CJC-1295 (No DAC) vs MK-677 (Ibutamoren)
A modified growth hormone-releasing hormone that boosts your body's natural GH pulses for better recovery, deeper sleep, and improved body composition [13] [17].
The oral growth hormone secretagogue that tricks your body into producing more GH — no needles required.
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
CJC-1295 (No DAC)
100–100 mcg
MK-677 (Ibutamoren)
25–25 mg
Frequency
CJC-1295 (No DAC)
Once daily
MK-677 (Ibutamoren)
Once daily
Administration
CJC-1295 (No DAC)
Subcutaneous injection
MK-677 (Ibutamoren)
Oral (capsule or liquid)
Cycle length
CJC-1295 (No DAC)
8-12 weeks
MK-677 (Ibutamoren)
8-12 weeks
Onset speed
CJC-1295 (No DAC)
Moderate (1-2 weeks)
MK-677 (Ibutamoren)
Moderate (1-2 weeks)
Evidence level
CJC-1295 (No DAC)
Moderate human trials (Phase 1-2)
MK-677 (Ibutamoren)
Moderate human trials (Phase 1-2)
Benefit ratings
GH Stimulation
Sleep Quality
Recovery Support
Muscle and body composition
Recovery and athletic performance
Sleep quality and metabolic health
Compound specifications
CJC-1295 (No DAC)
Molecular formula
C152H252N44O42
Molecular weight
3367.9 g/mol
Half-life
30 minutes to 2 hours
Bioavailability
~100% (subcutaneous)
CAS number
863288-34-0
MK-677 (Ibutamoren)
Molecular formula
C27H36N4O5S
Molecular weight
528.7 g/mol
Half-life
4-6 hours (IGF-1 elevation persists ~24 hours)
Bioavailability
High oral bioavailability
CAS number
159634-47-6
Dosing compared
CJC-1295 (No DAC)
Subcutaneous
100 mcg
Once daily, 30 minutes before bed · 2-4 weeks
A common starting dose used in research practice. Because the no-DAC form is short-acting (about 30 minute half-life), it is injected on an empty stomach for the best growth-hormone pulse.
100 mcg per dose
1-2 times daily · 8-12 weeks
The typical maintenance dose used in practice, often given before bed and/or after fasted exercise. Frequently paired with a GH-releasing peptide.
100 mcg per dose
2-3 times daily · 8-12 weeks
A higher-frequency plan used by experienced users to mimic natural GH pulses across the day, each dose taken fasted.
MK-677 (Ibutamoren)
Oral
Weeks 2-4
10 mg
Once daily · 2-4 weeks initial
Lower entry dose used in practice to limit water retention and appetite surge before titrating up.
Studied up to 1-2 years
25 mg
Once daily · Studied up to 1-2 years
25 mg once-daily oral is the dose used in the randomized trial in healthy older adults; increased GH/IGF-1 and fat-free mass [1]. Most-studied dose [2].
Best suited for
CJC-1295 (No DAC)
Natural Growth Hormone Optimization
Perfect for those wanting to boost their body's own GH production rather than using synthetic growth hormone. Mimics the natural pulsatile release pattern your pituitary uses [2].
Workout Recovery and Muscle Building
Athletes and fitness enthusiasts use it to accelerate recovery between training sessions, support lean muscle development, and reduce body fat over time [17] [18].
Sleep Quality Enhancement
Because GH is naturally released during deep sleep, many users report dramatically improved sleep quality with more vivid dreams and feeling more refreshed upon waking [12] [13].
Anti-Aging and Vitality
As GH levels decline with age, CJC-1295 helps restore more youthful hormone patterns, potentially improving skin quality, energy levels, and overall well-being [16] [17] [20].
Synergistic Peptide Stacking
Designed to work hand-in-hand with GHRPs like Ipamorelin. When combined, these peptides amplify each other's effects for significantly greater GH release than either alone [9].
MK-677 (Ibutamoren)
Older Adults (60+) Seeking Body Composition Improvements
MK-677 was designed for aging populations. It restores GH and IGF-1 to youthful levels, [7] increases lean mass, and improves physical function in people over 60. A 2-year clinical trial showed a 1.1 kg gain in fat-free mass [1] with only modest fat gain—ideal for maintaining strength in older age.
Athletes and Fitness Enthusiasts Wanting Recovery Support
Oral dosing makes MK-677 convenient for athletes. It enhances muscle protein synthesis, speeds recovery after intense training, and supports lean mass building without the hassle of injections.
People with Chronic Wasting or Protein Deficiency
Clinical trials show MK-677 helps treat protein-energy wasting in kidney disease and other conditions. [2] It stimulates appetite (a feature in these populations) and preserves muscle tissue—making it useful for those losing mass despite good nutrition.
Side effects
CJC-1295 (No DAC)
Common
- Injection site reactions
- Flushing or warmth
- Water retention
- Increased appetite
Uncommon
- Tingling or numbness
- Headache
Serious
- Allergic reaction
MK-677 (Ibutamoren)
Common
- Increased appetite
- Mild water retention or edema
- Elevated fasting glucose
Uncommon
- Joint or muscle pain
- Carpal tunnel syndrome or nerve compression symptoms
- Mild nausea or digestive upset
Serious
- Glucose dysregulation and diabetes risk
Safety & evidence
CJC-1295 (No DAC)
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
CJC-1295 without DAC itself has not been evaluated in controlled human clinical trials; expectations about its safety are extrapolated from studies of related GHRH analogs. The most common side effects are mild and include injection site reactions and temporary flushing [19]. Because it stimulates natural GH release rather than providing exogenous GH, it maintains the body's feedback mechanisms [2].
Contraindications
- Active cancer or history of cancer
- Pregnancy or breastfeeding
- Pituitary tumors or disorders
- Hypersensitivity to GHRH analogs
- Diabetic retinopathy
MK-677 (Ibutamoren)
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
MK-677 has been studied in hundreds of humans over 2+ years and is generally well tolerated. [1][3] Most side effects are mild and manageable, especially with lower starting doses. The lack of injection requirement makes it safer than injectable GH in terms of infection risk and sterility concerns. However, it is not FDA approved and should be viewed as a research compound.
Contraindications
- Uncontrolled diabetes or severe glucose dysregulation
- Active cancer or high cancer risk requiring caution with IGF-1 elevation
- Pregnancy or breastfeeding
Which is right for you?
Choose CJC-1295 (No DAC) if...
- Increasing natural growth hormone levels
- Building lean muscle mass
- Improving sleep quality
- Enhancing workout recovery
Choose MK-677 (Ibutamoren) if...
- Building lean muscle mass and strength
- Improving overall body composition in aging adults
- Enhancing athletic recovery and performance
- Supporting metabolic health and fat loss