CJC-1295: What the Evidence Says About This GHRH Analog

What Is CJC-1295?

CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone (GHRH) designed to overcome native GHRH’s extremely short half-life. It exists in two distinct forms (with and without a Drug Affinity Complex) that have substantially different pharmacokinetics.

CJC-1295 was developed by ConjuChem Biotechnologies (hence “CJC”) as an improved version of GHRH that could remain active in circulation long enough to be clinically useful. Native GHRH has a half-life of only 5–7 minutes, which limits its therapeutic potential. CJC-1295 was engineered to address this.

There are two variants that behave quite differently:

CJC-1295 with DAC (Drug Affinity Complex): Uses a maleimide-modified lysine residue to bind covalently to serum albumin after injection. This albumin binding extends the half-life to approximately 6–8 days, creating sustained GH elevation. This is the form that was studied in human clinical trials.

CJC-1295 without DAC (often called Mod GRF 1-29): A 29-amino acid peptide with four amino acid substitutions that improve resistance to enzymatic degradation, resulting in a half-life of approximately 30 minutes. This creates distinct GH pulses rather than sustained elevation.

The distinction between these two variants is not trivial. It affects dosing frequency, the pattern of GH elevation, and potentially the side effect profile.

Who this page is for, and who it isn’t for

This page is for people who want to understand the pharmacology, evidence base, and limitations of CJC-1295 as a GH secretagogue. It is written for researchers, clinicians, and informed readers.

This page is not a dosing manual, a purchasing recommendation, or medical advice. CJC-1295 is not FDA-approved for any human therapeutic use.

How CJC-1295 Is Thought to Work

CJC-1295 stimulates growth hormone release by activating the same receptor as the body’s own GHRH, but with greater stability in circulation.

GHRH receptor activation

CJC-1295 binds to the GHRH receptor (GHRH-R) on pituitary somatotroph cells, the same receptor targeted by the body’s endogenous GHRH. This is a G protein-coupled receptor that activates the cAMP/PKA signaling pathway:

1. GHRH-R activation stimulates adenylyl cyclase
2. Increased cAMP production follows
3. Protein kinase A (PKA) activation
4. GH gene transcription and GH vesicle release

This mechanism is fundamentally different from ghrelin-mimetic peptides like ipamorelin or GHRP-6, which act on the GHS-R1a receptor. The fact that these two pathways converge synergistically on pituitary cells is the pharmacological basis for combining GHRH analogs with ghrelin mimetics.

How DAC and no-DAC versions differ in practice

CJC-1295 with DAC binds to circulating albumin after injection, which dramatically slows its clearance. The result is sustained GHRH receptor stimulation over days, creating a pattern of elevated baseline GH rather than the distinct spikes that characterize natural GH secretion. This represents a trade-off: convenience (weekly dosing) versus physiological fidelity.

Because this version stays active in the body for roughly a week, its effects do not stop quickly and may linger for one to two weeks after the last dose.

CJC-1295 without DAC (Mod GRF 1-29) clears in roughly 30 minutes, producing an acute GH pulse that more closely resembles the body’s natural pulsatile GH release pattern. It requires more frequent injection (2–3 times daily) but preserves the pulsatile dynamics that some researchers consider important for downstream signaling.

The role of somatostatin

An important physiological detail: GHRH-pathway stimulation remains subject to somatostatin (GHIH) inhibition. Somatostatin is the hypothalamic hormone that suppresses GH release. This means CJC-1295’s effectiveness is influenced by somatostatin tone, which varies throughout the day, being lowest during sleep and fasting.

This is also why combining CJC-1295 with a ghrelin mimetic like ipamorelin or GHRP-2 is thought to be synergistic: ghrelin mimetics can partially overcome somatostatin’s inhibitory effect, amplifying the GHRH signal.

What the Research Shows

Human clinical data (CJC-1295 with DAC)

The most significant human data comes from a 2006 Phase I/II study. In healthy adults (n=33), a single subcutaneous injection of CJC-1295 with DAC produced:

• Mean GH levels increased 2- to 10-fold for 6+ days
• IGF-1 levels increased 1.5- to 3-fold for 9–11 days
• The response was dose-dependent (30, 60, 90 μg/kg)
• No serious adverse events in this trial

Multiple doses (weekly for 4 weeks) produced sustained IGF-1 elevation without tachyphylaxis, meaning the pituitary did not stop responding over the course of the study (Teichman et al., 2006).

This is meaningful data, but it comes from a small trial over a short period. Long-term efficacy and safety in larger populations have not been established.

Safety signal in clinical development

In 2006, a clinical trial of a CJC-1295-related compound (by a different company, using a different formulation) reported a serious adverse event: a patient death attributed to cardiac complications. This event significantly slowed clinical development of all CJC-1295 variants. The relationship between CJC-1295 itself and the adverse event was debated, but the incident understandably created regulatory caution.

Body composition observations

In the multi-dose phase of clinical work, CJC-1295 with DAC treatment was associated with increased lean body mass, decreased abdominal visceral fat, and improved nitrogen balance. These effects are consistent with expected GH/IGF-1 axis activation and parallel the body composition effects of exogenous GH therapy, though at potentially lower magnitude.

GH pulsatility studies (Mod GRF 1-29)

Studies on the parent compound (GRF 1-29) and its analogs show that bolus injection produces a GH pulse lasting 1–2 hours. When combined with a ghrelin mimetic, the GH pulse amplitude is significantly greater than either compound alone, confirming the synergistic pharmacology that underlies the common practice of pairing GHRH analogs with GH-releasing peptides.

How it compares to exogenous GH

CJC-1295, particularly with DAC, raises GH and IGF-1 to levels approaching low-dose exogenous GH therapy, but through endogenous production. Potential advantages include release of multiple GH isoforms (not just the 22kDa form), preserved negative feedback (especially with the no-DAC version), and no suppression of endogenous production.

Limitations compared to exogenous GH include a less precise dose-response relationship and effectiveness that is limited by pituitary capacity, which naturally declines with age.

What CJC-1295 Has Been Studied For (Summary)

Based on available research:

• GH and IGF-1 elevation: demonstrated in human clinical trials (DAC version)
• Body composition improvement: lean mass increase and fat reduction observed in clinical settings
• Sleep architecture: community reports and the general GHRH literature suggest improved deep sleep, particularly with bedtime dosing
• Recovery and tissue repair: indirect, via elevated GH/IGF-1 environment
• Age-related GH decline: the primary clinical interest, though formal trials for this indication are limited

Community-Reported Protocols

The following reflects commonly discussed protocols. CJC-1295 is not FDA-approved for any human use. This information is included for reference and does not constitute medical advice.

CJC-1295 with DAC

• Reported dose: 2 mg per injection
• Reported frequency: once per week (some describe twice weekly at 1 mg)
• Reported cycle length: 8–12 weeks
• The long half-life means steady-state levels are reached after approximately 2–3 weeks

CJC-1295 without DAC (Mod GRF 1-29)

• Reported dose: 100–200 mcg per injection
• Reported frequency: 2–3 times daily
• Timing commonly described: fasted, before bed, morning fasted, and/or post-exercise
• Reported cycle length: 8–12 weeks on, followed by a break

Combined with ipamorelin

The most commonly discussed GH-related protocol pairs Mod GRF 1-29 with ipamorelin:

• Mod GRF 1-29: 100 mcg
• Ipamorelin: 200–300 mcg
• Described as combined in the same syringe
• 2–3 times daily, fasted
• Bedtime dose is described as the most important (to coincide with natural nocturnal GH surge)

Timing considerations frequently discussed

• Fasted state (minimum 2 hours after eating): carbohydrates and fats are reported to blunt GH release
• Avoiding injection near insulin spikes: insulin suppresses GH release
• Bedtime injection: described as amplifying the natural nocturnal GH surge

Side Effects and Safety Considerations

Commonly reported side effects

• Flushing or warmth: a warm sensation spreading from the injection site, described as more common with the DAC version, typically lasting 15–30 minutes
• Water retention: dose-dependent, a known GH class effect
• Tiredness: initial drowsiness, particularly with bedtime dosing
• Headache: occasionally reported
• Injection site reactions: consistent with subcutaneous injection generally
• Numbness or tingling: carpal tunnel-like symptoms at higher doses, a recognized GH class effect

Concerns specific to the DAC version

The sustained GH elevation from DAC may create a “bleed” effect, with continuous low-level GH rather than distinct pulses. Some practitioners suggest this is less physiological and potentially more likely to cause GH-related side effects (insulin resistance, water retention) than pulsatile release. The long half-life also means effects cannot be quickly reversed if problems emerge.

Monitoring considerations

For those using CJC-1295 under medical supervision, commonly discussed monitoring includes:

• IGF-1 levels: at baseline and periodically during use
• Fasting glucose and HbA1c: GH opposes insulin action
• Blood pressure: water retention can affect BP

How CJC-1295 Relates to Other Peptides

CJC-1295 belongs to the GHRH analog class. Here’s how it compares to related compounds:

• Sermorelin: also a GHRH analog, but with a shorter half-life (~10-20 min vs. ~30 min for Mod GRF). Sermorelin has the advantage of a former FDA approval and more extensive human safety data. CJC-1295 generally produces larger GH pulses per injection due to better enzymatic stability.
• Tesamorelin: the only currently FDA-approved GHRH analog (for HIV-associated lipodystrophy). Has the strongest clinical data for visceral fat reduction among GHRH analogs.
• Ipamorelin: works through a different pathway (ghrelin/GHS-R1a) and is described as synergistic when combined with CJC-1295. See our muscle growth guide.
• MK-677: an oral ghrelin mimetic, sometimes compared to CJC-1295 + ipamorelin combinations, though it operates through the GHS-R1a pathway rather than GHRH.
• GHRP-6 and GHRP-2: alternative ghrelin mimetics that can be combined with CJC-1295, though they are generally considered less selective than ipamorelin.
• Healing peptides like BPC-157 and TB-500: sometimes discussed in recovery contexts alongside GH secretagogues, since GH/IGF-1 elevation is thought to support tissue repair. See our injury recovery guide.

Legal Status

United States

CJC-1295 is not FDA-approved for any human use. It is available as a research chemical. Some anti-aging clinics have prescribed it off-label, though regulatory scrutiny of compounded GH secretagogue products has increased. The FDA has issued guidance expressing concern about these products.

Australia

Classified under Schedule 4 (prescription-only) by the TGA.

WADA

CJC-1295 is prohibited under Section S2. GH-releasing factors and their analogs are explicitly banned in competition and out of competition.

Frequently Asked Questions

Should I use CJC-1295 with or without DAC?

These are substantially different compounds in practice. The DAC version requires only weekly injection but creates sustained GH elevation that departs from natural pulsatile patterns. The no-DAC version (Mod GRF 1-29) requires multiple daily injections but produces GH pulses that more closely resemble natural physiology. Community preference has generally shifted toward the no-DAC version, often combined with ipamorelin.

How does CJC-1295 compare to sermorelin?

Both are GHRH analogs targeting the same receptor. CJC-1295 (no-DAC) has better enzymatic stability than sermorelin, resulting in a longer effective half-life (~30 min vs. ~10-20 min) and generally larger GH pulses. Sermorelin has the advantage of former FDA approval and more extensive human safety data. For those prioritizing proven safety, sermorelin is the more conservative choice.

Can CJC-1295 and ipamorelin be combined in the same syringe?

Community protocols commonly describe combining them in a single insulin syringe for injection. Both peptides are reported to be stable in the same solution.

Does CJC-1295 work as well in older adults?

GH response to GHRH stimulation declines with age due to reduced pituitary somatotroph capacity. Older adults are likely to see smaller absolute GH responses than younger individuals. However, clinically meaningful elevation remains achievable, particularly when a ghrelin mimetic like ipamorelin is used concurrently. The degree of response varies individually.

Will CJC-1295 show up on drug tests?

Standard workplace drug panels do not test for CJC-1295. WADA-level anti-doping tests can detect GH secretagogues. Athletes in WADA-tested sports should avoid it.

Does CJC-1295 suppress natural GH production?

Unlike exogenous GH injection, CJC-1295 works through the body’s own GHRH receptor system. The no-DAC version, which produces pulsatile GH release, is thought to be less likely to cause pituitary suppression than sustained GH elevation. However, the long-term effects of chronic GHRH receptor stimulation on pituitary function have not been thoroughly studied in humans.

References

1. Teichman SL, et al. “Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults.” J Clin Endocrinol Metab. 2006;91(3):799-805. PubMed
2. Alba M, et al. “Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout (GHRHKO) mouse.” Am J Physiol Endocrinol Metab. 2006;291(6):E1290-4. [research needed]
3. Ionescu M, Bhatt DL. “Growth hormone-releasing hormone and growth hormone-releasing peptide-6 exert synergistic effects on GH release in adult normal volunteers.” J Clin Endocrinol Metab. 2006. [research needed]
4. Nass R, et al. “Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults.” Ann Intern Med. 2008;149(9):601-11. PubMed

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