Tesamorelin vs ipamorelin.

Different receptors, different chains.

Tesamorelin is a GHRH analogue: the full 44-amino-acid sequence of human growth hormone-releasing hormone with a trans-3-hexenoyl group added at the N-terminus, which protects it from the rapid enzymatic cleavage that limits the native hormone. It binds the GHRH receptor.

Ipamorelin is a pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH₂, that binds the growth hormone secretagogue receptor (GHS-R1a), also called the ghrelin receptor. Its 1998 paper described it as the first selective growth hormone secretagogue. The two compounds therefore sit on two separate routes into the same system, which is the main difference between them; the GHRH analogues guide and GHRPs explained cover each class.

The two compounds at a glance.

Formulas, weights and CAS numbers from PubChem (read 11/12/2026). Tesamorelin is about seven times heavier than ipamorelin.

What each one is built from.

Tesamorelin uses only standard amino acids in the 44-residue chain, so its size comes from length. The N-terminal hexenoyl cap and the C-terminal amide are its two modifications; the N-terminus vs C-terminus guide explains both ends. Long chains like this one carry several asparagine, glutamine and methionine residues, the sites that age first in solution, which the peptide stability guide covers.

Ipamorelin is short but unusual. Three of its five residues are non-standard: Aib (alpha-aminoisobutyric acid) and two D-amino acids, D-2-naphthylalanine and D-phenylalanine. D-residues resist the enzymes that cut ordinary L-chains, which the D-amino acids guide explains. Because these residues have no one-letter code, a standard sequence calculator cannot weigh ipamorelin; its 711.9 g/mol comes from PubChem.

What each one is studied for.

Tesamorelin's published record centers on GHRH receptor signaling and the growth hormone and IGF-1 axis; a 2009 review summarizes its development as a growth hormone-releasing factor analogue. Ipamorelin's early papers cover its receptor selectivity (1998) and pharmacokinetic-pharmacodynamic modeling (1999). Because the GHRH receptor and the ghrelin receptor are separate routes, research models sometimes pair a compound from each class, which is the logic behind Helion's CJC-1295 + Ipamorelin blend.

For the wider family see tesamorelin vs sermorelin vs ipamorelin, tesamorelin vs CJC-1295 and CJC-1295 vs ipamorelin.

Telling them apart by identity.

• Mass. At 5136 and 711.9 g/mol the two are impossible to confuse by mass spectrometry. Electrospray shows tesamorelin as a ladder of multiply charged ions, while ipamorelin appears mainly as its singly and doubly charged ions; the mass spectrometry guide shows how to read both.
• HPLC. Each lab report gives the purity of the main peak; the chromatogram guide explains what the number covers.
• Net content. Both are usually supplied as acetate salts, so the powder weighs more than the peptide inside; see purity vs content.

What Helion supplies.

Helion carries Tesamorelin 5mg (vial code TSM5) and the CJC-1295 (No DAC) + Ipamorelin 10mg blend (CP10), whose lot 335XA tested 99.85% HPLC purity at ILS Laboratories. Ipamorelin is sold only inside that blend. Helion supplies these compounds as lyophilized research reference materials for laboratory use only, to buyers 21 and over. Published lab reports are in the COA Portal.

Specs and storage by compound.