Ipamorelin: identity and what to check before buying

Ipamorelin is a synthetic pentapeptide with the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2, CAS 170851-70-4, formula C38H49N9O5 and a calculated mass of 711.85 g/mol. Three of its five residues are non-natural. It has no marketing authorisation in the UK or the EU, and those unusual residues are what a certificate has to demonstrate.

Nomenclature and what the class name means

Ipamorelin was described in the endocrinology literature in the second half of the 1990s; one of the early reports appeared in the European Journal of Endocrinology in 1998 (PubMed 9849822). It is discussed there as a ligand at the ghrelin receptor. That is a classification of the molecule as studied in a laboratory, and naming it here is nomenclature rather than a claim: it describes what the compound binds in an assay and says nothing about what any vial contains or does. Peptorium does not summarise the published work, does not transfer it to people or animals and runs no clinical research.

The name is used without variants, which makes it unusually easy to search - but the compound has no common abbreviation, so listings sometimes pair it with other peptides in a blend. A blend is not this product and cannot share this product's certificate.

Identity: three residues that do not occur in proteins

The sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH₂. Three of the five positions are unusual. Aib is alpha-aminoisobutyric acid, which is not one of the twenty residues found in ordinary proteins. D-2-Nal is a D-configured 3-(2-naphthyl)alanine. D-Phe is the D-enantiomer of phenylalanine. The C-terminus is a primary amide rather than a free acid. The public record gives the formula C₃₈H₄₉N₉O₅ and a mass of about 711.9: PubChem CID 9831659.

Those details matter to a buyer for one specific reason. A D-amino acid and its L-form have exactly the same mass, so a mass spectrum cannot tell them apart. A synthesis that used the wrong enantiomer at position three or four produces a compound with the right formula, the right mass and a clean-looking chromatogram. Only chiral analysis, or a supplier who can evidence the starting materials, addresses that. Almost no certificate in this trade does. It is worth knowing which questions the standard document cannot answer, and this is the clearest example on the site.

Regulatory status in the UK and the European Union

Ipamorelin has no marketing authorisation. It does not appear in the EMA medicines database and it is not licensed in the United Kingdom. Under regulation 46 of the Human Medicines Regulations 2012 a person may not sell, supply or offer an unauthorised medicinal product, and regulation 2 defines a medicinal product by presentation as well as by function - so the wording beside a product can place it inside the definition on its own. Anti-doping lists are maintained separately by sporting bodies and are read there.

"Research use only" is a purpose, not a permission

The phrase records that the seller offers the material for laboratory work and not for use in people. It is not a category in UK or EU law, not a licence, and not a review by any authority. It is not a quality claim either, and where a listing offers it instead of naming who made the material and what was measured, it has substituted a disclaimer for disclosure.

Purity, peptide content and a short sequence

Purity by HPLC is the share of separated peak area belonging to the target. Peptide content is the share of the vial's mass that is peptide at all, the remainder being residual water and counter-ions from synthesis, usually acetate or trifluoroacetate. Water is measured separately by Karl Fischer titration, and neither figure can be derived from the other.

A five-residue chain is short, which makes a high purity figure easier to reach than it would be for a long peptide - so the number is less informative here, not more. What is informative is the mass, the impurity table and the evidence of correct stereochemistry. The purity guide and the certificate guide set out the rest.

What Peptorium publishes about this material

This page publishes identity: the sequence, the molecular formula and a calculated mass of 711.85 g/mol. Each of those can be checked against a public register rather than taken on trust. Purity, peptide content and water describe one batch rather than a compound. Those figures belong on a certificate of analysis issued by the laboratory that tested that batch, and they travel with the material itself.

What to ask before buying

• Does the certificate report a measured mass beside the theoretical 711.85 g/mol?
• Is the C-terminus specified as an amide? An acid form differs by one dalton.
• What evidence is there for the D-configured residues at positions three and four? Mass alone cannot show it.
• Is there a batch number, and a certificate for that batch rather than one reused across the product?
• Are impurity peaks listed with a chromatogram?
• Is peptide content stated separately from purity, with water by Karl Fischer, and are the method and date named?

What is not known

• Stereochemistry is not addressed by a standard certificate, so for this compound the usual document leaves a real question open.
• What a particular vial contains cannot be known without analysing it.
• Storage guidance is handling convention, not a stability measurement on a given lot.

Frequently asked questions

The lyophilisate is dissolved in bacteriostatic water, and the volume of solvent chosen fixes the concentration of the solution; the peptide calculator converts between vial content, solvent volume and concentration, and recommends no quantity for any purpose. Material described here is for laboratory and in vitro research use only - see the research declaration.