"CJC-1295" names two different molecules on the research market, and the difference decides almost every figure attached to them: how often they are injected, how much builds up in the blood, and whether any human study applies at all. This page compares the two. The CJC-1295 dosage page reports the trial doses and vendor figures in full, and Medibact's CJC-1295 guide covers the molecule and its evidence.
The molecule: one addition at the end
| CJC-1295 with DAC | CJC-1295 no DAC (Mod GRF 1-29) | |
|---|---|---|
| Backbone | tetra-substituted GRF(1-29) | tetra-substituted GRF(1-29) |
| C-terminal addition | lysine with 3-maleimidopropionamide | none |
| Length | 30 residues | 29 residues |
| What happens after injection | bonds to cysteine 34 of albumin | circulates free |
| PubChem record | CID 91971820, 3647.2 g/mol | none found under its common names |
| Human studies | two (2006) | none |
The four substitutions are changes to the natural sequence at fixed positions. Jetté's 2005 paper reports that the albumin conjugates showed enhanced stability against DPP-IV, the enzyme that cuts natural GRF(1-29), in vitro, and that the DAC compound was still present in rat plasma beyond 72 hours, attached to albumin within 15 minutes of injection. That albumin attachment is the entire difference between a peptide measured in days and one measured, for its unmodified parent, in minutes. Sermorelin — natural GRF(1-29) without the substitutions — is the approved-era reference for the short form; sermorelin compared with ipamorelin sets out its half-life.
The clock each form runs on
| With DAC | No DAC | |
|---|---|---|
| Human half-life | 5.8–8.1 days (Teichman 2006); 8 days (Ionescu 2006) | not published |
| GH after one injection | raised 2- to 10-fold for 6 days or more | no human data |
| IGF-I after one injection | raised 1.5- to 3-fold for 9–11 days | no human data |
| Schedules in circulation | once weekly, or split twice weekly | one to three injections a day |
The weekly schedule has a consequence the daily one does not: build-up. Using the published half-lives in a one-compartment model:
| Half-life used | Left after 7 days | Weekly build-up (× one dose) | Days to 90% of steady state |
|---|---|---|---|
| 5.8 days | 43% | 1.76 | about 19 |
| 8.0 days | 55% | 2.20 | about 27 |
So a weekly DAC injection is, after the first month, sitting on top of roughly one more dose's worth still in circulation. Teichman's multiple-dose study reported the same thing in its own terms — IGF-I stayed above baseline for up to 28 days, and there was "evidence of a cumulative effect". A short-acting peptide injected daily does not accumulate this way; each injection is largely gone before the next.
What continuous stimulation did to growth-hormone pulses
A concern with a long-acting releasing hormone is that it might flatten the body's natural pulses. Ionescu and Frohman measured this directly: overnight sampling every 20 minutes, before and one week after a single 60 or 90 mcg/kg DAC injection, in healthy men aged 20 to 40. Pulse frequency and size were unchanged; the trough between pulses rose 7.5-fold, mean GH 46% and IGF-I 45%, with no difference between the two doses. No equivalent measurement exists for the no-DAC form.
Weekly totals and units from the same vial
The vendor figures reported on the CJC-1295 dosage page put the two forms at different per-injection amounts but overlapping weekly totals:
| Form | Per injection | Frequency | Per week |
|---|---|---|---|
| With DAC | 1–2 mg (or 0.5–1 mg twice) | weekly | 1–2 mg |
| No DAC | 100–300 mcg | 1–3 times a day | 0.7–6.3 mg |
Reconstitution arithmetic is the same for both: units on a U-100 syringe = mg ÷ mg/mL × 100.
| Vial and water | 2 mg (DAC, weekly) | 1 mg (DAC, split) | 300 mcg (no DAC) | 100 mcg (no DAC) |
|---|---|---|---|---|
| 5 mg + 2 mL (2.5 mg/mL) | 80 units | 40 units | 12 units | 4 units |
| 5 mg + 3 mL (1.67 mg/mL) | 120 units | 60 units | 18 units | 6 units |
| 10 mg + 2 mL (5 mg/mL) | 40 units | 20 units | 6 units | 2 units |
| 10 mg + 3 mL (3.33 mg/mL) | 60 units | 30 units | 9 units | 3 units |
The same vial therefore serves readings twenty times apart depending on which form is in it — which is why a label that says only "CJC-1295" leaves the reading undecided. A 5 mg vial lasts two and a half weeks at 2 mg weekly, and about five and a half days at 300 mcg three times a day. The CJC-1295 reconstitution page works both forms against both vial sizes, and the calculator any other.
The naming problem, on record
In 2009 a Norwegian anti-doping laboratory analysed an unlabelled preparation for police and customs and identified a 29-amino-acid peptide with a C-terminal amide, "consistent with a peptide currently marketed under the name CJC-1295". Jetté's CJC-1295 carries a thirtieth residue with the maleimide group; the seized material, by the abstract's own description, did not. The same paper notes that as a growth-hormone releasing factor CJC-1295 falls under section S2 of the WADA Prohibited List. Distinguishing the forms takes a mass measurement; the name does not do it.
What is not established
No human study of the no-DAC form has been published, so its half-life, its effect on growth hormone and every figure in circulation for it are extrapolations. The DAC trials were small and short, and the only registered trial was terminated without results. Whether a given vial holds either molecule, and how much, is not known without an assay. Nothing on this page is a dose or a schedule.
Sources and dates
Opened 2026-09-27: PubMed abstracts for Jetté et al., Endocrinology 2005 (PMID 15817669), Teichman et al., JCEM 2006 (PMID 16352683), Ionescu and Frohman, JCEM 2006 (PMID 17018654) and Henninge et al., Drug Test Anal 2010 (PMID 21204297), from a PubMed search for CJC-1295, CJC-1293 and DAC-conjugated GRF (34 records); PubChem compound 91971820 (formula, weight, IUPAC name and synonyms) and PubChem name searches for the no-DAC form's common names. Vendor figures as reported on this site's CJC-1295 dosage page (sources read 2026-09-18). The accumulation model, weekly totals and unit figures are arithmetic by this site. Corrections go to the contact page.