Ibutamoren
Also known as: MK-677, MK-0677, L-163,191
Ibutamoren is an orally active growth hormone secretagogue that stimulates the release of growth hormone and IGF-1 by mimicking the action of ghrelin at the growth hormone secretagogue receptor.
Ibutamoren is a 528.67 g/mol research peptide. Ibutamoren is an orally active growth hormone secretagogue that stimulates the release of growth hormone and IGF-1 by mimicking the action of ghrelin at the growth hormone secretagogue receptor.
Also called: MK-677, MK-0677, L-163,191
528.67 g/mol
Molecular Weight
Daltons
2
Strong Evidence
benefits
4
Studies Cited
peer-reviewed
10-25
Typical Dose
mg
Overview
Ibutamoren operates as a potent, long-acting growth hormone secretagogue that increases plasma levels of growth hormone and IGF-1 without affecting cortisol concentrations. Unlike traditional growth hormone replacement therapy, this compound works by binding to the ghrelin receptor in the hypothalamus and pituitary gland, triggering natural growth hormone release. The compound demonstrates excellent oral bioavailability and maintains elevated growth hormone levels for up to 24 hours after administration. Research shows ibutamoren can increase growth hormone levels by 50-90% and IGF-1 levels by 30-40% in healthy subjects. The compound also influences nitrogen balance, bone density, and body composition through its growth hormone-releasing properties.
Key Takeaways: Ibutamoren
- Strongest evidence supports Ibutamoren for increased growth hormone and igf-1 levels and enhanced muscle mass and strength
- Research doses typically range from 10 to 25 mg via oral
- 2 benefits with strong evidence, 3 moderate, 2 preliminary
- Half-life: 4-6 hours
- 4 cited research studies in this guide
Mechanism of Action
Ibutamoren functions as a selective agonist of the growth hormone secretagogue receptor (GHSR), also known as the ghrelin receptor. Upon binding to GHSR in the hypothalamus, it stimulates the release of growth hormone-releasing hormone (GHRH), which subsequently triggers growth hormone secretion from the anterior pituitary. The elevated growth hormone levels stimulate hepatic IGF-1 production, creating an anabolic environment that promotes protein synthesis, lipolysis, and bone formation. Unlike exogenous growth hormone, ibutamoren preserves the natural pulsatile release pattern of growth hormone, maintaining physiological feedback mechanisms.
Research Benefits
Ibutamoren at a Glance
Ibutamoren functions as a selective agonist of the growth hormone secretagogue receptor (GHSR), also known as the ghrelin receptor.
Increased Growth Hormone and IGF-1 Levels
Strong EvidenceElevates growth hormone levels by 50-90% and IGF-1 by 30-40% through ghrelin receptor activation, maintaining natural pulsatile release patterns that support physiological feedback mechanisms.
Enhanced Muscle Mass and Strength
Strong EvidencePromotes lean body mass gains through increased protein synthesis and nitrogen retention, with studies showing 1.1-2.0 kg increases in lean mass over 8-12 weeks of administration.
Improved Bone Mineral Density
Moderate EvidenceStimulates osteoblast activity and collagen synthesis, leading to increased bone formation markers and improved bone density, particularly beneficial for age-related bone loss.
Enhanced Sleep Quality
Moderate EvidenceIncreases REM sleep duration and sleep efficiency by 20-50%, likely through modulation of growth hormone release patterns that naturally occur during deep sleep phases.
Improved Body Composition
Moderate EvidenceReduces visceral adipose tissue while increasing lean mass through enhanced lipolysis and protein synthesis, resulting in favorable changes to body fat percentage.
Accelerated Wound Healing
PreliminaryEnhances tissue repair and regeneration through increased IGF-1 expression and growth factor signaling, promoting faster recovery from injuries and surgical procedures.
Neuroprotective Effects
PreliminaryDemonstrates potential cognitive benefits through IGF-1-mediated neuroplasticity and neuroprotection, with research suggesting improved memory and learning capacity.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| Growth hormone elevation studies | 10–25 mg | oral |
| Body composition research | 12.5–25 mg | oral |
Frequency
Once daily
Timing
Evening administration 2 hours before bedtime or upon waking
Cycle Length
8-12 weeks with 4-6 week breaks
Research Notes
- 1Take on empty stomach for optimal absorption
- 2Evening dosing may enhance sleep-related growth hormone release
- 3Effects on growth hormone typically appear within 1-2 weeks
- 4Morning dosing may reduce potential sleep disruption in sensitive individuals
- 5Consistent timing important for maintaining stable hormone levels
Reconstitution Guide
Standard Reconstitution
Vial Size
0 mg
Bacteriostatic Water
0 mL
Concentration
NaN mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
Ibutamoren vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 0 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at Room temperature in sealed container. 2-3 years when stored properly.
Storage Temperature
Room temperature in sealed container
Shelf Life
2-3 years when stored properly
Important Notes
- •Available as oral capsules or powder
- •Protect from light and moisture
- •No reconstitution required for oral formulations
- •Store in cool, dry place away from direct sunlight
Ibutamoren Dosing Calculator
Calculate daily intake, cycle totals, and vials needed with pre-filled protocols →
Ibutamoren Reconstitution Calculator
Calculate concentration, syringe units, and doses per vial with auto-filled values →
Safety & Side Effects
Reported Side Effects
- !Increased appetite and water retention
- !Transient muscle pain and joint stiffness
- !Numbness and tingling in extremities
- !Elevated blood glucose and insulin resistance
- !Lethargy and fatigue during initial weeks
- !Temporary increase in blood pressure
- !Mild to moderate edema
- !Sleep disturbances and vivid dreams
- !Headaches and dizziness
- !Potential impact on thyroid function
Potential Interactions
- ⚡May enhance insulin sensitivity medications effects
- ⚡Potential interaction with corticosteroids affecting growth hormone response
- ⚡Blood pressure medications may require monitoring and adjustment
- ⚡Sleep medications effects may be altered due to sleep pattern changes
- ⚡Diabetes medications may need adjustment due to glucose effects
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
A double-blind, placebo-controlled trial of ibutamoren mesylate on bone mineral density in postmenopausal women
12-month study in 292 postmenopausal women showing ibutamoren increased bone formation markers by 60% and IGF-1 levels by 81%, with improvements in bone mineral density.
Effects of a 7-day treatment with a novel, orally active, growth hormone secretagogue on 24-hour growth hormone profiles
Demonstrated that ibutamoren increased 24-hour growth hormone area under the curve by 97% and IGF-1 levels by 39% in healthy young men.
Ibutamoren mesylate promotes nitrogen retention in healthy elderly subjects
8-week study showing ibutamoren improved nitrogen balance and increased lean body mass in elderly subjects, with minimal side effects.
The effects of MK-677 on body composition and functional outcomes in older adults
Research demonstrating significant improvements in lean mass, bone density, and physical function in elderly participants over 12 weeks of treatment.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
Ibutamoren stimulates natural growth hormone production through ghrelin receptor activation, while synthetic growth hormone replaces endogenous production. Ibutamoren preserves natural pulsatile release patterns and can be taken orally, whereas growth hormone requires injection and bypasses natural regulatory mechanisms.
Growth hormone levels typically increase within 1-2 hours of administration, with peak effects occurring 2-4 hours post-dose. Physical changes like improved sleep quality may appear within 1-2 weeks, while body composition changes typically become noticeable after 4-6 weeks of consistent use.
Research suggests cycling ibutamoren in 8-12 week periods with 4-6 week breaks helps prevent receptor desensitization and maintains effectiveness. Continuous long-term use may lead to diminished growth hormone response and increased risk of side effects.
Ibutamoren can increase blood glucose levels and reduce insulin sensitivity in some individuals. While it doesn't directly cause diabetes, it may worsen glucose control in predisposed individuals. Regular blood glucose monitoring is recommended during research periods.
Evening dosing 2 hours before bedtime aligns with natural growth hormone release patterns and may enhance sleep quality. Some researchers prefer morning dosing to avoid potential sleep disruption. Consistent timing is more important than specific timing.
Unlike exogenous growth hormone, ibutamoren works through natural pathways and maintains feedback mechanisms. However, extended use may lead to some degree of adaptation. Taking breaks between cycles helps preserve natural production capacity.
Water retention typically ranges from 2-5 pounds during the first 2-4 weeks of use. This effect is generally dose-dependent and often subsides as the body adapts. The retention is usually intracellular and contributes to muscle fullness.
Research includes both male and female subjects with similar efficacy and safety profiles. Women may experience benefits for bone density and body composition, though individual responses vary. Pregnancy and breastfeeding are contraindications for research use.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.