HGH Fragment 176-191 vs MK-677 (Ibutamoren)
Side-by-side comparison of key properties, dosing, and research.
Fat Loss & Metabolic
HGH Fragment 176-191Growth Hormone Peptides
MK-677 (Ibutamoren)- Summary
- HGH Fragment 176-191 (also known as AOD-9604) is a stabilized, modified fragment of the human growth hormone molecule corresponding to amino acids 176–191 with an addition of a tyrosine residue at the N-terminus. It retains HGH's fat-burning properties without the anabolic, diabetogenic, or IGF-1-stimulating effects.
- 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
- ~30 minutes
- 24 hours
- Admin Route
- SubQ
- Oral
- Research
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- Typical Dose
- 250–500 mcg
- 10–25 mg
- Frequency
- 1–3 times daily
- Once daily
- Key Benefits
- Selective fat burning without anabolic side effects
- Reduces visceral and subcutaneous fat
- No insulin resistance or blood glucose disruption
- Does not stimulate IGF-1
- May support cartilage and bone repair (at higher doses)
- No effect on growth or organ size
- 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
- Injection site irritation
- Temporary lethargy
- Headache (rare)
- Nausea (rare)
- 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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