CJC-1295 vs CJC-1295 with DAC: 280 Daltons, and All the Human Data on One Side

Two products share one name and differ by 280 daltons. The trade-off this page resolves is evidence against convenience: the with-DAC form carries every human number and a weekly schedule, the without-DAC form carries none and a daily one.

Getting them the wrong way round is not a nuance — it is a dosing error by a factor of seven. Both sit in the growth hormone peptides category, with the evidence audit in CJC-1295 without DAC (Mod GRF 1-29): the molecule with no human trial of its own, the long-acting form in CJC-1295 with DAC: long-acting GHRH science, and the vial-level checks in where to buy CJC-1295: 7 purity and identity checks.

What does the DAC linker actually do?

The DAC linker is a thirtieth lysine bearing a maleimidopropionyl group that binds covalently to circulating albumin. That single addition is the entire difference between the two products. It extends half-life from about 30 minutes to 5.8–8.1 days, adds roughly 280 daltons — 3,367.9 g/mol becomes 3,647.2 — and moves dosing from daily to weekly. The 29-residue backbone underneath is identical in both.

The substitutions on the shared backbone are older than the linker and do a different job. D-Ala2, Gln8, Ala15 and Leu27 exist to resist enzymatic degradation, principally by dipeptidyl peptidase-IV, which clears native GHRH within minutes. That framework came from Campbell et al., "Enhanced stability and potency of novel growth hormone-releasing factor (GRF) analogues" (Peptides, 1994). ConjuChem Biotechnologies in Montreal then added the albumin linker on top of it and published the characterisation in Endocrinology, 2005, identifying CJC-1295 as a long-lasting GRF analogue — the DAC form.

So the naming is backwards from the history. "CJC-1295" was the name given to the albumin-binding molecule. The product sold as plain "CJC-1295" in most of this market is the backbone without it, whose unambiguous names are Mod GRF 1-29 and Modified GRF (1-29).

Same backbone, radically different pharmacokinetics — and, as the next section shows, radically different amounts of evidence.

Which of the two forms has the human data?

The DAC form has all of it. No published human study of the no-DAC form exists. Every figure that travels with the CJC-1295 name was measured with the albumin-binding molecule: the 2- to 10-fold GH elevation, the 1.5- to 3-fold IGF-1 rise, the 5.8–8.1 day half-life. The no-DAC form's magnitude, duration, optimal dose and safety profile in people have never been measured and published.

The n column is blank on purpose. Our fact bases do not carry participant counts for the two 2006 papers, and this page is not going to invent them.

That is a strong claim about the no-DAC form, so it is worth being precise about what it does and does not mean. It does not mean CJC-1295 without DAC has no effect. It is a GHRH receptor agonist, GHRH agonism is well characterised, and the mechanistic case that it raises GH in people is close to certain. It means nobody has measured how much, for how long, at what dose, or with what safety profile in a human being, and published it.

The Ionescu and Frohman finding is the strongest argument the GHRH-analogue approach has, and it is the one most often misattributed. Under continuous stimulation, the compound augments the body's own GH pulses rather than flattening them into a continuous exogenous signal, which is what recombinant hGH does. That is genuinely important endocrinology. It was also measured with a molecule whose half-life is days, and it is quoted constantly as though it were a property of a vial dosed twice a day.

How does the dosing schedule differ, and what happens if you get it wrong?

The no-DAC form is dosed daily or twice daily on a roughly 30-minute half-life; the DAC form is dosed weekly on a 5.8–8.1 day half-life. Get the two confused and the schedule is wrong by a factor of seven in one direction or the other. Community practice for the no-DAC form runs to 100–200 mcg daily subcutaneously, often split morning and evening, and no human trial has validated any no-DAC regimen at all.

The reasoning behind twice-daily no-DAC dosing is coherent: a 30-minute half-life calls for frequent administration to mimic natural GHRH pulses. Coherent is not the same as evidenced. Nobody has measured where the response curve flattens in humans for this molecule, which means the widely quoted saturation figure is a convention rather than a finding, and the distinction matters more here than for most compounds because there is no measured curve anywhere to fall back on.

Reconstitution arithmetic is the one part of this that is deterministic rather than inferred. Use the CJC-1295 and ipamorelin calculator for per-injection volume alongside the reconstitution calculator, and see how to calculate peptide doses if you are converting between vial strengths.

On the pairing everyone asks about: the receptor rationale for adding a ghrelin-receptor agonist is sound, because GHRH-R and GHS-R1a are separate receptors on the same pituitary somatotrophs, and stimulating both is expected to release more GH than either alone. No controlled human trial has quantified that combination for this GHRH form, so any specific synergy percentage you are shown is unsourced. See ipamorelin: the selective secretagogue that failed its only published human trial, the CJC-1295 and ipamorelin stack guide and the CJC-1295 and ipamorelin blend page.

Which molecular weight should a no-DAC listing print?

3,367.9 g/mol, with the formula C₁₅₂H₂₅₂N₄₄O₄₂. A no-DAC listing showing 3,645.9 or ~3,647 has copied a DAC-form figure, and that is a specification error rather than a rounding error. It is also common enough that our own compound page currently carries it: the CJC-1295 without DAC compound page shows a molecular weight of 3,645.9 — roughly 280 daltons above this molecule's actual mass.

That page is being corrected. Until it is, use the value in the identity table above rather than the one on the page. We are naming it in the body of the article rather than in a footnote because a buyer checking a vendor's spec sheet against ours would currently be checking it against the wrong number, and the same standard has to apply to us as to a seller.

The error has a diagnostic use once you know about it. The 3,645.9 figure is exactly the mistake the naming collapse produces: a page describing the short-acting form while carrying the long-acting form's specification, usually because the specification was copied from a chemical database rather than checked. Querying "CJC-1295" in chemical databases returns the DAC form at 3,647.2, so a vendor selling "CJC-1295" at 3,367.9 is selling Mod GRF (1-29) under a name that belongs to a different molecule — and a vendor selling "CJC-1295 without DAC" at 3,645.9 has done the opposite.

A related database caution closes this out. PubChem's records for CJC-1295 carry conflated synonyms, with both DAC and no-DAC names attached to the same structure; the record has had "CJC1295 With DAC" and "CJC1295 Without DAC" listed as synonyms and subsequently removed them. Treat that record as the DAC form only, and verify against the mass and the structure rather than trusting a name in a synonym list. A vendor screenshotting a database entry has not confirmed anything. See mass spectrometry for peptides and red flags in peptide certificates of analysis.

Where does sermorelin sit between the two forms?

Sermorelin sits 10 daltons below the no-DAC form at 3,357.9 against 3,367.9, and it is by far the harder discrimination of the two on this page. The 280-dalton DAC gap is resolved by any mass spectrometer; a 10-dalton gap is not settled by a rounded nominal mass on a low-resolution instrument. Sermorelin is also the only member of this family FDA ever approved — twice, in 1990 and 1997 — and the only one absent from FDA's Category 2 list.

The substitution that produces the 10-dalton gap does something more useful than change the mass. Met27→Leu27 removes the molecule's only sulfur atom, so the two differ in elemental composition as well: C₁₄₉H₂₄₆N₄₄O₄₂S against C₁₅₂H₂₅₂N₄₄O₄₂. Ten daltons is nothing to a purity certificate and everything to a mass spectrometer, and sulfur present versus sulfur absent is a binary that a composition report answers outright. That is why the useful request here is a high-resolution result reporting elemental composition rather than a single rounded number.

The regulatory contrast between the three is sharper than the chemical one. Sermorelin qualifies for 503A compounding as a component of a previously FDA-approved drug, and it appears nowhere on FDA's Category 2 list of bulk substances that may present significant safety risks. Both CJC-1295 forms were reviewed and rejected. Ten daltons of chemistry separate two molecules on opposite sides of a compounding pathway. Sermorelin's own evidence and approval history — including an adult trial that found nothing downstream of the GH curve — is in sermorelin: the only GH peptide FDA ever approved.

Why did CJC-1295 development stop?

The Phase 2 programme was halted in July 2006 after a participant died. NCT00267527, a trial of CJC-1295 in HIV-associated visceral obesity, is recorded as terminated; it was stopped after a participant died of a myocardial infarction hours after receiving an eleventh weekly dose. The attending physician attributed the event to pre-existing asymptomatic coronary artery disease rather than the study drug. ConjuChem ended the programme, and no sponsor has pursued registration in the twenty years since.

That attribution may well be correct. The participant had undiagnosed heart disease, and single events in small trials rarely establish causation. This page is not asserting that the compound killed anyone.

What is verifiable is the shape of the record. Anyone evaluating either form should know that its trial history ends with a death and an abandoned programme, whatever the causal verdict, and that this is the reason there is no Phase 3, no label and no long-term human safety dataset for either version. The eleventh weekly dose detail also locates the event in the DAC form's dosing schedule, which is the only one either form has ever been given on in a registered trial.

Twenty years on, that remains the terminal point of CJC-1295's clinical development — and it is why the no-DAC form's evidence gap is structural rather than temporary. There is no ongoing programme that will close it.

Is either form legal to compound?

Neither. FDA placed CJC-1295 in 503A Category 2 in September 2023, removed it in September 2024 after the nominators withdrew and referred it for advisory review, and at the Pharmacy Compounding Advisory Committee meeting of 4 December 2024 proposed that all five CJC-1295 substances be excluded from the 503A bulks list. The committee agreed. CJC-1295 is not approved by the FDA, EMA or TGA, and both forms are prohibited in sport at all times under WADA S2.2.4.

The five substances are the free base, the acetate, the DAC free base, the DAC acetate and the DAC trifluoroacetate — every form on the market, including both of the ones this page compares. That is why the salt form belongs on a verification checklist alongside the DAC status: they are five distinct regulatory objects sharing one commercial name.

The direction of travel runs opposite to the rest of this category, and sellers exploit the confusion. CJC-1295 was not on the July 2026 PCAC agenda, so the December 2024 outcome stands. BPC-157, KPV, TB-500 and MOTS-c were recommended for the bulks list in July 2026; CJC-1295 was reviewed earlier and rejected. "Peptides are being reconsidered by FDA" is true in general and false for this one — a distinction worth keeping straight when a seller cites the July 2026 news to imply a change here. Our FDA peptide regulation timeline tracks where each nomination actually stands, and compounding pharmacy versus research peptide sets out what each route carries.

On sport, both forms are named at S2.2.4, Growth Hormone Releasing Factors, which lists GHRH analogues explicitly alongside CJC-1293, sermorelin and tesamorelin. That is a named-category prohibition, not an inference from a catch-all clause, and it applies at all times, in and out of competition, to both forms equally.

Which is harder to verify, and what does each cost?

Neither is hard to tell apart — mass spectrometry resolves 280 daltons trivially — and that is precisely why the failure here is a labelling failure rather than an analytical one. The Purity Index records the no-DAC form at 99.53 and the DAC form at 99.23 (verified August 2026), against a platform composite of 99.50. A purity figure reports what proportion of a sample is one species, not which species, so both numbers are entirely compatible with receiving the wrong form in excellent condition.

Two of those checks cost nothing and can be run before any purchase, by reading the product page. On a compound whose central failure is a naming collapse rather than a manufacturing defect, that is where most of the available protection actually sits.

On cost, we are naming a gap rather than filling it. CJC-1295 without DAC price data publishes shops in stock, median and lowest price per milligram with the vial size behind the lowest figure, and is the current source for cost comparisons. Our fact base does not carry a specific median or low for either form, so this page does not print one. Read the live page within a single vial-size band, since fixed per-vial costs push the per-milligram figure down as fill size rises. Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing.

One pricing principle is specific to this comparison and survives the missing numbers. A per-milligram comparison between the two forms is not a like-for-like cost comparison, because the DAC form is dosed weekly and the no-DAC form daily or twice daily. The same milligram buys a very different number of administrations, so the cheaper per-milligram product is not necessarily the cheaper course. The cost-per-dose calculator converts one into the other once you have fixed a schedule.

Peptigrity tracks 530 shops and 11,852 independent lab tests across 118 peptides, with 1,283 community reviews (verified August 2026), weighting community reviews and independently verified purity equally at 50% each in every trust score, with no financial relationship influencing the ranking. Individual results are searchable in the lab test database, and the method reading is how to read peptide lab test results and why 10 mg isn't 10 mg.

So which should you choose?

On evidence, the DAC form wins by default — it is the only one of the two with any published human data, and every number quoted for either belongs to it. On identity risk, the two are equally verifiable and the risk is in the labelling, not the chemistry. On the question most buyers actually mean — which produces a better result — neither has an answer, because no controlled human trial has compared them and the no-DAC form has never been studied in people at all.

If you use either form anyway, the monitoring convention is worth stating with its limits attached. Community practice is IGF-1 measured against an age-adjusted reference range every six to eight weeks. That is community-derived, not clinical guidance, and the reference range is strongly age-dependent — so a flat cutoff like "stop above 250 ng/mL" is not meaningful, because that value can be entirely normal in a young adult and clearly elevated in someone in their sixties. Stop if joint pain or swelling appears, if headaches or vision changes occur without another explanation, or if IGF-1 stays persistently elevated. Anyone with a history of cancer, diabetes or impaired glucose tolerance should not be self-experimenting with the GH axis at all: GH elevation reduces insulin sensitivity, and the IGF-1 axis is implicated in tumour growth.

The trial that would settle this

The missing study is unusually simple to specify: a randomised, placebo-controlled trial of the no-DAC molecule itself, dosed subcutaneously the way people dose it, with GH and IGF-1 measured across a dose range and body composition as a secondary endpoint. Every property this form is sold on — magnitude, duration, saturation point, body-composition effect — currently comes from the DAC form or from GH physiology. One dose-ranging study would replace all of it with measurement.

Frequently Asked Questions

What is the actual difference between the two forms?

One addition: a thirtieth lysine carrying a maleimidopropionyl group that binds covalently to albumin. That extends the half-life from about 30 minutes to 5.8 to 8.1 days and adds roughly 280 daltons of mass, taking 3,367.9 g/mol to 3,647.2. The 29-residue backbone, with its four substitutions and C-terminal amide, is otherwise identical.

Is there any human trial of CJC-1295 without DAC?

No. The published human data — Teichman 2006 and Ionescu and Frohman 2006, both in JCEM — used the DAC form. The no-DAC molecule has never been through a published human study, so its magnitude, duration and safety in people are inferred rather than measured. Its 30-minute half-life is consistent with the absence of albumin binding rather than derived from a human pharmacokinetic paper.

How do I know which form is in my vial?

Mass spectrometry. Roughly 3,368 daltons is the no-DAC form and roughly 3,647 is the DAC form, a gap any instrument resolves. Vendors frequently sell both under the unqualified name "CJC-1295," an HPLC purity figure cannot tell them apart, and PubChem's synonym lists conflate them — so verify against the mass and the structure, not the name.

Why does the molecular weight on some listings say 3,645.9?

Because it was copied from a DAC-form specification. The correct value for the no-DAC form is 3,367.9 g/mol with the formula C₁₅₂H₂₅₂N₄₄O₄₂. Our own CJC-1295 without DAC compound page currently carries the 3,645.9 figure and is being corrected; the same standard applies to any vendor page showing it.

Is either form legal to compound?

No. FDA proposed in December 2024 that all five CJC-1295 substances — free base, acetate, DAC free base, DAC acetate and DAC trifluoroacetate — not be included on the 503A bulks list, and the advisory committee agreed. It was not revisited in July 2026. Both forms are also prohibited in sport at all times under WADA S2.2.4.

How close is sermorelin to the no-DAC form?

Ten daltons — 3,357.9 against 3,367.9 — which is closer than any other discrimination in this family and too close for a rounded nominal mass. The Met27→Leu27 substitution that produces the gap also removes sermorelin's only sulfur atom, so elemental composition settles it where a mass number alone does not. Sermorelin is the only member of this family FDA ever approved.

Where the two forms leave a buyer

The two products are separated by one linker, 280 daltons, a sevenfold difference in dosing frequency, and the entire human evidence base. Only the last of those is asymmetric in a way that matters, and it runs the opposite way to the market: the form most people buy is the form nobody has studied, and every number printed beside it on a vendor page was measured with the other one.

The identity problem is the easiest to fix and the most consistently unfixed. Two hundred and eighty daltons is trivial for a mass spectrometer, so a vial's DAC status is answerable for the cost of one identity result — and it goes unanswered because the failure is a naming collapse rather than an analytical limit. Vendors sell both under an unqualified name, chemical databases return the DAC form when you query the shared one, and our own compound page currently prints the wrong mass.

That leaves a position narrower than "avoid it" and wider than "it's fine". You are buying a molecule whose identity you can verify to the dalton and whose effects you cannot verify at all, from a family whose clinical programme ended in 2006 with a death and an abandonment, and whose entire set of forms FDA's advisory committee declined in December 2024. Those facts deserve different weights in the decision, and usually do not get them.

Browse the growth hormone peptides category, or our complete peptide guide with 118 compounds (verified August 2026). For per-injection volume, use the CJC-1295 and ipamorelin calculator alongside the reconstitution calculator. Compare shops through independent lab tests and community-verified shop reviews.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.