GHRP-6 vs MK-677 (Ibutamoren)
Side-by-side comparison of key properties, dosing, and research.
Growth Hormone Peptides
GHRP-6Growth Hormone Peptides
MK-677 (Ibutamoren)- Summary
- GHRP-6 is the original synthetic GH-releasing peptide and a potent ghrelin receptor agonist. It produces strong GH pulses but is notorious for a significant hunger surge 30–45 minutes post-injection. This hunger side effect makes it less preferred than Ipamorelin or GHRP-2 for most protocols but can be useful in patients with appetite deficiency.
- MK-677 (Ibutamoren) is an orally active, non-peptide ghrelin receptor agonist that increases growth hormone and IGF-1 levels. Unlike injectable GHRPs, it can be taken orally and has a 24-hour half-life, making it convenient for sustained GH optimization.
- Half-Life
- 15–60 minutes
- 24 hours
- Admin Route
- SubQ, Intranasal
- Oral
- Research
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- Typical Dose
- 100–300 mcg
- 10–25 mg
- Frequency
- 2–3 times daily
- Once daily
- Key Benefits
- Strong GH stimulation
- Elevated IGF-1
- Muscle growth and recovery support
- Potential anti-inflammatory effects at GI level
- Useful for patients with appetite deficiency or cachexia
- Enhanced recovery from training
- Increases lean muscle mass
- Enhances bone density
- Improves sleep quality and REM sleep
- Accelerates recovery from training
- Increases appetite
- May improve skin elasticity and appearance
- Supports fat loss while maintaining muscle
- Oral administration — no injections required
- 24-hour half-life allows once-daily dosing
- Side Effects
- Intense hunger surge (30–45 min post-injection)
- Water retention
- Elevated cortisol (modest)
- Elevated prolactin (modest)
- +2 more
- Increased appetite (significant in some users)
- Water retention and puffiness
- Elevated blood glucose / insulin resistance (monitor in diabetics)
- Lethargy initially
- +2 more
- Stacks With
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