Tesamorelin vs CJC-1295: Two Modified GHRH Analogs Compared

Same parent, different strategies

Natural GHRH is a 44-residue peptide that enzymes such as dipeptidyl peptidase-4 cut quickly near the N-terminus. Both analogs were designed to resist that cleavage.

Tesamorelin keeps all 44 residues and attaches a trans-3-hexenoyl group to the N-terminal tyrosine. CJC-1295 starts from the shorter GHRH(1-29) fragment, swaps four residues (D-Ala2, Gln8, Ala15, Leu27) to resist enzymes and oxidation, and adds a lysine carrying a maleimide linker, the Drug Affinity Complex (DAC), which the literature describes as binding covalently to albumin.

Size at a glance

• Tesamorelin: trans-3-hexenoyl-GHRH(1-44)-NH2, formula C221H366N72O67S, listed molecular weight 5135.9 Da.
• CJC-1295 with DAC: modified GHRH(1-29) with DAC, listed molecular weight 3647.1 Da.
• Relative: Sermorelin is the unmodified GHRH(1-29)-NH2 fragment, about 3358 Da.

What the literature examines

Both are studied as GHRH-receptor agonists. Tesamorelin papers compare it with native GHRH and look at stability and receptor activity. CJC-1295 papers focus on how albumin binding changes how long the compound stays in circulation in animal and early clinical pharmacology studies.

The Tesamorelin and CJC-1295 research overviews summarize the literature with citations.

Checking each one in the lab

At 3.6 to 5.1 kDa, both appear in electrospray mass spectra as a series of multiply charged ions, so the mass has to be reconstructed from several charge states. Tesamorelin keeps the native methionine at position 27, so a +16 Da shift points to Oxidation; CJC-1295 replaces that methionine with leucine, one of its four substitutions.

Larger peptides like these are more prone to Aggregation in solution; the solubility and aggregation guide covers what to watch for.

Handling notes

Both are stored sealed and frozen as lyophilized powders. For solution arithmetic with each listed molecular weight, see the Tesamorelin and CJC-1295 with DAC calculators.