CJC-1295 DAC vs No-DAC: Dosing and Units
Last updated: July 2026
CJC-1295 with DAC is a long-acting growth-hormone-releasing hormone (GHRH) analog: an added albumin-binding group stretches its half-life to roughly a week, so it is injected only about once or twice weekly. CJC-1295 without DAC — the peptide sold as "no-DAC" or Modified GRF 1-29 — lacks that albumin anchor, clears in well under an hour, and is therefore taken in small amounts one to three times a day. Yet the number of syringe units you draw depends only on how you reconstitute the vial, not on which version you hold.
Have a vial and a target dose in micrograms? Convert it to exact mL and U-100 syringe units in seconds.
Peptide reconstitution calculator →TL;DR — key takeaways
- DAC = "Drug Affinity Complex." It is a chemical group that bonds CJC-1295 to your own blood albumin, which is the single reason the two versions are dosed on completely different schedules.
- With DAC: long-acting, dosed weekly. A single injection raised growth hormone for 6+ days and IGF-I for 9–11 days in the published human study, with a half-life of about 6–8 days.
- Without DAC (Mod GRF 1-29): short-acting, dosed daily. Like sermorelin, it produces a brief GH pulse that clears in minutes, so protocols split it into frequent small doses.
- Units follow concentration, not the drug. A 100 mcg dose is 10 units from one vial and 5 units from another — whichever version it is.
- Neither is FDA-approved for these uses. They are research peptides; "CJC-1295 no-DAC" is a community label for tetra-substituted GRF 1-29, and its human pharmacokinetics are inferred from sermorelin, not directly published.
What the "DAC" actually does
Both versions share the same active GHRH sequence — a modified fragment of the first 29 amino acids of natural GHRH, the same fragment used in sermorelin. The difference is a bolt-on. The DAC version carries a maleimide-based linker that forms a stable covalent bond with cysteine-34 on circulating albumin the moment it enters the bloodstream. Albumin is a large, long-lived carrier protein, so tethering the peptide to it shields the peptide from the enzymes that would otherwise chew it up in minutes.
The result is dramatic. In the pivotal human study of the DAC version, a single subcutaneous injection produced a peptide half-life of 5.8–8.1 days, kept mean GH elevated 2- to 10-fold for six days or more, and held IGF-I above baseline for up to 28 days after repeated dosing. Strip the DAC off and you are left with a peptide that behaves like sermorelin, whose action is measured in minutes — hence the daily, multi-dose schedules used with Mod GRF 1-29.
Side-by-side: DAC vs no-DAC
| Property | CJC-1295 with DAC | No-DAC (Mod GRF 1-29) |
|---|---|---|
| Albumin binding | Yes (covalent, via DAC) | No |
| Approx. half-life | ~6–8 days | ~30 minutes (minutes) |
| Typical dose frequency | 1–2× per week | 1–3× per day |
| GH release pattern | Sustained "bleed" over days | Sharp, short pulse |
| Core sequence | Modified GRF 1-29 | Modified GRF 1-29 |
| Route | Subcutaneous | Subcutaneous |
| Regulatory status | Not FDA-approved | Not FDA-approved |
The two columns describe the same molecule with and without one attachment — the same GHRH signal delivered on opposite timescales.
The two release patterns, visualised
Plotted against time, the DAC version is a broad plateau and the no-DAC version is a series of narrow spikes. Both raise growth hormone; they simply do it on different clocks.
The pulse shape matters clinically: short-acting GHRH analogs like sermorelin are argued to better mimic the body's natural pulsatile GH rhythm, while the DAC version keeps a continuous elevation — which one human study found still preserved underlying GH pulses rather than flattening them.
Turning any dose into syringe units
Peptides are dosed in micrograms (mcg), but a U-100 insulin syringe reads in units, where 1 unit = 0.01 mL. The conversion never changes: work out the concentration in mcg per mL, divide your dose by it to get mL, then multiply by 100 for units. A shortcut worth memorising: at any concentration, mcg per unit = (mg/mL) × 10.
Worked example 1 — DAC, weekly dose
A 2 mg CJC-1295 DAC vial reconstituted with 1 mL BAC water = 2 mg/mL = 2000 mcg/mL, so each unit holds 20 mcg.
A 1000 mcg weekly dose: 1000 ÷ 2000 = 0.5 mL × 100 = 50 units, drawn once per week.
Worked example 2 — no-DAC, per-dose
A 5 mg Mod GRF 1-29 vial with 2.5 mL BAC = 2 mg/mL = 2000 mcg/mL → 20 mcg per unit.
A 100 mcg dose: 100 ÷ 2000 = 0.05 mL × 100 = 5 units — a tiny draw, because this version is taken several times a day.
Worked example 3 — same dose, more water
The same 5 mg no-DAC vial with 5 mL instead: 1 mg/mL = 1000 mcg/mL → 10 mcg per unit.
Now that 100 mcg dose = 100 ÷ 1000 = 0.1 mL = 10 units. Double the water, double the units — for the identical 100 mcg.
Worked example 4 — watch the 1 mL ceiling
A 2 mg DAC vial with 2 mL = 1 mg/mL = 1000 mcg/mL → 10 mcg per unit. A 1000 mcg weekly dose becomes 1000 ÷ 1000 = 1 mL = 100 units — the entire barrel of a 1 mL syringe.
Add more water than that and a single dose no longer fits one syringe. Using less water keeps the draw small.
Worked example 5 — weekly totals are not equal
DAC at 1000 mcg once weekly = 1000 mcg per week. No-DAC at 100 mcg twice daily = 100 × 2 × 7 = 1400 mcg per week.
The versions are not milligram-for-milligram interchangeable; their schedules deliver different weekly totals, so never map one dose straight onto the other.
Worked example 6 — a per-kg research dose
The human DAC study used up to 30 mcg/kg. For an 80 kg adult that is 2400 mcg. At 2 mg/mL (20 mcg/unit): 2400 ÷ 2000 = 1.2 mL = 120 units — past a 1 mL syringe, so it would be split or drawn from a stronger vial.
Dose-to-units reference chart
Common per-injection doses shown as units on a U-100 syringe at two typical reconstituted strengths. Confirm every figure against your own vial label.
| Dose | At 1000 mcg/mL | At 2000 mcg/mL |
|---|---|---|
| 50 mcg | 5 units | 2.5 units |
| 100 mcg | 10 units | 5 units |
| 200 mcg | 20 units | 10 units |
| 300 mcg | 30 units | 15 units |
| 500 mcg | 50 units | 25 units |
| 1000 mcg (1 mg) | 100 units | 50 units |
| 2000 mcg (2 mg) | — (over 1 mL) | 100 units |
Small no-DAC doses land at the bottom of the chart; larger weekly DAC doses climb toward the 1 mL ceiling, which is exactly why the water volume you choose is part of the dose.
How this is calculated
Every number above uses two facts only: a U-100 syringe holds 100 units per mL, and concentration is dose divided by volume. There is no compound-specific constant — the arithmetic is identical whether the vial is DAC or no-DAC. The half-life and dose-frequency figures come from the published literature cited below; the unit conversions are plain division you can check by hand. None of this is medical advice — it is the maths behind a dose your prescriber has set.
An honest note on status
CJC-1295 (both versions) is not approved by the FDA for growth-hormone enhancement, anti-aging, or body composition. The only closely related GHRH analog on the US market is tesamorelin (Egrifta), approved narrowly for HIV-associated lipodystrophy and dosed 1.4 mg once daily. "CJC-1295 no-DAC" is a research-community name rather than a formal drug, and its short half-life is inferred from sermorelin and GRF 1-29 pharmacology rather than a dedicated published human study. Treat any dosing figure here as arithmetic to understand a protocol, not an endorsement to run one.
Frequently asked questions
Is CJC-1295 no-DAC the same thing as sermorelin?
They are close cousins. Both are short-acting analogs of GRF 1-29 that clear in minutes and produce a brief GH pulse. No-DAC (Mod GRF 1-29) carries a few amino-acid substitutions for extra stability, but its dosing rhythm — small, frequent doses — mirrors sermorelin.
Why is the DAC version dosed weekly and the other daily?
Only the DAC version binds to albumin, which extends its half-life to roughly 6–8 days. Without that anchor the peptide is degraded within about half an hour, so it has to be re-dosed several times a day to keep any effect going.
Do I draw more units for the DAC version?
Not because of the DAC. Units depend on the vial concentration and your target dose, not the label. A large weekly DAC dose usually means more units per injection simply because the dose is bigger, while no-DAC doses are small and frequent.
Can I convert my no-DAC dose straight to a DAC dose?
No. The two run on different schedules and weekly totals, so there is no clean one-to-one swap. A change of version is a protocol decision for your prescriber, who will set a new dose and frequency.
Sources
- Teichman SL, et al. Prolonged Stimulation of GH and IGF-I Secretion by CJC-1295, a Long-Acting Analog of GHRH, in Healthy Adults (J Clin Endocrinol Metab 2006)
- Ionescu M, Frohman LA. Pulsatile Secretion of GH Persists During Continuous Stimulation by CJC-1295, a Long-Acting GHRH Analog (J Clin Endocrinol Metab 2006)
- Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic GH deficiency (BioDrugs 1999)
- Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? (Clin Interv Aging 2006)
- Sinha DK, et al. Beyond the androgen receptor: the role of growth hormone secretagogues in body composition (Transl Androl Urol 2020)
- EGRIFTA SV (tesamorelin) Prescribing Information — a marketed GHRH analog (DailyMed / FDA label)
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue (Eur J Endocrinol 1998)
This guide is for general educational purposes only and does not constitute medical advice. Always follow your prescriber’s specific instructions and consult a qualified clinician before changing any protocol.