CJC-1295: What DAC Changes and What the Evidence Shows
CJC-1295 is sold under one name and comes in two forms that behave nothing alike. A dose of one lasts days; a dose of the other lasts about half an hour. Vendors routinely label both "CJC-1295", which makes this the single most consequential thing to understand before anything else on the page.
DAC or no DAC — the distinction that matters
| CJC-1295 with DAC | CJC-1295 without DAC | |
|---|---|---|
| Also sold as | CJC-1295 DAC, "long-acting" | Modified GRF(1-29), Mod GRF, CJC-1295 no-DAC |
| What DAC does | Binds albumin in the bloodstream, so the molecule is not cleared quickly | No albumin binding |
| Duration per dose | Days — a single dose produced prolonged GH and IGF-I elevation in humans | Roughly 30 minutes: one brief pulse |
| Dosing frequency | Typically once or twice weekly | Typically daily, often before bed |
| Effect on GH pattern | Sustained elevation with pulsatility preserved | Closer to a natural single pulse |
The pulsatility point deserves emphasis because it is often stated backwards. A 2006 study specifically examined whether continuous stimulation from the DAC form flattens the body's natural GH rhythm, and found that pulsatile secretion persists. That is a genuine finding in the compound's favour — but it describes hormone patterns, not outcomes.
How it works
GHRH is the hypothalamic hormone that tells the pituitary to release growth hormone. Its natural form is degraded within minutes, which makes it useless as a drug. CJC-1295 is GHRH(1-29) — the shortest fragment retaining full activity — with amino acid substitutions that resist enzymatic cleavage, plus in the DAC version a linker that attaches it to circulating albumin.
Because it acts upstream on the pituitary rather than replacing GH directly, the body's feedback loops stay intact: somatostatin can still shut a pulse down. That caps how high GH can go, which is a built-in safety margin that injected growth hormone does not have. It is the same architecture as sermorelin andtesamorelin, with a longer duration.
What the human studies found
The evidence here is real but narrow, and it is important to be precise about what it covers:
- Sustained GH and IGF-I elevation. The 2006 study in healthy adults showed a single CJC-1295 dose produced multi-day elevation of both hormones. This is solid human pharmacology and it is the basis for the entire compound.
- Pulsatility preserved. A companion study confirmed natural pulsatile secretion continues under continuous stimulation.
- Class review. A 2018 review of growth hormone secretagogues surveys what human data exists across the category and how thin the outcome evidence is.
Dosing references
| Form | Common amount | Frequency | Basis |
|---|---|---|---|
| CJC-1295 with DAC | 1–2 mg | Once or twice weekly | Practice-derived |
| CJC-1295 no-DAC (Mod GRF) | 100–200 mcg | Daily, often before bed | Practice-derived |
No adult dose-finding trial exists for either form. Bedtime dosing for the short-acting version is not folklore — the largest natural GH pulse occurs in early slow-wave sleep, and a short-acting GHRH dose is timed to reinforce it. Where CJC-1295 is combined with ipamorelin, the blend-vial arithmetic is covered in detail on theCJC-1295 + ipamorelin dosage page.
Formula: concentration = peptide (mcg) ÷ water (ml). Volume = dose ÷ concentration. One unit on a U-100 insulin syringe = 0.01 ml. Values are for laboratory reference only.
Side effects
- Injection-site reactions — redness, itching, swelling; the most common complaint.
- Water retention, joint aches, carpal-tunnel-type symptoms — the classic GH-axis effects, dose-related.
- Flushing and headache shortly after dosing, more often reported with the short-acting form.
- Reduced insulin sensitivity — GH opposes insulin, so sustained elevation is not neutral for glucose.
The class-level caution applies as it does to every GH-axis compound: sustained IGF-I elevation is not a neutral state in the presence of an undiagnosed malignancy. Oursafety overview sets this alongside the other compound classes.
Regulatory status
- Not approved for any indication in any country.
- Not eligible for compounding — FDA restricted GHRH analogs including CJC-1295 as bulk drug substances, so the pharmacy route that exists for sermorelin does not apply here.
- WADA prohibited under section S2.2, which names CJC-1295 explicitly rather than catching it by category.
Research on CJC-1295 + Ipamorelin
6 records in our research database, classified by evidence type:
- HumanThe Safety and Efficacy of Growth Hormone SecretagoguesSigalos JT, Pastuszak AW · Sexual Medicine Reviews, 2018
- HumanSystematic review: the effects of growth hormone on athletic performanceLiu H et al. · Annals of Internal Medicine, 2008
- HumanProlonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adultsTeichman SL et al. · Journal of Clinical Endocrinology & Metabolism, 2006
CJC-1295 — research vial — American Peptides
Sold for laboratory research use, most commonly as a no-DAC blend with ipamorelin. Check which form a listing actually describes — 'CJC-1295' alone does not tell you whether DAC is present, and the two behave completely differently.
We may earn a commission if you buy through this link (at no extra cost to you). Sold for research purposes only.
Frequently asked questions
What is CJC-1295?
CJC-1295 is a synthetic analog of growth hormone-releasing hormone — a modified GHRH(1-29) fragment engineered to resist enzymatic breakdown. It stimulates the pituitary to release its own growth hormone rather than replacing it. It is not approved for any use anywhere.
What is the difference between CJC-1295 with DAC and without DAC?
This is the only distinction that really matters. With DAC (Drug Affinity Complex), the molecule binds to albumin in the bloodstream and a single dose elevates growth hormone and IGF-I for days — a human study measured sustained elevation after one injection. Without DAC — which is chemically the same thing as modified GRF(1-29) — the half-life is roughly 30 minutes, producing a brief pulse. Vendors frequently label the no-DAC version "CJC-1295" without qualification, so the same product name covers two very different pharmacological profiles.
What CJC-1295 dose is used?
No approved dose exists because the compound has no approved use. The human pharmacology studies used weight-based single doses. Community protocols reference roughly 1–2 mg weekly for the DAC form and 100–200 mcg per injection for the no-DAC form, typically before bed. These are practice-derived numbers, not trial-derived ones.
Does CJC-1295 build muscle?
No trial has tested that. It reliably raises growth hormone and IGF-I — that part is documented in humans. Whether raising them produces muscle or strength is a separate question, and the systematic review of growth hormone in athletes found increased lean body mass without improved strength or performance. A compound that works by releasing GH inherits that ceiling.
Is CJC-1295 legal?
It is not FDA approved and is sold as a research chemical. It cannot be legally compounded — FDA placed GHRH analogs including CJC-1295 in the restricted category of bulk drug substances. It is prohibited for tested athletes under WADA section S2.2, which names it explicitly.
Sources
- Teichman SL et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology & Metabolism, 2006;91(3):799–805. PubMed
- Ionescu M, Frohman LA. Pulsatile Secretion of Growth Hormone (GH) Persists during Continuous Stimulation by CJC-1295, a Long-Acting GH-Releasing Hormone Analog. Journal of Clinical Endocrinology & Metabolism, 2006;91(12):4792–7. PubMed
- Sigalos JT, Pastuszak AW. The Safety and Efficacy of Growth Hormone Secretagogues. Sexual Medicine Reviews, 2018;6(1):45–53. PubMed
- Liu H et al. Systematic review: the effects of growth hormone on athletic performance. Annals of Internal Medicine, 2008;148(10):747–58. PubMed
- FDA. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks. FDA
- World Anti-Doping Agency. Prohibited List 2026, section S2.2 — names CJC-1295. WADA Prohibited List
Related guides
- CJC-1295 + Ipamorelin: the blend
- CJC-1295 + Ipamorelin dosage and blend math
- Sermorelin: the shorter-acting former drug
- Tesamorelin: the only approved GHRH analog
- What growth hormone research found about strength