CJC-1295 and Ipamorelin: What DAC Actually Changes

“CJC-1295 and Ipamorelin” is the most commonly written peptide pairing there is, and the most commonly written ambiguously. The problem is not the pairing. It is that “CJC-1295” names two compounds that clear on completely different timescales — one persists for days, the other is short-acting — and a protocol that omits the suffix does not contain enough information to follow.

Three compounds, two jobs

The pairing logic is real pharmacology, and worth understanding before the units. Growth hormone release is governed by two opposing signals, and the two peptide classes act on different ones:

• A GHRH analogue — CJC-1295, in either form — mimics growth-hormone-releasing hormone, raising the size of a release pulse.
• A GHRP / secretagogue — Ipamorelin — acts at the ghrelin receptor, a separate pathway.

Because they act through different receptors, the pairing is not simply additive dosing of the same thing, which is the usual justification given for running them together. Ipamorelin is specifically noted for being selective — comparatively little effect on cortisol and prolactin relative to older GHRPs — which is why it displaced them in circulating protocols.

DAC is the whole story

DAC stands for Drug Affinity Complex: a modification that binds the peptide to serum albumin so it persists for days rather than clearing rapidly. That single change produces two compounds that share a name and share almost nothing else.

Read the dose row and the frequency row together. The DAC form is dosed roughly ten times higher and roughly ten times less often. Apply a no-DAC daily schedule to DAC material and you have compounded both errors in the same direction.

The naming is worse than the pharmacology

Strictly, the compound sold as “CJC-1295 without DAC” is modified GRF(1-29) — the original CJC-1295 was the DAC-bearing molecule, and the name was retrospectively applied to the un-modified peptide by vendors. So the more accurate name, Mod GRF 1-29, is the less common one, and the ambiguous name won.

Practically, this means you cannot resolve the ambiguity by reasoning about which is “the real” CJC-1295. You have to look at the vial, or at the dose and frequency in the protocol. A schedule of one to three times daily at 100–300 mcg is describing the short-acting form regardless of what it is labelled. A schedule of once or twice weekly at 1–2 mg is describing DAC. If a protocol gives a dose but no frequency, it is not a protocol.

Worked reconstitutions

Here is the practical consequence, using the same vial and the same volume of water for all three, so the only variable is the dose.

Ipamorelin — 5 mg vial, 2 mL of water

• Concentration: 5 ÷ 2 = 2.5 mg/mL
• A 200 mcg dose = 0.2 ÷ 2.5 = 0.08 mL = 8 units
• Doses in the vial: 25

CJC-1295 no DAC — 2 mg vial, 2 mL of water

• Concentration: 2 ÷ 2 = 1 mg/mL
• A 100 mcg dose = 0.1 ÷ 1 = 0.1 mL = 10 units
• Doses in the vial: 20

CJC-1295 with DAC — 2 mg vial, 2 mL of water

• Concentration: 2 ÷ 2 = 1 mg/mL
• A 1000 mcg dose = 1 ÷ 1 = 1.0 mL = 100 units
• Doses in the vial: 2

Identical vial, identical water, and the draw goes from 10 units to the entire barrel of a 1 mL syringe. If you mixed a DAC vial expecting no-DAC numbers, the tell is immediate: the correct dose does not fit the syringe you reached for, and the vial holds two doses instead of twenty. That mismatch is the safety signal — the calculator surfaces both the draw size and the doses-per-vial for exactly this reason.

The half-life difference is not only about convenience

The two forms are easy to read as the same thing at different frequencies. They are not: they produce different exposure profiles, and this is one of the few places in this space where published human data describes the difference rather than protocol convention asserting it.

Growth hormone is normally secreted in pulses rather than held at a steady level. A short-acting GHRH analogue raises a pulse and then clears; a DAC-bound one keeps levels elevated across days. Whether the pulsatile pattern persists under that continuous stimulation is precisely what the published CJC-1295 work set out to measure, and that is the substantive difference between the two. Neither form has an established human dose or schedule, so the useful conclusion is that they are not interchangeable — not that either is the one to pick.

What to record

Log the DAC status in the entry itself, not just in your memory of which vial is which. “CJC 100 mcg” is ambiguous the moment you own both. “CJC no-DAC 100 mcg — 10 u at 1 mg/mL, vial opened 3 Aug” is not.

When two compounds are being run together, log them as two entries rather than one combined line. A single “CJC + Ipa” entry cannot record that one of them was skipped, which is exactly the thing you will want to know when interpreting a run later. Half-lives, vial sizes and storage for both forms are listed side by side in the library.