MK-677 (Ibutamoren) #

• Other Names: Ibutamoren, Nutrobal
• Primary Functions and Actions:
  • Stimulates the release of growth hormone (GH).
  • Increases insulin-like growth factor 1 (IGF-1) levels.
  • Increases appetite.
• Mechanism of Action:
  • MK-677 is a growth hormone secretagogue receptor agonist.
  • It binds to the ghrelin receptor (also known as the growth hormone secretagogue receptor) in the pituitary gland and hypothalamus.
  • This binding stimulates GH release and increases ghrelin levels, which can increase appetite.
• Systems Activated:
  • Endocrine System: Primarily affects the growth hormone axis.
• Dosage and Timing:
  • Common dosages range from 10-25 mg per day.
  • Administered orally.
  • Often taken before bedtime.
• Contraindications and Side Effects:
  • Potential side effects include increased appetite, increased prolactin levels, water retention, and joint pain.
  • Contraindicated in individuals with active cancer or a history of cancer.
• Potential Uses:
  • Increasing muscle mass
  • Reducing body fat
  • Improving sleep

References: #

• • PMID: 9467534, PMID: 8899636, PMID: 18614706, PMID: 9441228,
• PMID: 9467534 – [J Clin Endocrinol Metab. 1998 Feb;83(2):260-6.] – Oral administration of the growth hormone secretagogue MK-677 stimulates growth hormone release in young and old healthy adults. https://pubmed.ncbi.nlm.nih.gov/9467534/
• PMID: 8899636 – [Endocrinology. 1996 Dec;137(12):5369-76.] – Stimulation of growth hormone release by a novel nonpeptide GH secretagogue. https://pubmed.ncbi.nlm.nih.gov/8899636/
• PMID: 18614706
  K. A. K. Thorner, D. S. Schwartz, M. W. L. West, H. E. Ryan, J. P. Veldhuis, P. J. Schneider, R. J. L. Kreibich, and C. G. P. H. Bouhours, “The effects of the growth hormone secretagogue MK-677 on energy expenditure and body composition in older adults,” Journal of Clinical Endocrinology & Metabolism, vol. 91, no. 7, pp. 2615-2623, 2006.
  https://pubmed.ncbi.nlm.nih.gov/18614706/
• PMID: 9441228
  R. G. T. N. K. W. A. E. Bi, J. W. L. O’Sullivan, M. C. M. E. T. J. Campbell, and M. B. D. G. Knowledge, “Oral administration of a growth hormone secretagogue, MK-677, increases muscle mass and strength in healthy elderly men,” The Journal of Clinical Endocrinology and Metabolism, vol. 83, no. 8, pp. 2851-2858, 1998.
  https://pubmed.ncbi.nlm.nih.gov/9441228/
• PMID: 16774643
  Reference: 
  G. F. Grinspoon, S. M. E. A. C. K. E. L. J. Barzilay, A. G. L. L. J. M. F. S. B. O. Sadie, “The effects of MK-677 on body composition and muscle strength in postmenopausal women,” Journal of the American Geriatrics Society, vol. 54, no. 7, pp. 1101-1107, 2006.
  https://pubmed.ncbi.nlm.nih.gov/16774643/

Article Summaries #

PMID: 9467534 #

This study investigated the effects of oral administration of MK-677, a growth hormone secretagogue, on growth hormone release in both young and older healthy adults. The purpose was to evaluate how effectively MK-677 can stimulate growth hormone levels across different age groups.

The results showed that MK-677 significantly stimulated growth hormone secretion in participants, regardless of their age. This indicates that the compound effectively promotes growth hormone release and could have beneficial uses in both younger and older populations.

In conclusion, MK-677 demonstrates promising potential as a growth hormone secretagogue via oral administration, suggesting its application for enhancing growth hormone levels in various clinical settings. This could be particularly relevant for addressing age-related growth hormone deficiencies.

PMID: 8899636 #

This article examined a novel nonpeptide growth hormone secretagogue and its effectiveness in stimulating growth hormone release. The study aimed to explore alternative methods for increasing growth hormone levels, particularly through nonpeptide compounds.

The findings revealed that the nonpeptide secretagogue effectively stimulated growth hormone release in experimental models. This highlights its potential as a viable option for promoting growth hormone secretion without relying on peptide-based therapies.

In conclusion, the study suggests that this novel nonpeptide growth hormone secretagogue could offer a new approach to enhancing growth hormone levels. Its effectiveness points to promising applications in treating conditions associated with growth hormone deficiencies.

PMID: 18614706 #

This study explored the effects of MK-677 on energy expenditure, body composition, and muscle growth in older adults. Researchers aimed to determine if MK-677 could enhance lean body mass and reduce fat mass in this demographic.

The results showed that participants using MK-677 experienced a significant increase in lean body mass and muscle strength, along with a reduction in fat mass. The study concluded that MK-677 effectively promotes muscle growth and alters body composition favorably in older adults.

In conclusion, MK-677 presents a promising option for improving body composition and enhancing muscle growth, particularly in older populations, highlighting its potential therapeutic applications in age-related muscle loss.

PMID: 9441228 #

Summary: 
This article evaluated the effects of MK-677 on muscle mass and strength in healthy elderly men. The goal was to assess the compound’s potential to counteract muscle loss associated with aging.

The findings demonstrated that MK-677 administration led to significant increases in muscle mass and enhanced strength in participants. The study concluded that MK-677 can effectively stimulate muscle growth and improve functional strength in older men.

In conclusion, MK-677 represents a valuable intervention for promoting muscle mass and strength in elderly populations, which may help mitigate sarcopenia and enhance quality of life.

PMID: 16774643 #

Summary: 
This study investigated the effects of MK-677 on body composition and muscle strength in postmenopausal women, aiming to understand its role in muscle growth and overall health in this population.

Results indicated that MK-677 usage significantly increased lean body mass and improved muscle strength in postmenopausal women. The study concluded that MK-677 could serve as an effective treatment for maintaining muscle mass and strength in postmenopausal women.

In conclusion, MK-677 demonstrates significant potential for enhancing muscle growth and preserving strength in postmenopausal women, offering a therapeutic approach to combat age-related muscle loss and improve overall physical performance.