IGF-1 LR3 vs MK-677 (Ibutamoren)
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
IGF-1 LR3Growth Hormone Peptides
MK-677 (Ibutamoren)- Summary
- IGF-1 LR3 is a synthetic analog of Insulin-like Growth Factor-1 with an extended half-life. It is one of the most potent anabolic peptides available, directly stimulating muscle cell hyperplasia and hypertrophy, and is the downstream mediator of many of GH's anabolic 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
- 20–30 hours
- 24 hours
- Admin Route
- SubQ, IM
- Oral
- Research
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- Typical Dose
- 40–80 mcg
- 10–25 mg
- Frequency
- Once daily or split twice daily
- Once daily
- Key Benefits
- Direct muscle hypertrophy via IGF-1R stimulation
- Muscle hyperplasia (new fiber formation) — unique among peptides
- Rapid gains in lean muscle mass
- Accelerated recovery from training and injury
- Increased nutrient uptake by muscle cells
- Fat oxidation enhancement
- Bone density improvement
- Cartilage and connective tissue repair
- 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
- Hypoglycemia (significant risk — insulin-like activity)
- Acromegaly-like effects with excessive long-term use
- Jaw and hand swelling
- Organ hypertrophy with extreme doses
- +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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