.
Molecular reference
| Name | Ipamorelin |
|---|---|
| Also known as | NNC 26-0161 |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 (amidated C-terminus; Aib is 2-aminoisobutyric acid, D-2-Nal is 3-(2-naphthyl)-D-alanine) |
| Residues | 5 |
| Molecular formula | C38H49N9O5 |
| Molecular weight | 711.9 g/mol |
| CAS number | 170851-70-4 |
Formula, molecular weight and CAS number are from PubChem (CID 9831659), and the same figures and sequence appear in the specifications on our Ipamorelin 10 mg product page. The sequence is as published by the group that described the compound (Raun et al., European Journal of Endocrinology, 1998), and the Cayman Chemical insert for the acetate salt gives the same formula, a formula weight of 711.9 and the same synonyms (Cayman Chemical, item 39813).
Three features explain most of its behaviour. Its residues are deliberately unusual: 2-aminoisobutyric acid at position 1, D-amino acids at positions 3 and 4, and an amide instead of a free acid at the end. There is no methionine, cysteine, tryptophan, tyrosine, asparagine, glutamine or aspartic acid, so the oxidation, deamidation and aspartate routes are all absent; the one residue with any such reactivity is the histidine. And with a histidine, a lysine and a free N-terminal amine against no acidic group at all, it carries a net positive charge of about plus 2 at pH 7 by our calculation, which is why it dissolves in water without help.
What it is studied for
Ipamorelin came out of a chemistry programme on growth hormone releasing peptides, as a compound lacking the central Ala-Trp dipeptide of an earlier secretagogue. In primary rat pituitary cells it released growth hormone with potency and efficacy similar to GHRP-6, and antagonist profiling showed it acts through a GHRP-like receptor rather than the growth hormone releasing hormone receptor. In anaesthetised rats and conscious swine it released growth hormone comparably to GHRP-6, and none of the secretagogues tested changed FSH, LH, prolactin or TSH in swine (Raun et al., European Journal of Endocrinology, 1998). The receptor is the growth hormone secretagogue receptor, and the Cayman insert gives binding and signalling figures in cells expressing it: a Ki of 63.4 nM and an EC50 of 46.9 nM, with an EC50 of 1.3 nM for growth hormone release from rat pituitary cells (Cayman Chemical, item 39813).
The point the original authors emphasised was selectivity, which is where the name came from: it released growth hormone without the rise in ACTH and cortisol seen with two related secretagogues (Raun et al., European Journal of Endocrinology, 1998).
In healthy male volunteers given short intravenous infusions, levels were dose-proportional with a terminal half-life of about 2 hours, and each infusion produced a single episode of growth hormone release peaking at about 0.67 hours and then declining (Gobburu et al., Pharmaceutical Research, 1999). Our fuller summary, including the later surgical trial, is in the ipamorelin research page. Ipamorelin is also sold in a blend with CJC-1295, which has its own reference: the CJC-1295 + Ipamorelin research reference.
Stability
Its sequence is about as protected as a short peptide gets. Only the histidine has any oxidation chemistry, and a supplier rates the solid in years. The Ipamorelin stability page covers those routes, freeze-thaw, light and what visible changes mean.
Solubility
A net positive charge of about plus 2 and no hydrophobic burden beyond its naphthyl and phenyl rings mean it dissolves in bacteriostatic water without acid, and a supplier gives a figure for buffer. The Ipamorelin solubility guide explains why, which concentrations dissolve cleanly and what causes haze.
Handling
Bench practice for ipamorelin is mostly about keeping the solution cold, clean and labelled. The Ipamorelin handling page lists the steps and the common mistakes.
On arrival
What a sealed vial should look like, why it travels without an ice pack and where it goes first are on the Ipamorelin on-arrival page.
Storage and reconstitution
Fridge and freezer windows, before and after mixing, are on how long peptides last after mixing, and the blend has its own page: how long CJC-1295 + Ipamorelin lasts. Water volumes and the concentration table for a 10 mg vial are on how much bacteriostatic water for an ipamorelin 10 mg vial.
FAQ
Short answers to the questions researchers ask most about storing, mixing and handling ipamorelin are on the Ipamorelin FAQ.
Where to get it
Vistara Labs supplies Ipamorelin 10 mg as a lyophilised vial for laboratory research, shipped within Canada by Canada Post Xpresspost. It is also sold blended with CJC-1295, covered in the CJC-1295 + Ipamorelin research reference. Certificates are on our lab reports page.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
