CJC-1295 (No DAC) vs MK-677
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), engineered for a long duration of action. The form most people mean by CJC-1295 includes a Drug Affinity Complex (DAC) that binds blood albumin to extend its half-life to roughly 6 to 8 days, raising GH and IGF-I for days from a single injection. It was developed by ConjuChem, reached Phase II trials and was abandoned; it is not an approved drug and is sold only as a research chemical. A version without DAC (Modified GRF 1-29) acts for only about 30 minutes.
Also: Ibutamoren, Nutrobal
MK-677 (ibutamoren) is not actually a peptide, it is a small, orally active non-peptide molecule that mimics ghrelin, your hunger and growth-hormone hormone. Taken as a daily pill, it reliably pushes up growth hormone and IGF-1 levels, which is why it is popular for muscle and recovery. It has been through real human trials but was never approved as a drug, and the trials that mattered most for older adults and Alzheimer's came up short.
Key Comparison Insights
- Both peptides belong to the Growth Hormone category, suggesting similar primary applications.
Detailed Comparison
| Attribute | CJC-1295 (No DAC) | MK-677 |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| FDA Status | Not FDA Approved | Not 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. | MK-677 is a selective agonist of the growth hormone secretagogue receptor (GHS-R1a), the same receptor the hormone ghrelin binds. By activating that receptor in the pituitary and hypothalamus, it triggers pulses of growth hormone release, which in turn raises IGF-1 (insulin-like growth factor 1) from the liver. Because it copies ghrelin, it also tends to increase appetite, and it can nudge up cortisol levels too. The effect is sustained because it is long-acting and orally available, unlike injectable peptides that mimic ghrelin or growth-hormone-releasing hormone. |
| Common Dosing | 100 mcg daily (no DAC) or 2 mg weekly (with DAC) Daily (no DAC) or 1-2x weekly (with DAC) | 10-25 mg daily Once daily, often before bed |
| Administration | Subcutaneous injection | Oral |
| Typical Duration | 8-12 weeks | 8-12 weeks or longer |
| Best Time to Take | Before bed | Before bed |
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. 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. An earlier study showed once-daily CJC-1295 normalized growth in GHRH-knockout mice. Beyond pharmacokinetics and hormone levels, there are no large long-term human trials demonstrating clinical benefits like fat loss or muscle gain, so those claims are not established by published trials. 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. Bottom line: the GH and IGF-I-raising effect and long half-life are well supported, while real-world efficacy and long-term safety are not. | MK-677 has unusually good human data for a compound sold in the gray market, and the data is a mix of clear wins and clear failures. In a one-year randomized trial of 65 healthy older adults (Annals of Internal Medicine, 2008), 25 mg daily raised IGF-1 and increased fat-free mass, basically lean tissue, though much of the early body-weight gain was water and the functional strength benefits were not impressive. In Alzheimer's disease, a large 563-patient, 12-month randomized trial (Neurology, 2008) confirmed it raised IGF-1 but did nothing to slow cognitive decline. Across studies the consistent downsides are increased appetite, fluid retention, and reduced insulin sensitivity (higher blood sugar). So the muscle-and-IGF-1 effect is real and well documented, but MK-677 failed its biggest disease trials, remains unapproved, and is banned in sport by WADA. |
Frequently Asked Questions: CJC-1295 (No DAC) vs MK-677
What is the difference between CJC-1295 (No DAC) and MK-677?
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), engineered for a long duration of action. the form most people mean by cjc-1295 includes a drug affinity complex (dac) that binds blood albumin to extend its half-life to roughly 6 to 8 days, raising gh and igf-i for days from a single injection. it was developed by conjuchem, reached phase ii trials and was abandoned; it is not an approved drug and is sold only as a research chemical. a version without dac (modified grf 1-29) acts for only about 30 minutes. MK-677 is a growth hormone peptide that mk-677 (ibutamoren) is not actually a peptide, it is a small, orally active non-peptide molecule that mimics ghrelin, your hunger and growth-hormone hormone. taken as a daily pill, it reliably pushes up growth hormone and igf-1 levels, which is why it is popular for muscle and recovery. it has been through real human trials but was never approved as a drug, and the trials that mattered most for older adults and alzheimer's came up short. The main differences lie in their mechanisms of action and clinical applications.
Which is better, CJC-1295 (No DAC) or MK-677?
Neither is universally "better" - the choice depends on your specific goals. CJC-1295 (No DAC) is typically used for growth hormone purposes, while MK-677 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 MK-677 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using CJC-1295 (No DAC) and MK-677 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.