Titus Thorne

Last Updated March 14, 2023

Titus Thorne

 March 14, 2023

Curious about MK-677 for bodybuilding?

Then you're in the right place! This guide has you covered.

There is significant research interest in using MK-677 for bodybuilding, although the compound has not been subject to a large-scale study to this end.

In this guide, we outline the known and potential effects and impact of this GH secretagogue in the context of bodybuilding. Researchers will find a complete history of MK-677 and a review of available research into how it affects muscle building and healing in test subjects.

Buy MK-677 from the #1 online Peptides vendor in the world...

Disclaimer: Peptides.org contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. Peptides.org makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. Peptides.org makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What is MK-677?

MK-677 is a small-molecule drug also known as ibutamoren mesylateone. It is an orally active, selective agonist of the ghrelin receptor and its principal effect is to increase the secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) [1].

MK-677 behaves similarly to growth hormone-releasing peptide 6 (GHRP-6), the first growth hormone secretagogue (GHS) to have been synthesized—back in the 1970s. It mimics the endogenous hormone ghrelin in terms of its growth hormone-stimulating effect [2].

At the time of writing, MK-677 is classified by the U.S. Food and Drug Administration as an “Investigational New Drug” and does not have any recognized clinical use in the United States. This highest developmental phase yet reached by MK-677 is a Phase II clinical trial for somatropin deficiency, sponsored by Lumos Pharma/Merck and currently ongoing [3].

MK-677 is available as a research chemical and may be purchased by researchers interested in investigating its effects. In the following section, we outline the main benefits observed in past trials and studies involving MK-677.

MK-677 For Bodybuilding

Benefits of MK-677

Researchers interested in the potential benefits of MK-677 for bodybuilding will note no studies or clinical trials to date have explicitly focused on this research goal. Further, relatively little is known about MK-677’s effects on healthy, non-elderly individuals [4].

Instead, the available research literature shows that MK-677 has been studied in a series of smaller trials of short duration, with the longer trials involving elderly patients.

While the results of these trials cannot be extrapolated to healthy individuals, they suggest that MK-677 may offer the following benefits to researchers interested in examining the potential use of MK-677 for bodybuilding.

MK-677 Raises GH and IGF-1 Levels

MK-677 has a pronounced effect on growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels, which has led to its now being evaluated as a potential treatment for GH deficiency in children [3].

Unlike recombinant human GH (rhGH), which must be injected, MK-677 can be orally administered once daily, meaning that adverse reactions related to injections will not be a concern to researchers working with this compound [5].

Researchers have evaluated MK-677 as a potential treatment for somatotropin deficiency and found that it increases the secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) in adult patients [6]. While this research has not focused on bodybuilding, they do serve as a useful point of reference for MK-677 bodybuilding researchers, given the effects of GH and IGF-1 on cell growth, metabolism, and physical capacity.

MK-677 and Body Composition

Since MK-677 can raise serum concentrations of GH and IGF-1, the compound may be used to alter body composition in subjects, such as by increasing lean muscle mass and reducing body fat. This brings us to the core of why researchers may want to investigate MK-677 for bodybuilding.

For example, a 1998 study involving 24 obese males found that those who received 25 mg/day of MK-677 for eight weeks experienced increases in GH secretion, fat-free mass, and energy expenditure [7].

Additionally, subjects who undergo periods of caloric restriction may suffer from diet-induced protein catabolism. In another 1998 study, a group of eight healthy volunteers undertook a diet (18 kcal/kg.day) for two 14-day periods. Researchers found that those in the MK-677 treatment group experienced improved nitrogen balance compared with placebo [8].

This research suggests that MK-677 may help preserve fat-free mass while dieting, which is of interest to researchers investigating MK-677 for bodybuilding. Further studies are needed to evaluate whether MK-677 offers similar benefits in non-obese individuals or whether a higher dose of MK-677 can help reduce body fat.

MK-677 and Sleep Quality

Sleep is an essential part of the recovery cycle and adequate rest significantly impacts strength, metabolism, and overall health.

Researchers interested in researching MK-677 for bodybuilding may note that a 1998 study by Copinschi et al. found that MK-677 improved the quality and duration of sleep in male test subjects. This small-scale study found that research subjects who were administered 25mg MK-677 daily experienced a 50% increase in Stage 4 sleep and a 20% increase in REM (rapid eye movement) sleep [9]. The positive impact of MK-677 therapy on sleep suggests that further research in this area may be warranted.

MK-677 Dosage Guide

While there is strong research interest in the administration of MK-677 to improve physical performance and body composition, there are no published guidelines regarding MK-677 dosage to this end.

Since MK-677 is a research chemical that lacks prescribing guidelines, researchers wishing to investigate MK-677 for bodybuilding should consult the relevant literature to see how this compound has been administered in past trials [7, 8, 9].

Sample Protocol: MK-677 for Bodybuilding

Nonetheless, the available research indicates that a sample MK-677 protocol for bodybuilding, with a focus on lean muscle mass growth and preservation, would be as follows:

Daily Dosage

12.5mg-25mg, depending on factors like the subject’s body weight and whether other compounds are administered.


For subjects administered 25mg daily, administer one capsule in the morning and one in the evening.

 Study Duration

Four to twelve weeks, as needed to observe the effect of MK-677 on the subject’s body composition. Monitor the subject for insulin resistance, as a precautionary measure.


Most vendors sell 12.5mg MK-677 capsules, including our go-to vendor presented below. One 60 capsule bottle represents a 1-2 month supply of MK-677, based on this protocol.

MK-677 For Bodybuilding

MK-677 For Bodybuilding | The Basics

Researchers new to investigating MK-677 for bodybuilding may note that this orally-available growth hormone secretagogue has been the subject of limited research.

Consulting past studies can illuminate similarities between the way that other researchers have explored this peptide. Here is a review of the basics.

MK-677 For Beginners

One of the best MK-677 studies for beginning researchers to consult is the MK-677 sleep study by Copinschi et al. [9]. This small-scale study involved just eight research subjects and lasted for three 7-day periods, making it one of the shortest MK-677 studies completed to date. Participants were administered 5-25mg MK-677 daily at bedtime, presumably to coincide with the peak in natural levels of hGH.

As there is still no consensus on the impact of MK-677 on muscle recovery, this highlights one potential direction for future research. Beginner researchers may consult the dosage and duration of this study when designing their MK-677 research.

Legal Status

Mk-677 is currently classified as a research chemical. This means that it has no formally recognized clinical use and has not been reviewed or approved by the US Food and Drug Administration. That said, MK-677 is available for sale to qualified researchers and laboratory professionals.

MK-677 is currently the subject of at least one large-scale clinical trial, the Lumos Pharma Phase II trial, which has the goal of evaluating MK-677 as a potential treatment for GH-deficient children and non-alcoholic fatty liver disease in adults [3].

Muscle Growth

While researchers are actively investigating MK-677 for muscle growth, there is a lack of long-term research involving healthy (non-GH-deficient) test subjects for this purpose.

To date, MK-677 has been shown to raise GH and IGF-1 levels, while specifically increasing fat-free mass in obese test subjects [4, 7]. This research indicates that further research into MK-677’s effect on muscle growth may be warranted.


Past research involving MK-677 has shown that it may have a positive impact on sleep, which is relevant to researchers investigating MK-677 for healing. As noted earlier, the sleep study by Copinschi et al. found that MK-677 caused a 50% increase in the duration of stage IV sleep and a 20% increase in rapid eye movement (REM) sleep when administered to test subjects at doses of up to 25mg for two seven-day periods [9].

Three other clinical studies investigated MK-677’s effect on markers of bone turnover in functionally impaired elderly patients. These studies, which lasted two-nine weeks and involved 187 elderly test subjects, found that MK-677 increased mean serum osteocalcin by 29.4% and BSAP by 10.4% compared with placebo [10].

While these findings cannot be extrapolated to non-elderly populations, they do show that MK-677 offers potential benefits for healing that warrant further investigation.

Where to Buy MK-677 Online? | 2023 Guide

Researchers interested in exploring MK-677 for bodybuilding can readily find this research chemical for sale online. The main problem is identifying a vendor that is reliable, trustworthy, and able to deliver on quality.

To assist researchers, our team has placed a number of test orders with various vendors and rated them according to their prices, speed of delivery, customer service, and quality. In our opinion, Peptide Sciences is the #1 peptide vendor online.

Here are a few reasons why we rated them so highly:

Fair MK-677 Prices

Peptide Sciences sells bottles of 60 12.5mg MK-677 capsules for $125 each. Researchers placing a bulk order of three or more bottles can save 8% from this price, lowering the cost per bottle to just $115.

Independent, Third-Party Testing

Many vendors claim to offer research-grade MK-677, but Peptide Sciences is one of the few vendors that submits its MK-677 for rigorous testing to an independent, third-party lab. It then posts the results on its website, offering a high level of transparency. Researchers can view the Certificate of Analysis (COA) and results of High Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS) tests on the Peptide Sciences website before placing an order.

Fast Domestic and International Shipping

Orders to the US take as little as 2-3 days while worldwide orders typically take 7-10 days. Shipping charges are waived on all orders over $200 within the United States.

Range of Convenient Payment Options

Researchers can pay with Apple Cash, Cash App, Zelle, credit cards (via Mesh Payments), Flex payment, and electronic checks.

Reasonable Refund Policy

Peptide Sciences strives to ensure that customers are 100% satisfied with the quality of its MK-677 capsules and, in the unlikely event of an order going missing or arriving damaged, may be contacted via email for assistance.

Buy MK-677 from the #1 online Peptides vendor in the world...

MK-677 and Bodybuilding | Verdict

Researchers interested in exploring the potential of MK-677 for bodybuilding will note that there are only a handful of small-scale studies involving healthy individuals to draw upon.

Data from these studies indicates that MK-677 can reverse diet-induced catabolism, increase levels of fat-free mass, and improve the quality and duration of sleep. These findings are encouraging and indicate that further research may be warranted.

While there is currently strong interest in MK-677 for bodybuilding, there are no official guidelines for dosing the compound to this end. The limited, short-term MK-677 studies conducted to date reveal little about this research chemical’s long-term effects.

Looking to source MK-677? Just click here. 


  1. Patchett AA, Nargund RP, Tata JR, Chen MH, Barakat KJ, Johnston DB, Cheng K, Chan WW, Butler B, Hickey G, et al. Design and biological activities of L-163,191 (MK-0677): a potent, orally active growth hormone secretagogue. Proc Natl Acad Sci U S A. 1995 Jul 18;92(15):7001-5. doi: 10.1073/pnas.92.15.7001. PMID: 7624358; PMCID: PMC41459.
  2. Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1998 Dec;54(12):1316-29. doi: 10.1007/s000180050257. PMID: 9893708.
  3. Ibutamoren – Lumos Pharma/Merck – AdisInsight. (2022). Retrieved 6 January 2022, from https://adisinsight.springer.com/drugs/800007434
  4. Sigalos JT, Pastuszak AW. The Safety and Efficacy of Growth Hormone Secretagogues. Sex Med Rev. 2018 Jan;6(1):45-53. doi: 10.1016/j.sxmr.2017.02.004. Epub 2017 Apr 8. PMID: 28400207; PMCID: PMC5632578.
  5. Smith RG. Development of growth hormone secretagogues. Endocr Rev. 2005 May;26(3):346-60. doi: 10.1210/er.2004-0019. Epub 2005 Apr 6. PMID: 15814848.
  6. Codner E, Cassorla F, Tiulpakov AN, Mericq MV, Avila A, Pescovitz OH, Svensson J, Cerchio K, Krupa D, Gertz BJ, Murphy G. Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient children. Clin Pharmacol Ther. 2001 Jul;70(1):91-8. doi: 10.1067/mcp.2001.116514. PMID: 11452249.
  7. Svensson J, Lönn L, Jansson JO, Murphy G, Wyss D, Krupa D, Cerchio K, Polvino W, Gertz B, Boseaus I, Sjöström L, Bengtsson BA. Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure. J Clin Endocrinol Metab. 1998 Feb;83(2):362-9. doi: 10.1210/jcem.83.2.4539. PMID: 9467542.
  8. Murphy MG, Plunkett LM, Gertz BJ, He W, Wittreich J, Polvino WM, Clemmons DR. MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab. 1998 Feb;83(2):320-5. doi: 10.1210/jcem.83.2.4551. PMID: 9467534.
  9. Copinschi G, Leproult R, Van Onderbergen A, Caufriez A, Cole KY, Schilling LM, Mendel CM, De Lepeleire I, Bolognese JA, Van Cauter E. Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man. Neuroendocrinology. 1997 Oct;66(4):278-86. doi: 10.1159/000127249. PMID: 9349662.
  10. Murphy MG, Bach MA, Plotkin D, Bolognese J, Ng J, Krupa D, Cerchio K, Gertz BJ. Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. The MK-677 Study Group. J Bone Miner Res. 1999 Jul;14(7):1182-8. doi: 10.1359/jbmr.1999.14.7.1182. PMID: 10404019.

Table of Contents
    Add a header to begin generating the table of contents