CJC-1295 with DAC dosing — study doses vs the commonly reported pattern

Research doses were weight-based; the circulating community figure is not. Across the three published human studies, 63 healthy adults received doses of 30–250 mcg/kg subcutaneously, and 73% of them received a single injection (FDA briefing document, PCAC December 2024). The terminated phase 2 trial used once-weekly injections escalating through 60, 90 and 120 mcg/kg in its low-dose arm and 60, 120 and 240 mcg/kg in its high-dose arm. Research and community sources instead describe a flat 1–2 mg once weekly — which, for a 70 kg adult, works out at roughly 14–29 mcg/kg, at or below the bottom of the studied range.

• Four ascending single subcutaneous doses in the first randomized, placebo-controlled study, followed by two or three weekly or biweekly doses in the second, over 28 and 49 days respectively, in healthy adults aged 21–61 (Teichman et al., J Clin Endocrinol Metab 2006). Adverse effects — injection-site reactions, diarrhoea, flushing — were clearly dose-related, and were most frequent at 125 and 250 mcg/kg.

• 60–240 mcg/kg once weekly for 12 weeks in the ConjuChem phase 2 study in HIV-associated visceral obesity, which was terminated in 2006 and never published (NCT00267527).

Note what does not exist: any dose-finding study, any study in people with growth hormone deficiency, and any published exposure beyond a few months.

A weight-based dose and a flat dose diverge most for the people furthest from average. A flat 2 mg is about 33 mcg/kg for a 60 kg person and about 20 mcg/kg for a 100 kg person — a 1.6-fold difference in exposure between two people following the same "protocol." The studies that generated the pharmacokinetic data did not test flat dosing, so there is no published basis for predicting what either person's GH response would be.

There is a second, sharper problem: nobody can be sure which substance is in the vial. FDA identified five distinct CJC-1295-related bulk substances (free base, acetate, DAC free base, DAC acetate, DAC trifluoroacetate) and concluded that even in the published studies "it is unclear which substance was used," with no salt form specified. Products sold as CJC-1295 have historically included preparations without any DAC at all (Henninge et al., Drug Test Anal 2010) — a compound with a half-life of minutes, not days, being dosed on a weekly schedule designed for the long-acting form.

The weekly interval is not arbitrary. The estimated half-life of CJC-1295 with DAC in healthy adults is 5.8–8.1 days, because the peptide's maleimido-lysine group bonds covalently to cysteine-34 on serum albumin and then circulates with it (Teichman 2006; Jetté et al., Endocrinology 2005). A single injection raised GH for six days or more and IGF-1 for 9–11 days, and repeat dosing kept IGF-1 elevated for up to 28 days.

Two consequences follow directly. Weekly dosing produces overlapping exposure rather than discrete pulses, which is the source of the "GH bleed" objection — a sustained elevation departs from the body's normal pulsatile pattern, and the clinical significance of that difference has never been tested. And because the compound is present for over a week, an unwanted effect cannot be stopped by skipping the next dose.

Absent a label, two things go unchecked: what is in the vial, and whether raising GH is a bad idea for the person injecting it. On the first, FDA found the CJC-1295 substances "not well characterized," with inconsistent naming conventions and missing characterization data. Peptides are also sensitive to formulation and storage conditions that drive aggregation and degradation — the attributes that determine immunogenicity risk in an injected product.

On the second, the known risks of a sustained GH/IGF-1 elevation are the ones on approved growth hormone labels: neoplasm risk, glucose intolerance, fluid retention, intracranial hypertension. In December 2024 the Pharmacy Compounding Advisory Committee voted 13–0 against placing any form of CJC-1295 on the 503A bulks list (PCAC final summary minutes, 4 December 2024). Those are the questions a clinician can screen and monitor for, and a number on a forum cannot.

For the full safety picture see CJC-1295 with DAC side effects; for what the studies did and did not measure, see research and evidence.