CJC-1295 half-life and steady state
30 min modelled half-life, peaking 12 min after a dose. What that means for how long it lasts, how much it builds up, and when bloodwork is worth drawing.
- Also known as
- Mod GRF 1-29 (without DAC)
- Class
- Peptides
- Modelled half-life
- 30 min
- Time to peak
- 12 min
- Formulation
- Aqueous (reconstituted powder)
- Cleared per dosing interval
- 100% gone, 0% still present after 24 h
- Time to steady state
- ~2.5 h (about five half-lives)
- Accumulation at that cadence
- 1× — effectively none; each dose clears before the next
- Peak-to-trough at steady state
- Not meaningful — the level returns to zero between doses, so there is no trough to divide into a peak
- Regulatory status
- Research compound — no FDA approval. Not for human use label.
- Monitoring panel
- IGF-1 every 3 months. Fasting glucose.
- Before mixing
- Sealed powder tolerates room temperature in transit, but keep it refrigerated at 2–8 °C (36–46 °F) for anything beyond a few weeks, or frozen for months. Keep it dark — the carton it shipped in is doing a job.
- After mixing
- Once reconstituted with bacteriostatic water: refrigerate at 2–8 °C and use within about 28 days. The benzyl alcohol in bacteriostatic water is what buys that window — plain sterile water has no preservative, so a vial mixed with it should be treated as one sitting only. Kits are usually ten vials: only the one you mixed is on that 28-day clock — the sealed ones keep their own, much longer shelf life, so store them as powder, not as solution.
- What ruins it
- Do not freeze a reconstituted vial. Repeated freeze–thaw is one of the more reliable ways to degrade a peptide.
- Handling caveat
- General handling practice for this formulation. Your supplier’s own insert or COA overrides anything here.
The thirty-minute half-life on this page is the single most misread number in peptide pharmacokinetics, because two very different compounds are sold under the name CJC-1295. What this page describes is CJC-1295 without DAC — also called modified GRF (1-29) — which is cleared in under an hour. CJC-1295 with DAC carries a linker that binds it to albumin and has a half-life of about a week: two hundred times longer. Buying one when you meant the other is not a minor substitution.
A half-hour half-life is not a defect here; it is the design. CJC-1295 without DAC is a GHRH analogue, and growth hormone is released in pulses. A brief spike of GHRH produces a pulse and then gets out of the way, letting the pituitary's own feedback reassert itself. A version that lingered for a week would flatten the pulse into a plateau — which is what the DAC version does, and is precisely the criticism made of it. The pulsatile pattern is thought to matter, so the short half-life is doing work.
Practically: there is no accumulation and no steady state. Each dose is independent, which is why the schedule is timed rather than merely counted — fasted, before bed, to land the pulse alongside the body's own nocturnal one, and away from food because circulating insulin blunts growth hormone release. The pairing with ipamorelin is mechanistic rather than pharmacokinetic: the two act on different receptors and the combination produces a larger pulse than either alone. Both are research compounds with no approval for human use.
One dose
pkCurve function — a
one-compartment absorption-and-elimination model with the absorption rate fitted so the
peak lands at the published time to peak.Dosed once daily
Charted at once daily because that is the once-daily pre-bed schedule in the app's own dosing rows. It is what the numbers below are indexed to, not a recommendation about frequency — that is a prescribing decision.
The arithmetic behind those numbers
fraction left after one interval = 2^(−48.00) = 0.000
accumulation ratio = 1 ÷ (1 − 0.000) = 1
time to steady state ≈ 5 × half-life = 2.5 h
peak-to-trough = not meaningful; the trough is 0 of a single dose's peak, i.e. cleared
The accumulation ratio is a closed form; the peak-to-trough figure is not. The generator adds up enough repeated curves for the total to stop changing, then reads the highest and lowest points of the last interval — which is what steady state means in practice. The vertical axis is relative, not a concentration: the shape and the ratios carry across people, the absolute levels do not.
Interaction rules that name CJC-1295
From the app's own interaction data. Not exhaustive, and not a safety clearance — a combination that is not listed is one nobody has documented here, which is not the same as one that is fine. The full combination checker has the rest.
Gold Standard GH Secretagogue Pairing
CJC-1295 (GHRH analogue) and Ipamorelin (selective GHRP) are the gold standard GH secretagogue combination. CJC-1295 primes pituitary somatotrophs while Ipamorelin triggers GH release with minimal cortisol or prolactin elevation. Always pair these — neither is as effective alone.
What to watch: IGF-1 every 3 months. Fasting glucose. No prolactin monitoring needed with Ipamorelin.
Metformin + GH Secretagogues — Monitor Glucose
GH secretagogues can reduce insulin sensitivity while metformin improves it. The two may partially offset each other's metabolic effects. Metformin can act as a useful safety net for glucose management when using GH peptides long-term.
What to watch: Fasting glucose, HbA1c, IGF-1. The combination is reasonable — just monitor metabolic markers.
Never Combine CJC-1295 and CJC-1295 DAC
These are two forms of the same compound. Combining them dramatically elevates IGF-1 and GH beyond safe physiological ranges. Use one or the other — not both.
What to watch: IGF-1, fasting glucose. If accidentally combined, stop both and recheck IGF-1 in 2 weeks.
The dosing rows this cadence came from
Off-label or community practice Reproduced from the app's entry so you can see what the chart above is indexed to. Which row applies to a particular person, if any, is a clinical decision this page does not make.
| Label | Amount | Route and frequency |
|---|---|---|
| Starting | 100mcg CJC + 100mcg Ipa | Once daily before bed SubQ fasted |
| Optimized | 200mcg CJC + 200mcg Ipa | Twice daily fasted (AM + pre-bed) |
When to draw bloodwork
The panel the app records for CJC-1295 is: IGF-1 every 3 months. Fasting glucose.. The pharmacokinetic point is the timing rather than the list: after any change, a level takes about 2.5 h to settle, so a panel drawn sooner measures something still moving. And because this compound clears completely between doses, a serum level says only what the last few hours did — which is why the marker worth following here is a downstream one measured over weeks, not the compound itself. Whether a result means anything is a question for the clinician who ordered it, read against the reference range your own lab printed. The lab-marker pages cover what the individual analytes measure.
Related: the interactive half-life calculator to try other cadences.
The app draws this curve from the doses you actually logged — your dates, your cadence — and projects seven days forward from the last one.
Save this dose to your log