MK-677 Pill Reverses Muscle Breakdown From Calorie Restriction

Oral MK-677 reversed the protein loss caused by calorie restriction in healthy volunteers, with effects comparable to growth hormone injections.

Murphy, M G et al.·The Journal of clinical endocrinology and metabolism·1998·Strong EvidenceRCT
RPEP-00480RCTStrong Evidence1998RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
RCT
Evidence
Strong Evidence
Sample
Not reported

What This Study Found

MK-677 at 25 mg daily reversed diet-induced nitrogen wasting in healthy volunteers, increasing IGF-1 by 40% and producing sustained anabolic effects comparable to GH injections.

Key Numbers

How They Did This

Double-blind, randomized, placebo-controlled, two-period crossover study in 8 healthy volunteers (ages 24-39). Calorie restriction was used to induce negative nitrogen balance, then MK-677 or placebo was administered. Nitrogen balance, GH, IGF-1, and cortisol were measured.

Why This Research Matters

Muscle wasting from illness, aging, or calorie restriction is a major health problem. An oral medication that prevents protein loss could help hospitalized patients, the elderly, and anyone recovering from illness maintain muscle mass.

The Bigger Picture

Most GH-boosting treatments require injections, limiting their practical use. An effective oral GH secretagogue that preserves muscle during calorie restriction could transform treatment of muscle wasting conditions, from post-surgical recovery to age-related sarcopenia.

What This Study Doesn't Tell Us

Small sample size (8 volunteers). Short-term study in healthy young adults. Effects in actual catabolic patients (elderly, critically ill) may differ. Long-term safety not assessed.

Questions This Raises

  • ?Does MK-677 prevent muscle loss in elderly patients or those with chronic illness?
  • ?What are the long-term effects of sustained IGF-1 elevation from MK-677?
  • ?Could MK-677 reduce hospital length of stay by preventing catabolic muscle loss?

Trust & Context

Key Stat:
40% IGF-1 increase Oral MK-677 at 25 mg daily increased IGF-1 by approximately 40% and reversed nitrogen wasting in calorie-restricted healthy volunteers
Evidence Grade:
Strong evidence from a well-designed double-blind, placebo-controlled crossover RCT, though limited by small sample size and short duration.
Study Age:
Published in 1998. MK-677 (ibutamoren) has since been studied extensively for muscle wasting, aging, and growth hormone deficiency.
Original Title:
MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.
Published In:
The Journal of clinical endocrinology and metabolism, 83(2), 320-5 (1998)
Database ID:
RPEP-00480

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What is MK-677?

MK-677 (ibutamoren) is an oral compound that mimics the GH-releasing peptide GHRP. Unlike most growth hormone therapies that require injections, MK-677 is taken as a pill and stimulates the body's own GH production.

Can MK-677 prevent muscle loss?

This study shows it reversed protein breakdown during calorie restriction in healthy adults. It's being studied for preventing muscle loss in aging, illness, and other catabolic states, though it's not approved for these uses.

Read More on RethinkPeptides

Cite This Study

RPEP-00480·https://rethinkpeptides.com/research/RPEP-00480

APA

Murphy, M G; Plunkett, L M; Gertz, B J; He, W; Wittreich, J; Polvino, W M; Clemmons, D R. (1998). MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.. The Journal of clinical endocrinology and metabolism, 83(2), 320-5.

MLA

Murphy, M G, et al. "MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.." The Journal of clinical endocrinology and metabolism, 1998.

RethinkPeptides

RethinkPeptides Research Database. "MK-677, an orally active growth hormone secretagogue, revers..." RPEP-00480. Retrieved from https://rethinkpeptides.com/research/murphy-1998-mk677-an-orally-active

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.