GHRH analogues, as a family.
Sermorelin, CJC-1295 in both forms and tesamorelin are all versions of one human hormone, growth-hormone-releasing hormone, and each is defined by exactly how it departs from the original. Read as a family rather than four separate names, the catalog becomes easy to decode: which residues were kept, which were swapped and what was attached to the ends.
GHRH, 44 residues.
Human growth-hormone-releasing hormone is a 44-amino-acid peptide with an amidated C-terminus, made in the hypothalamus, with the sequence YADAIFTNSYRKVLGQLSARKLLQDIMSRQQGESNQERGARARL-NH2. Work in the 1980s showed that the first 29 residues carry the full activity of the hormone in receptor assays, and that the chain is cut quickly in blood by the enzyme DPP-IV between residues 2 and 3. Every analogue in the family is an answer to one of those two facts: keep the 1-29 core, or protect the second residue.
Four analogues, one table.
| Sermorelin | GHRH(1-29)-NH2: the first 29 residues, unchanged. C149H246N44O42S, 3357.9 g/mol |
|---|---|
| Mod GRF 1-29 (CJC-1295 without DAC) | GHRH(1-29)-NH2 with four substitutions: D-Ala at 2, Gln at 8, Ala at 15, Leu at 27. C152H252N44O42, 3367.9 g/mol |
| CJC-1295 with DAC | Mod GRF 1-29 with a lysine at position 30 carrying a maleimidopropionic acid linker, the Drug Affinity Complex, that binds serum albumin |
| Tesamorelin | GHRH(1-44)-NH2 with a trans-3-hexenoyl group on the N-terminal tyrosine; 5136 g/mol |
| Not in the family | Ipamorelin, GHRP-2, GHRP-6 and hexarelin act at the ghrelin receptor, not the GHRH receptor |
The core, unchanged.
Sermorelin is GHRH(1-29) with an amidated C-terminus and nothing else altered: 3357.9 g/mol, 29 residues. It was developed in the 1980s and approved as a prescription drug in the United States in the 1990s before being withdrawn from the market in 2008 for commercial rather than safety reasons. Because it keeps the native Ala at position 2, it is cut by DPP-IV as quickly as the parent hormone. The sermorelin page covers its identity data, and sermorelin vs CJC-1295 compares it with the next analogue.
Four substitutions, no tail.
Modified GRF 1-29 takes sermorelin's sequence and changes four residues: D-alanine at position 2 blocks the DPP-IV cut, glutamine at 8 replaces an asparagine that deamidates, alanine at 15 replaces a glycine for a more stable helix, and leucine at 27 replaces a methionine that oxidizes. The mass moves to 3367.9 g/mol. This is the molecule most catalogs mean by CJC-1295 without DAC, and it is the CJC-1295 in Helion's CJC-1295 + ipamorelin blend. CJC-1295 DAC vs no DAC walks through the naming confusion.
The same core with an albumin hook.
CJC-1295 as originally published adds a thirtieth residue, lysine, whose side chain carries a maleimidopropionic acid group. The maleimide reacts with the free thiol of serum albumin's cysteine 34, so the peptide rides on albumin in blood; the developers called the attachment a Drug Affinity Complex, DAC for short. The four substitutions are the same as Mod GRF 1-29. Identity testing tells the two apart by mass: the DAC form is several hundred daltons heavier.
The full chain with a lipid cap.
Tesamorelin keeps all 44 residues of the parent hormone and adds a trans-3-hexenoyl group, a six-carbon chain with one double bond, to the amino group of the N-terminal tyrosine. The cap slows the DPP-IV cut without changing any residue. At 5136 g/mol it is the largest member of the family and the only one approved as a prescription drug in the United States today, since 2010. The tesamorelin page lists its identity data; tesamorelin vs CJC-1295 and tesamorelin vs sermorelin vs ipamorelin compare it with the others.
Which GHRH analogue is in the vial.
Three checks settle it. The residue count: 29 for sermorelin and Mod GRF 1-29, 30 for CJC-1295 with DAC, 44 for tesamorelin. The mass on the lab report, which separates all four. And the name: a catalog that says CJC-1295 without saying DAC or no DAC should be asked which it means. How to read a peptide sequence explains the notation, and mass spectrometry for peptide identity explains the mass check.
Two of the four.
Helion supplies tesamorelin 5 mg and CJC-1295 (no DAC) with ipamorelin, each with a third-party report for the lot in the COA Portal.
Specs and storage by compound.
Questions (6)
What is a GHRH analogue?
A synthetic version of human growth-hormone-releasing hormone, usually built on its first 29 residues, altered to resist enzymatic cutting or to last longer in blood.
Is sermorelin the same as CJC-1295?
No. Sermorelin is GHRH(1-29) unchanged; Mod GRF 1-29, the usual CJC-1295 without DAC, has four residue substitutions, and CJC-1295 with DAC adds a thirtieth residue carrying an albumin-binding linker.
What does DAC mean in CJC-1295?
Drug Affinity Complex: a maleimidopropionic acid group on a lysine at position 30 that attaches the peptide to serum albumin.
How is tesamorelin different from sermorelin?
Tesamorelin is the full 44-residue hormone with a trans-3-hexenoyl cap on its first residue; sermorelin is the first 29 residues with no cap.
Is ipamorelin a GHRH analogue?
No. Ipamorelin acts at the ghrelin receptor and is a different class of molecule, which is why it is paired with CJC-1295 in blends rather than compared with it.
Which GHRH analogues does Helion sell?
Tesamorelin 5 mg, and CJC-1295 (no DAC) in a blend with ipamorelin.
Published studies (2)
- Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly
- Pharmacokinetics, safety, and endocrine and appetite effects of ghrelin administration in young healthy subjects
Citations from PubMed for reference. They describe the compound in the literature, not any Helion lot, and nothing here is guidance on use.