Ask around any research forum and the same question turns up every week: what is the difference between CJC-1295 with DAC and CJC-1295 without DAC? The question keeps coming back because the answer keeps getting given badly — usually as “one lasts longer” and nothing else. That is true and it is not useful, because it does not tell you how to check which one is in front of you.
Here is the version that does. CJC-1295 with DAC vs without DAC is not one compound in two strengths. They are two different molecules with two different molecular formulas, two different masses, and two different CAS registry numbers. Everything else follows from that.
The two molecules, by the numbers
Both compounds are built on the first 29 amino acids of growth hormone–releasing hormone, the fragment usually written GHRH(1-29). Both carry the same four substitutions relative to the native sequence, at positions 2, 8, 15 and 27 — D-alanine, glutamine, alanine and leucine respectively, which you can read straight out of the systematic name on the public chemistry records.
Where they part company is one added group:
| Without DAC | With DAC | |
|---|---|---|
| Molecular formula | C152H252N44O42 | C165H269N47O46 |
| Molecular weight | 3367.9 g/mol | 3647.2 g/mol |
| CAS number | 863288-34-0 | 446262-90-4 |
| PubChem CID | 56841945 | 91971820 |
Subtract one from the other and the difference is 279.3 daltons — a single added albumin-binding group, the “Drug Affinity Complex” the DAC abbreviation stands for. That number is the cleanest way to think about the pair. Not a dose difference, not a purity difference, not a grade. One group, 279.3 daltons, two separate entries in the chemical literature.
It is worth noting what the substitutions do not explain. All four are on both molecules. If someone tells you the difference between the two products is the amino acid substitutions, they have the chemistry backwards.
One more number for context: sermorelin, which is unmodified GHRH(1-29), is C149H246N44O42S at 3357.9 g/mol. Notice the sulfur atom at the end of that formula, and notice that neither CJC formula has one. That is the position-27 substitution showing up in the arithmetic — swapping methionine for leucine removes the only sulfur in the sequence. Three related compounds, and you can tell them apart by formula alone.
Why the naming is a mess, and it is not just vendors
The market gets blamed for the confusion around these names. Some of that is fair. Most of it is inherited.
Search “CJC-1295 without DAC” in PubChem’s name index and you get no record. Search “Modified GRF (1-29)”, the other common name for the same material, and you get no record either. Neither name resolves to anything. You have to search by CAS number to land on the right entry at all.
It gets better. The record for the 29-residue form — CID 56841945, the one whose formula and systematic name unambiguously describe the molecule without the albumin-binding group — lists “CJC 1295 with DAC” and “DAC:GRF acetate” among its synonyms, alongside “CJC-1295-no DAC acetate.” One record, both names, pointing in opposite directions. The molecular formula is the only thing on that page that settles the question, and it settles it decisively.
So when a product label is ambiguous, the label is not necessarily the problem. The naming convention itself is ambiguous, all the way up into the reference databases. Which leads to the only practical conclusion available here.
What actually identifies the material
A product name is a marketing string. It carries no information you can verify. Three things do:
- The CAS registry number. 863288-34-0 and 446262-90-4 are different registry entries for different substances. A listing that gives you a CAS number has told you something falsifiable; a listing that gives you only a name has not.
- The stated molecular weight. 3367.9 versus 3647.2 is a 279-dalton gap. That is not a rounding difference or a salt-form difference. Any analytical document that reports a mass reports which of the two molecules it looked at.
- Whether documentation exists for the exact vial size you are buying, rather than for a different size of the same compound on the same page. This one catches more real problems than the first two combined, and it is the easiest to check.
None of this requires a chemistry background. It requires reading two numbers and comparing them to a public database, which takes about a minute.
The half-life question, stated carefully
The reason anyone distinguishes these two in the first place is pharmacokinetics. In the 2006 clinical study of CJC-1295 published in the Journal of Clinical Endocrinology & Metabolism, the estimated half-life of the compound was 5.8 to 8.1 days (Teichman et al., 2006;91(3):799–805). That is a measured property of the molecule with the albumin-binding group attached, and it is why the two forms are not interchangeable materials in a study design.
Two boundaries around that figure, both of which matter. First, it is a published measurement about a molecule — it is not a statement about any product sold by us or by anyone else, and it is not a recommendation for use in humans. Second, CJC-1295 has never been approved by the FDA for any indication; the clinical program it came from was discontinued. A 2026 review in Frontiers in Endocrinology catalogues both forms explicitly among compounds marketed as research materials and sold without regulatory approval, which is exactly what they are.
Where this leaves you
If you are sourcing either form, the checklist is short. Confirm the CAS number matches the form you want. Confirm the stated mass matches that CAS number. Confirm that batch documentation exists for the size on the invoice, not for a neighbouring size. If a supplier cannot produce those three things, the name on the vial is not evidence of anything.
Forto Research lists CJC-1295 (With DAC) and CJC-1295 (No DAC) as separate catalog entries rather than as options on one page, for the reason this whole article is about — they are separate compounds and merging them into a single listing is where the ambiguity starts. Ipamorelin, the compound most often discussed alongside them, is a different class entirely and is listed separately again. Batch documentation we publish is on our certificate page.
Disclaimer: For research use only. All products mentioned are intended for research and laboratory use only. Not for human consumption. These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.