CJC-1295 Without DAC in Canada: How It Differs From the DAC Form
Purchase orders for this compound are easy to get wrong, and the cause is usually the name. Before you order CJC-1295 without DAC in Canada, or the DAC-modified form from anyone, it helps to know that the catalogue names cover two chemically distinct molecules. One carries an albumin-binding linker and one does not, and a mass spectrum tells them apart in seconds. This guide is written for the people who specify, receive and release the material: what separates the two forms, what the sequence changes are for, and what to check when a multi-vial shipment lands on your bench.
Three catalogue names, two molecules
Suppliers and papers use a handful of labels interchangeably, which is where the confusion starts. Sorted by chemistry, they collapse into two groups:
- Unmodified tetrasubstituted GRF(1-29): sold as CJC-1295 without DAC, CJC-1295 no DAC, or Modified GRF (1-29), usually shortened to Mod GRF 1-29.
- The DAC conjugate: the same 29-residue backbone plus an extra lysine carrying a reactive linker, sold as CJC-1295 with DAC or sometimes simply CJC-1295.
That last habit is the trap. A listing that says only “CJC-1295” could mean either one, so a procurement lead should never accept the bare name on a quote. Ask for the sequence and the calculated molecular mass, and write both into the order.
It is also worth separating both from sermorelin, which is the native GRF(1-29) amide with none of the substitutions described below. Three products, three different masses.
What the DAC linker does, chemically
DAC is short for Drug Affinity Complex. In the conjugate, a lysine is appended after position 29 and a maleimidopropionyl group is attached to that lysine’s side chain. Maleimides react readily with free thiols, and serum albumin has one unpaired cysteine (Cys34) exposed on its surface. The maleimide couples to it and forms a stable thioether bond, tethering the peptide to a large carrier protein. In the published literature, that tether is the reason the conjugate persists far longer in albumin-containing systems than the free peptide does.
For a QC lab, the practical points are different from the pharmacological ones:
- The conjugate is heavier than Mod GRF 1-29 by the added lysine plus the linker, so identity by mass is unambiguous.
- The maleimide is deliberately reactive. It can couple to thiols in your own buffers or additives, so avoid thiol-containing reagents when handling analytical samples of the DAC form.
- Maleimide rings can hydrolyse in aqueous solution, producing a ring-opened species 18 Da heavier. On an LC-MS trace of the DAC form, a +18 companion peak is worth recognising rather than mistaking for a contaminant.
None of those concerns apply to the unmodified peptide, which has no linker to react or hydrolyse.
The four substitutions and why a QC lab should care
The bracketed notation you will see on a certificate, [D-Ala2, Gln8, Ala15, Leu27]-GRF(1-29)-NH2, records four deliberate departures from the native sequence. Each one was chosen to remove a known weak point, and several of them change what you should expect in your own stability and purity data.
| Position | Native residue | Replaced with | Reason in the analog literature |
|---|---|---|---|
| 2 | L-Alanine | D-Alanine | Native GRF is clipped between residues 2 and 3 by dipeptidyl peptidase-4; the D-isomer resists that enzyme. |
| 8 | Asparagine | Glutamine | Asparagine is prone to deamidation; glutamine deamidates far more slowly. |
| 15 | Glycine | Alanine | Reported to improve activity at the GHRH receptor, consistent with a more stable helix. |
| 27 | Methionine | Leucine | Removes a residue that readily oxidises to the sulfoxide. |
Two of those rows matter directly for release testing. With no methionine, the familiar +16 Da oxidation variant that haunts native GRF samples should not appear at position 27. With glutamine at position 8, the +1 Da deamidation products that tend to form in stored native material should be much less prominent. If you do see them building up across a long-held lot, look at storage conditions before blaming the synthesis.
The C-terminal amide is the final detail. Replacing the free acid with an amide lowers the mass by just under one dalton, so the calculated mass on a certificate should reflect the amidated form. For Mod GRF 1-29 that is C152H252N44O42 at 3367.9 g/mol.
Checking CJC-1295 without DAC in Canada on arrival
When a bulk order arrives, the receiving check can be short if the paperwork is right. A workable routine for a multi-vial shipment:
- Confirm the label reads “without DAC” or “Mod GRF 1-29”, not the bare name.
- Compare the formula and mass on the certificate with 3367.9 g/mol. A figure a few hundred daltons higher points to the DAC conjugate, whatever the label says.
- Match the vial’s cap and crimp colour to the certificate you are filing against, and record that pairing in your inventory log.
- Count vials by lot and note the arrival condition of the lyophilised cake and the packaging temperature.
- Move the stock to cold, dark storage the same day and log the date the vials went in.
For labs that pull from the same order over months, step three is the one that saves time later. A log entry tying each vial group to its certificate lets you trace any unexpected result back to a specific lot without re-testing the whole shelf.
When it arrives blended with Ipamorelin
Mod GRF 1-29 is frequently supplied in a single vial with Ipamorelin, a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2, CAS 170851-70-4) with a mass of about 712 g/mol. The two share almost nothing structurally: one is a 29-residue helix-forming chain, the other a short, heavily non-natural sequence roughly a fifth of its size.
That makes a blend easy to assess. On reversed-phase HPLC the two components separate cleanly, so an honest chromatogram shows two distinct main peaks, each with its own area. A blend report that gives one peak and one purity number has not told you how pure either component is. Ask for the per-component figures, and confirm both masses by MS. Our CJC-1295 and Ipamorelin blend and the single-compound Ipamorelin vial are listed separately for labs that want to assess each on its own.
Writing the spec for a volume order
If your lab buys in quantity, put the identity requirements in writing so that any future reorder is checked against the same standard. A short spec line covers most of it: compound name with the DAC status stated, full sequence notation including the amide, molecular formula, calculated mass, and the minimum HPLC purity you will accept. Asking for everything in one lot where possible keeps the whole order under a single certificate and removes lot-to-lot variation from your data.
Bulk Peptides stocks the unmodified form only, listed as CJC-1295 without DAC. We do not carry the DAC conjugate. Vial pricing is mix-and-match, so every vial in the cart counts toward the volume break, whether it is this compound or others in the growth hormone secretagogue range. Orders ship from within Canada, so there is no customs hold between our shelf and your cold room.
Certificates and third-party testing
Our products are third-party tested for purity by HPLC. Certificates are published for some products, either on the product page or on the certificates of analysis page, and vials are matched to their certificate by cap and crimp colour. If the certificate for your lot is not posted, contact us and we will send what we have on file for it. Keep in mind what the standard tests cover: HPLC measures purity and MS confirms identity, but neither addresses sterility, endotoxin or residual solvents unless the report lists those assays. If an independent lab reaches a different result, the purity guarantee page explains what we do about it.
Every compound discussed in this article is sold by Bulk Peptides strictly for in-vitro laboratory research. It is not intended for human or animal use, is not approved by Health Canada as a drug or health product, and nothing here should be read as guidance on use.
