CJC-1295 (No DAC) vs Mecasermin
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: CJC-1295 DAC, CJC-1295 no DAC
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), specifically a modified GHRH(1-29). The name covers two different products. CJC-1295 with DAC (Drug Affinity Complex) binds blood albumin, which stretches its half-life to roughly 6 to 8 days and raises GH and IGF-I for days from a single injection; this is the version ConjuChem took to Phase II before abandoning it, and the version the human data are about. CJC-1295 without DAC (Modified GRF 1-29, the form this page is named for) lacks the albumin tether and is much shorter acting, though its human half-life has not been formally published. Neither is an approved drug, both are sold only as research chemicals, and GHRH analogs are banned in sport by WADA.
Also: Increlex, rhIGF-1
Mecasermin is recombinant human IGF-1, identical to the 70-amino-acid hormone your liver makes in response to growth hormone. Sold as Increlex, it was FDA approved in 2005 for a narrow group: children with severe primary IGF-1 deficiency (mostly Laron syndrome) or a growth hormone gene deletion with antibodies against GH. In those kids it is the only thing that works, because GH cannot do its job. It is not a GH substitute, and its real risks (low blood sugar, tonsil overgrowth, cancer warnings) are why it stays a specialist drug.
Key Comparison Insights
- Mecasermin is FDA approved, while CJC-1295 (No DAC) remains in research stages.
- Both peptides belong to the Growth Hormone category, suggesting similar primary applications.
- Mecasermin has stronger research evidence (FDA Approved) compared to CJC-1295 (No DAC) (Limited Human Data).
Detailed Comparison
| Attribute | CJC-1295 (No DAC) | Mecasermin |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| FDA Status | Not FDA Approved | FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | CJC-1295 acts at the GHRH receptor on pituitary somatotroph cells, the same receptor the body's own GHRH uses, prompting the pituitary to synthesize and release growth hormone. Native GHRH is broken down within minutes; CJC-1295 with DAC carries a reactive group that covalently bonds to circulating albumin after injection, shielding it from breakdown and stretching its half-life from minutes to days. The sustained GH elevation drives the liver to produce IGF-I, the downstream hormone behind many of GH's tissue effects. There are two versions: with DAC (long-acting, albumin-binding) and without DAC (Modified GRF 1-29), which lacks the albumin tether. Because it works through the pituitary, it relies on the gland's own GH-producing capacity. | Normally, growth hormone binds receptors in the liver and other tissues and triggers IGF-1 production. IGF-1 then activates the type 1 IGF receptor on bone, cartilage and other cells, driving growth. In Laron syndrome the GH receptor is broken, so GH levels are high but IGF-1 stays low. Mecasermin skips the broken step and supplies IGF-1 directly. Because the IGF-1 receptor is a close relative of the insulin receptor, and because IGF-1 can also bind the insulin receptor at higher levels, it lowers blood sugar. That is why the label says to give it within about 20 minutes of a meal or snack. It is mostly carried by IGF binding protein 3 in blood, and its clearance depends on IGFBP-3 levels; the label reports a mean terminal half-life of about 5.8 hours in children with severe primary IGF-1 deficiency. |
| Common Dosing | 100 mcg daily (no DAC) or 2 mg weekly (with DAC) Daily (no DAC) or 1-2x weekly (with DAC) | 0.04-0.08 mg/kg twice daily to start Twice daily |
| Administration | Subcutaneous injection | Subcutaneous injection, rotating sites, within about 20 minutes before or after a meal or snack |
| Typical Duration | 8-12 weeks | Long-term, until growth plates close (closed epiphyses are a contraindication) |
| Best Time to Take | Before bed | Shortly before or after a meal or snack, twice daily |
Possible Side Effects May vary by individual |
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| Research Summary | The key human study is Teichman et al. (2006) in the Journal of Clinical Endocrinology and Metabolism, a randomized, double-blind, placebo-controlled ascending-dose trial in healthy adults using the DAC version. A single subcutaneous injection raised mean plasma GH 2- to 10-fold for 6 days or more and IGF-I 1.5- to 3-fold for 9 to 11 days, with cumulative effects on repeat dosing, and was reported as safe and relatively well tolerated short-term. A follow-up study in healthy men found GH still came in pulses rather than a flat line, with trough GH levels rising sharply. An earlier study showed once-daily CJC-1295 normalized growth in GHRH-knockout mice. These are hormone-level and pharmacokinetic studies, not outcome trials: there are no long-term human trials showing fat loss or muscle gain, and no published randomized trial of the popular CJC-1295 plus ipamorelin combination. The no-DAC form has essentially no published human data of its own. Development was halted after Phase II; a single trial death was attributed by the attending physician to pre-existing coronary artery disease rather than the drug, which is reported but not independently confirmed. FDA has also noted reported adverse events including increased heart rate and a systemic vasodilatory reaction. Bottom line: the GH and IGF-I-raising effect of the DAC version is well supported, while real-world efficacy and long-term safety are not. | The approval rests on five pooled studies (four open-label, one placebo-controlled) in 71 children with severe primary IGF-1 deficiency, 87% of whom had Laron syndrome. Height velocity rose from 2.8 cm per year before treatment to 8.0 cm per year in year 1, then settled around 4.5 to 5.8 cm per year in later years, still above baseline. Height scores improved but these children stayed very short (mean height SDS went from -6.7 to about -5.2 after 8 years), so it helps rather than normalizes. Hypoglycemia was reported in 42% of children at least once, and tonsillar hypertrophy in 15%. The label carries warnings for hypoglycemic seizures, anaphylaxis, intracranial hypertension, slipped capital femoral epiphysis (added July 2025), scoliosis progression, and postmarketing reports of malignant neoplasms; malignancy is a contraindication. Ownership changed recently: Eton Pharmaceuticals bought Increlex from Ipsen in December 2024 and in 2025 licensed rights outside the US to Esteve. Adult use, anti-aging use, and bodybuilding use are off-label and unsupported by trials. |
Frequently Asked Questions: CJC-1295 (No DAC) vs Mecasermin
What is the difference between CJC-1295 (No DAC) and Mecasermin?
CJC-1295 (No DAC) is a growth hormone peptide that cjc-1295 is a synthetic analog of growth hormone-releasing hormone (ghrh), specifically a modified ghrh(1-29). the name covers two different products. cjc-1295 with dac (drug affinity complex) binds blood albumin, which stretches its half-life to roughly 6 to 8 days and raises gh and igf-i for days from a single injection; this is the version conjuchem took to phase ii before abandoning it, and the version the human data are about. cjc-1295 without dac (modified grf 1-29, the form this page is named for) lacks the albumin tether and is much shorter acting, though its human half-life has not been formally published. neither is an approved drug, both are sold only as research chemicals, and ghrh analogs are banned in sport by wada. Mecasermin is a growth hormone peptide that mecasermin is recombinant human igf-1, identical to the 70-amino-acid hormone your liver makes in response to growth hormone. sold as increlex, it was fda approved in 2005 for a narrow group: children with severe primary igf-1 deficiency (mostly laron syndrome) or a growth hormone gene deletion with antibodies against gh. in those kids it is the only thing that works, because gh cannot do its job. it is not a gh substitute, and its real risks (low blood sugar, tonsil overgrowth, cancer warnings) are why it stays a specialist drug. The main differences lie in their mechanisms of action and clinical applications.
Which is better, CJC-1295 (No DAC) or Mecasermin?
Neither is universally "better" - the choice depends on your specific goals. CJC-1295 (No DAC) is typically used for growth hormone purposes, while Mecasermin is used for growth hormone. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can CJC-1295 (No DAC) and Mecasermin be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using CJC-1295 (No DAC) and Mecasermin together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.