CJC-1295 with DAC: How the Long-Acting Form Works

What DAC does to CJC-1295

CJC-1295 with DAC (Drug Affinity Complex) is a modified form of CJC-1295 that binds covalently to albumin — the most abundant protein in blood plasma — after injection. Albumin has a half-life of approximately 19 days. By binding to it, CJC-1295 with DAC dramatically extends its own half-life from ~30 minutes (the no-DAC form) to approximately 6–8 days.

The DAC technology was developed by ConjuChem specifically to overcome the short half-life of native GHRH(1-29). The result is a compound that needs to be injected only once or twice a week to maintain elevated GH secretagogue activity across multiple days.

Pulsatile vs. sustained GH release

The key pharmacodynamic difference between DAC and no-DAC forms is not just duration — it is the pattern of GH release:

• CJC-1295 no DAC (Mod GRF 1-29): Short duration → produces a discrete GH pulse lasting 1–2 hours post-injection, then clears. When dosed daily with Ipamorelin, you get one amplified GH pulse per day — mimicking (and amplifying) the natural pulsatile rhythm.
• CJC-1295 with DAC: Long duration → produces sustained GHRH receptor stimulation across 6–8 days. This tends to blunt the pulsatile GH pattern because the pituitary is continuously stimulated rather than receiving discrete signals. Average GH exposure over days is higher, but the peak-to-trough pulsatility that characterizes natural GH secretion is reduced.

This distinction matters because physiological GH secretion is pulsatile — the liver primarily responds to GH pulses for IGF-1 production, and many of GH's anabolic effects depend on the pulse pattern. Whether sustained vs. pulsatile GH elevation is better for a given goal is a clinical judgment that remains debated in the literature.

Why CJC-1295 with DAC is usually not paired with Ipamorelin

The standard CJC-1295/Ipamorelin protocol uses the no-DAC form. The logic: Ipamorelin has a ~2-hour half-life. If you're dosing Ipamorelin once or twice daily for discrete GH pulses, the ideal CJC-1295 partner has a similarly short window — amplifying the same pulse, then clearing.

CJC-1295 with DAC doesn't match that timing: it provides continuous GHRH receptor stimulation regardless of when you inject Ipamorelin, removing the discrete pulse structure that justifies the combination.

CJC-1295 with DAC is typically used as a standalone compound (without Ipamorelin) for users prioritizing sustained IGF-1 elevation over pulsatile GH patterns — or by practitioners who prefer less frequent injections. Some protocols use DAC once weekly as a "GH axis primer" and do not add Ipamorelin.

IGF-1 elevation: the published data

The Ionescu and Frohman 2006 study is the key published reference. In healthy adults, a single injection of CJC-1295 with DAC produced:

• GH levels elevated 2–10× above baseline for 6 days post-injection
• IGF-1 levels elevated 1.5–3× above baseline, sustained across the week
• Dose-dependent response: higher doses produced greater and longer elevation

These figures are from healthy adult subjects, not from patient populations with GH deficiency. They establish that the DAC mechanism produces meaningful, sustained GH axis stimulation from a single weekly dose.

Reconstitution and dosing

CJC-1295 with DAC vials are typically 2 mg. Standard research protocols have used 1–2 mg once or twice weekly. Reconstitution math:

Use the CJC-1295 calculator for your specific vial and dose setup.

Fasted-state timing with DAC

The fasted-state requirement that applies strictly to no-DAC protocols (inject when insulin is lowest to maximize GH pulse amplitude) is less operationally critical for CJC-1295 with DAC. Because DAC provides continuous GHRH receptor stimulation across days, the single injection timing matters less for individual pulse amplitude. That said, injecting when fasted is still generally preferred as a standard practice for GH secretagogues.

Which form is right for your protocol?

Your prescription and your provider's protocol design determine which form you're using. If your vial just says "CJC-1295," confirm with your compounding pharmacy whether it includes DAC — the two forms have substantially different dosing schedules and pharmacodynamics. A twice-daily protocol is designed for no-DAC; an once-weekly protocol is designed for DAC. Using a DAC vial on a daily protocol (or no-DAC vial on a weekly protocol) would be a significant mismatch.