CJC-1295 With DAC vs No DAC: One Chemical Group, Two Completely Different Compounds
The most commonly mis-ordered peptide in Canada is CJC-1295, because two products share the name and differ by a single modification that changes the half-life from minutes to days. Here is how to tell them apart before you order the wrong one.
- CJC-1295 exists in two forms: with DAC (Drug Affinity Complex) and without. They share a name and almost nothing else functionally.
- CJC-1295 no-DAC is Modified GRF 1-29 — a short-acting GHRH analogue with a half-life measured in minutes, producing a pulsatile signal.
- CJC-1295 with DAC carries a maleimidoproprionic acid group that binds serum albumin, extending the half-life to days and producing sustained elevation instead of pulses.
- Pulsatile versus sustained is a genuine mechanistic difference, not a dosing convenience — GH secretion is naturally pulsatile, and which pattern you produce is often the research question itself.
- The product supplied here is CJC-1295 no-DAC (Mod GRF 1-29), stated explicitly rather than left ambiguous.
- For in vitro laboratory research use only — not for human or veterinary consumption.
Same name, different molecule
If there is one ordering error we see more than any other, it is this one. Two products circulate under the name CJC-1295. They differ by a single chemical modification. That modification changes the half-life from **minutes to days**.
The compound supplied here is CJC-1295 no-DAC, also written Modified GRF 1-29 — and we say so on the product page rather than leaving you to work it out.
What DAC actually is
Both versions are analogues of growth-hormone-releasing hormone, based on the first 29 amino acids of GHRH — the fragment that carries the receptor activity.
**CJC-1295 no-DAC (Mod GRF 1-29)** is that fragment with stabilising substitutions to resist enzymatic degradation. Its half-life is on the order of **minutes**. It produces a brief, sharp signal at the GHRH receptor and then clears.
**CJC-1295 with DAC** takes the same peptide and attaches a **maleimidoproprionic acid group** — the Drug Affinity Complex. That group binds covalently to serum albumin, and because albumin circulates for a long time, the peptide circulates with it. Half-life goes from minutes to **days**.
One added chemical group. Three orders of magnitude of difference in duration.
Why the difference is mechanistic, not just convenient
It is tempting to read the DAC version as "the same thing, less frequently." That misreads the biology.
**Endogenous GH secretion is pulsatile.** The body releases it in discrete bursts, largely during sleep, and the pulsatility is not incidental — downstream signalling responds differently to a pulse than to a plateau.
- —**No-DAC produces pulses.** A short signal that rises and clears, closer to the natural pattern.
- —**With DAC produces sustained elevation.** A continuous signal rather than discrete bursts.
For a research question about pulsatile signalling, receptor dynamics, or anything approximating physiological GHRH behaviour, the short-acting version is the correct instrument and the long-acting one will actively obscure what you are looking at. For questions about sustained receptor occupancy, the reverse holds.
This is also why CJC-1295 no-DAC is so often paired with ipamorelin: the GHRH analogue and the ghrelin-receptor secretagogue act on separate pathways, and the short-acting version keeps the combined signal pulsatile. Tesamorelin, another GHRH analogue, sits nearby in the same family — molecular data for all of them is in our reference library, with side-by-side breakdowns on our comparison pages.
How to avoid ordering the wrong one anywhere
A checklist that works regardless of who you buy from:
1. **Does the listing state DAC status explicitly?** If a product is sold as plain "CJC-1295" with no clarification, that ambiguity is the seller's choice, and you are the one who absorbs it.
2. **Does it name Mod GRF 1-29?** That name only applies to the no-DAC form. Its presence is a good sign.
3. **Does the stated half-life match?** Minutes means no-DAC. Days means DAC. If the page says neither, ask before ordering.
4. **Is there a batch certificate of analysis?** LC-MS confirms molecular identity — which is ultimately the only way to know which molecule you actually received.
On the last point: every batch we sell is tested by an **independent third-party laboratory**, HPLC for purity and LC-MS for identity, with published-batch purity averaging above 99%. Enter your lot number and read the certificate for your exact vial, or review all published results before ordering anything.
And it ships from **Vancouver, BC** — typically 2 to 5 business days, tracked, insured, discreetly packaged, Canadian dollars, free shipping over $300 CAD. Nothing crosses a border, so nothing is held at one. Most research compounds bought in Canada arrive from overseas and take that risk every time.
Frequently asked questions
What is the difference between CJC-1295 with DAC and without DAC?
The DAC version carries a maleimidoproprionic acid group that binds serum albumin, extending the half-life from minutes to days. The no-DAC version, also called Mod GRF 1-29, is short-acting and produces a pulsatile signal rather than sustained elevation.
What is Mod GRF 1-29?
Mod GRF 1-29 is another name for CJC-1295 without DAC — a modified fragment of the first 29 amino acids of growth-hormone-releasing hormone, stabilised against enzymatic degradation but without the albumin-binding group.
Which version does Popular Peptides sell?
CJC-1295 no-DAC (Mod GRF 1-29), the short-acting form. It is stated explicitly on the product page rather than left ambiguous.
Why does pulsatile versus sustained signalling matter?
Endogenous growth hormone secretion is naturally pulsatile, and downstream signalling responds differently to discrete pulses than to continuous elevation. Which pattern a compound produces is frequently the research question itself, not a scheduling detail.
Where can I buy CJC-1295 no-DAC in Canada?
Popular Peptides supplies CJC-1295 no-DAC for laboratory research use, shipped domestically from Vancouver, BC with a third-party certificate of analysis verifiable by lot number. It is not sold for human or veterinary consumption.
CJC-1295 (No DAC) is supplied for in vitro laboratory research use only. It is not approved by Health Canada for therapeutic use and is not intended for human or veterinary consumption. 18+.
Every batch we sell is independently third-party tested, with the full Certificate of Analysis published and checkable by lot number.