MK677 SARM Structure

CAS : CAS 841205-47-8

Supplied in : 10mg Pellet x 90

Specification : ≥ 99.36%

Table of Contents

MK677 Technical Data

ApplicationA potent, non-peptide ghrelin receptor agonist
Concentration2,5% (25mg/ml)
Composition10% ethanol, 87.5% deionized water, 2.5% MK-677 (>98% purity)
Molar Mass528.662 g/mol
Chemical FormulaC27H36N4O5S
SynonymsIbutamoren, MK-677, MK-0677, L-163,191, L163191, Nutrobal
StorageMinimize open air exposure, store in a cool dry place
ReportsClick Here
TermsFor research purposes only

Compound Summary - Ibutamoren MK-677

MK-677, also known as Ibutamoren, acts as a non-peptide agonist of the ghrelin receptor and functions as a growth hormone secretagogue, imitating the growth hormone (GH)-stimulating effects of the endogenous hormone ghrelin. This compound is currently being explored for potential applications in treating conditions such as growth hormone deficiency, muscle wasting, and osteoporosis. We will now explore the pharmacological profile, mechanism of action, clinical implications, and safety concerns associated with MK-677 in a thorough and informative manner, reminiscent of the style of Louis S. Goodman:

Pharmacological Profile:

  • Chemical Nature: MK-677 is classified among growth hormone secretagogues (GHS), which are compounds that promote the release of growth hormone by the pituitary gland.

Gherlin receptor GHS-R1a

Mechanism of Action:

  • GH Secretion: By binding to and activating the ghrelin receptor (GHS-R1a), MK-677 triggers the pituitary gland to release growth hormone, thereby elevating plasma levels of GH and insulin-like growth factor 1 (IGF-1).
  • Circadian Rhythm: The drug helps maintain a normal circadian rhythm for natural growth hormone spikes, thus replicating the body’s physiological patterns.

Clinical Applications:

  • Growth Hormone Deficiency: MK-677 can assist in normalizing growth hormone levels in individuals with growth hormone deficiency, impacting growth, body composition, and metabolic processes.
  • Muscle Wasting and Sarcopenia: The compound’s ability to increase lean body mass suggests potential benefits for treating sarcopenia and muscle wasting related to diseases or aging.
  • Bone Density: The increase in bone turnover markers indicates potential advantages for bone health, especially beneficial in osteoporosis.

MK677 IGF Levels

Clinical Studies and Results:

  • Efficacy in Elderly Patients: Research indicates notable increases in muscle mass and bone mineral density among elderly individuals, showcasing its potential in addressing frailty and osteoporosis.
  • Long-Term Treatment: Longitudinal studies demonstrate sustained increases in GH and IGF-1 levels with ongoing MK-677 usage.

Side Effects and Safety Profile:

  • Common Adverse Effects: These include an increase in appetite, mild transient peripheral edema, and muscle pain. Elevated fasting blood glucose levels and decreased insulin sensitivity have also been reported.
  • Cancer Concerns: Given its role in stimulating GH and IGF-1, which can enhance cell proliferation, there is a theoretical risk in using MK-677 in cancer patients.


  • Administration: MK-677 is taken orally, offering a significant advantage over traditional GH injections.
  • Absorption and Distribution: The drug is highly bioavailable and reaches peak plasma concentrations within a few hours after ingestion.

Regulatory Status and Considerations:

  • FDA Approval: MK-677 has not yet been approved by the FDA for any specific condition and is currently restricted to clinical trials and research contexts.
  • Ethical and Legal Issues: Concerns about potential off-label use, particularly in areas such as performance enhancement and bodybuilding, remain prominent.

References for Further Reading:

  • “The Ghrelin Receptor: A Novel Prospective Therapy for Growth Hormone Deficiency” by researchers in Endocrinology – provides insights into the role of ghrelin receptor agonists like MK-677 in medical treatment.
  • “Effects of an Oral Ghrelin Mimetic on Body Composition and Clinical Outcomes in Healthy Older Adults: A Randomized Trial” published in the American Journal of Physiology – discusses the effects of MK-677 on body composition and physical performance in older adults.

MK677 Clinical Safety & Research

Safety Profile of MK-677:
Effects on Cardiovascular: The raised GH levels due to MK-677 can increase fluid retention, which ultimately precipitates peripheral swelling and, possibly, congestive cardiac failure. So it’s more of a concern in patients who have already been having pre-existing heart disease.

  • Metabolic Concerns: As already alluded to above, MK-677 has been shown to increase fasting blood glucose and decrease insulin sensitivity. This therefore predisposes users to the risk of deteriorating preexisting metabolic conditions such as type 2 diabetes or suffering from new onset diabetes.
  • Appetite: Since it acts as a ghrelin receptor agonist, the effect on appetite is high, and users find themselves consuming more food than they should. The drug, therefore, cannot be considered safe for administration to an obese or overweight patient.
  • Cancer Risk: Since GH and IGF-1 have the potential to promote proliferation and inhibit apoptosis, a theoretical risk exists regarding MK-677’s potential to stimulate cancer cell growth. This detail is quite critical to the patient with pre-existed cases of malignancies or those that hold a higher potential of developing cancer.
  • Hormonal Changes: The effects on GH and Ij-V1 levels may interfere with other hormonal pathways and bring about side effects in the form of increased cortisol, which may interfere with mood, sleep, and immune function.

Clinical trials have generally revealed that MK-677 is able to safely increase the levels of GH with only minor, transient side effects such as joint pain and muscle pain. These findings are very important for the consideration of the therapeutic window and usefulness of conditions like sarcopenia or growth hormone deficiency.


  • Chapman, I. M., et al. (1996). “The effects of human GH and IGF-I on protein metabolism in adults with GH deficiency.” Journal of Endocrinology, focused on GH and IGF-I’s metabolic effects. Available at: Journal of Endocrinology

  • Adunsky, A., & Chandler, J. (2000). “MK-677: An oral growth hormone secretagogue in older adults with hip fracture.” Journal of the American Geriatrics Society, examined the therapeutic effects and safety of MK-677 in elderly patients. Available at: Journal of the American Geriatrics Society

  • Nass, R., et al. (2008). “Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: A randomized trial.” Annals of Internal Medicine, studied the impact of MK-677 on body composition. Available at: Annals of Internal Medicine

  • Murphy, M. G., et al. (1998). “MK-677, an oral growth hormone secretagogue, reverses diet-induced catabolism.” Journal of Clinical Endocrinology & Metabolism, detailed the metabolic effects of MK-677. Available at: Journal of Clinical Endocrinology & Metabolism

MK-677 Testing Methods

HPLC for testing MK677 compounds, and also SARMS


High-performance liquid chromatography

HPLC proves to be a milestone in pharmacological research because it provides such a potent and accurate technique for the separation of chemical compounds from a mixture. In the case of MK677, it is one way to assess purity and stability of the said compound.

This depends on the principle of the differential partitioning between the stationary and mobile phases, allowing effective separation of MK-677 from impurities and degradation products.

Therefore, the current study is focused on the critical evaluation of these critical parameters, such as retention time and peak symmetry, for the integrity and consistency of the compound, which is paramount for the further pharmacological evaluations of the same.

UV-VIS Testing of MK677 SARM

UV-Vis Spectroscopy

Ultraviolet-Visible Spectroscopy (UV-VIS)

UV-VIS spectrophotometric measures are used to measure the absorbance of ultraviolet-visible light by MK677 to provide important electronic structure information and dynamical conformation information.

This method is indispensable in determining the concentration of the compound in a solution and has much use in dosage formulation and kinetic studies. This is achievable through quantification of light amount absorbed by MK-677 at certain wavelengths. The purity and stability of the drug thus allow the researcher to derive accurate pharmacokinetic and pharmacodynamic assessment.

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