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CJC-1295 + Ipamorelin and tesamorelin: structural comparison
A two-component blend and a single modified peptide, compared on composition and structure.
These two listings are frequently considered together because both relate to growth hormone-releasing hormone. Structurally they are quite different: one is a two-component blend, the other a single modified peptide.
This page compares what each vial contains, how each relates to the native GHRH sequence, and the formats stocked.
| Property | CJC-1295 + Ipamorelin | Tesamorelin |
|---|---|---|
| Vial contents | Two peptides, published split | One peptide |
| Components | CJC-1295 without DAC, 5 mg; ipamorelin, 5 mg | Tesamorelin |
| GHRH-related component | CJC-1295 without DAC — 29-residue GHRH analogue | 44-residue GHRH analogue |
| Relationship to native GHRH | Truncated to the 1-29 region with four substitutions | Full 44-residue sequence with an N-terminal acyl group |
| Second component | Ipamorelin — pentapeptide, characterized against the growth hormone secretagogue receptor | None |
| Receptor families characterized against | GHRH receptor and GHS receptor | GHRH receptor |
| Key modification | Four substitutions; no DAC moiety | Trans-3-hexenoyl group on the N-terminus |
| Strengths stocked | 5 mg/5 mg | 10 mg |
| Storage | Refrigerated, protected from light | Refrigerated, protected from light |
One vial, two molecules — versus one
The CJC-1295 + Ipamorelin listing is a blend: a 5 mg/5 mg vial holding two distinct peptides. Unlike GLOW and KLOW, this blend publishes its split, and the division is even.
Tesamorelin is a single compound in a 10 mg vial. The two listings therefore hold the same total peptide mass in different arrangements — 10 mg of one molecule versus 5 mg each of two.
That difference governs everything downstream. A blend's reconstitution arithmetic runs against total mass unless the split is known; here it is known, so component-level concentrations can be calculated, which is not the case for GLOW or KLOW.
Two routes to a GHRH analogue
Native growth hormone-releasing hormone is a 44-amino-acid peptide, and both listings contain an analogue of it — but they are built differently.
Tesamorelin retains the full 44-residue sequence and adds a trans-3-hexenoyl group at the N-terminus. That acyl group obstructs the dipeptidyl peptidase-4 cleavage site sterically, addressing stability while leaving the receptor-binding region unmodified.
CJC-1295 without DAC takes the truncation route instead: it uses the 1-29 region, the shortest fragment that retains receptor engagement, with four amino acid substitutions for stability. It is also catalogued as modified GRF(1-29).
The 'No DAC' designation is worth understanding. DAC is a drug affinity complex moiety that can be appended to extend circulating half-life considerably. This blend uses the version without it, which is a different molecule from CJC-1295 with DAC and should not be conflated with it.
The second receptor
Ipamorelin, the blend's other component, is not a GHRH analogue at all. It is a pentapeptide — five residues — characterized against the growth hormone secretagogue receptor, the receptor family that also binds ghrelin.
That means the blend engages two distinct receptor families where tesamorelin engages one. This is a compositional fact about what is in the vial rather than a statement about what follows from it.
Ipamorelin is also stocked as a single-compound 10 mg listing. Within the blend it is present at 5 mg, so the standalone listing carries twice the mass of the blend's ipamorelin component.
Reconstitution: a known split changes the arithmetic
For tesamorelin the calculation is the ordinary one: 10 mg divided by the diluent volume. Adding 1 ml gives 10 mg per ml; 2 ml gives 5 mg per ml.
For the blend, the published split makes component-level arithmetic possible. Reconstituting the 5 mg/5 mg vial with 1 ml gives 10 mg per ml of combined material, which is simultaneously 5 mg per ml of CJC-1295 without DAC and 5 mg per ml of ipamorelin. Because the split is stated, both figures are specification rather than inference.
That is the practical difference from GLOW and KLOW, where no split is published and only a blend-level concentration can be derived. It is worth noting that a published split is a property of the individual listing rather than of blends in general.
peptcalc.com handles either basis — enter the total mass for a blend-level figure, or a component mass where the split is known.
Storage and documentation
Both are supplied lyophilized and ambient-stable in transit, so neither ships with a cold chain or insulated packaging. Both are refrigerated on arrival and kept out of light, and reconstituted material is held cold and used within the window the receiving facility's protocols specify.
The blend's stability window is governed by whichever of its two components is least stable, which is the general rule for multi-component solutions.
Their certificates differ in shape. Tesamorelin's is a single-compound document: one identity confirmation, one purity percentage, one chromatogram with a main peak. The blend's covers two molecular entities, so its chromatogram shows two principal peaks by design and a single headline purity figure does not carry the same meaning.
Where component-level documentation is needed for the blend, ipamorelin is stocked separately with its own certificate.