MK-677 (Ibutamoren)
Active Substance: MK-677
Description
MK-677, also known by its International Nonproprietary Name (INN) Ibutamoren, is a compound that acts as a growth hormone secretagogue. This means it stimulates the body's pituitary gland to produce and secrete growth hormone (GH) and insulin-like growth factor 1 (IGF-1). It is an orally active, non-peptide compound that mimics the action of the hormone ghrelin. Other names for it include MK-0677, L-163,191, and the former tentative brand name Oratrope.
Side Effects and Benefits
Benefits:
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Increased Muscle Mass and Strength: By raising GH and IGF-1 levels, MK-677 can lead to an increase in lean body mass.
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Improved Recovery: Enhanced GH levels can accelerate post-workout recovery, allowing for more frequent and intense training.
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Better Sleep Quality: Some studies suggest that MK-677 can improve sleep architecture, particularly by increasing REM sleep and slow-wave sleep.
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Fat Loss: It may help promote fat loss while preserving lean muscle mass, contributing to a more "shredded" physique.
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Potential Anti-Aging Effects: The increase in GH and IGF-1 is associated with benefits like improved skin health and overall vitality.
Side Effects:
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Increased Appetite and Hunger: Because it mimics ghrelin, the "hunger hormone," one of the most common side effects is a significant increase in appetite.
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Water Retention (Edema): Users may experience bloating or swelling, particularly in the face, fingers, and ankles.
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Insulin Resistance: MK-677 can increase fasting blood glucose levels and decrease insulin sensitivity, potentially raising the risk of developing type 2 diabetes with long-term use.
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Lethargy or Fatigue: Some users report feeling tired or lethargic.
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Numbness or Tingling (Paresthesia): A common side effect is a sensation of numbness or tingling in the hands and feet.
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Joint and Muscle Pain: Some individuals may experience joint pain, which is thought to be related to the increased water retention and GH levels.
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Cardiovascular Risks: A clinical trial was stopped early due to concerns that MK-677 might increase the rate of congestive heart failure in certain patients.
Pros and Cons
Pros:
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Oral Administration: It is taken by mouth, which is a convenient alternative to injectable GH.
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No Suppression of Natural Hormone Production: Unlike anabolic steroids, MK-677 does not suppress the body's natural production of hormones like testosterone, LH, or FSH.
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Anabolic Effects: It promotes muscle growth and recovery, making it appealing to athletes and bodybuilders.
Cons:
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Not FDA-Approved: MK-677 is an investigational drug and is not approved for human consumption. Its long-term safety profile is not established.
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Significant Side Effects: The potential for increased blood sugar and insulin resistance is a serious health risk. Water retention and increased appetite can be uncomfortable and difficult to manage.
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Illegal in Competitive Sports: It is on the World Anti-Doping Agency (WADA) Prohibited List and is banned in most sports.
Dosage and Frequency
Typical dosages range from 10 to 25 mg per day, with many users starting at a lower dose to assess tolerance and mitigate side effects. Some advanced users may go as high as 30 mg per day. The frequency is typically once daily due to its long-lasting effects. Dosing is often done before bed, as the GH pulse it stimulates can improve sleep, and the increased appetite may be less of an issue while sleeping.
Half-Life and Detection Time
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Half-Life: The half-life of MK-677 is approximately 24 hours in humans, meaning a single dose can sustain elevated IGF-1 levels for a full day.
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Detection Time: While a single dose can be detected in urine for about 4 days, the detection window can be longer with continuous use. The exact detection time depends on the specific drug-testing method used, but it can be detectable for several weeks.
Hormonal Effects
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Sterogenic/Progestronic/Androgenic Effects: MK-677 is a growth hormone secretagogue, not a steroid. It does not have any direct sterogenic, progestronic, or androgenic effects. This is a key difference from anabolic steroids, which can have strong androgenic and progestogenic effects and can suppress natural testosterone production.
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Prolactin Effects: While MK-677 is primarily known for its effect on GH and IGF-1, the ghrelin receptor is also involved in prolactin release. Some anecdotal reports and limited studies suggest it may cause a slight increase in prolactin levels, though this is not a universally reported or well-established side effect.
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Anabolic-Androgenic Ratio: Since MK-677 is not a steroid and does not have androgenic properties, it does not have an anabolic-androgenic ratio. This ratio is a metric used to compare the anabolic (muscle-building) and androgenic (masculinizing) effects of anabolic steroids.
Pharmacological Properties
Half Life
1 days
Active Dose
100%
Detection
5.00 days
Concentration
10 mg/cap
Anabolic/Androgenic Profile
Usage Effectiveness
Activity Profile
Estrogenic
None
Progestanic
None
Water Retention
None
Aromatization
No
Benefits
Dosage Recommendations
Beginner
10-20 mg/week
Intermediate
20-30 mg/week
Advanced
30-40 mg/week
Evidence-based planning resources
Dive deeper into MK-677 (Ibutamoren) cycle design, stacking options, and harm-reduction checklists available inside Anabolic Planner.
- MK-677 (Ibutamoren) compound database overviewCompare MK-677 (Ibutamoren) with other sarm agents in the structured compound index.
- MK-677 (Ibutamoren) stack and cycle templatesReview evidence-based cycle outlines, dose progressions, and PCT pairings that incorporate MK-677 (Ibutamoren).
- Harm-reduction guide for MK-677 (Ibutamoren)Refresh safety monitoring, lab work, and countermeasure strategies tailored for MK-677 (Ibutamoren) protocols.
Peer-reviewed reference material
Validate mechanisms, contraindications, and regulatory guidance for MK-677 (Ibutamoren) with trusted clinical databases.
- MK-677 clinical research on PubMedSearch peer-reviewed human and veterinary studies discussing efficacy, endocrine impact, and contraindications.
- MK-677 pharmacology via Drug Information PortalReview mechanisms, synonyms, regulatory status, and toxicology summaries from the U.S. National Library of Medicine.
Side Effects
Common
Rare
Severe
Safety Information
Liver Toxicity
Low
Kidney Toxicity
Low
Cardiovascular Risk
Low
Disclaimer: This information is for educational purposes only. Always consult with a qualified healthcare professional before using any compounds.