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MK-677 (Ibutamoren)
25mg/ml x 30ml INFORMATION


MK 677, also known as Ibutamoren, Oratrope, or Nutrobal MK 677 (molecular weight 528.662), is a ghrelin agonist that acts on the human pituitary gland as a human growth hormone secretagogue and is sometimes classified along with selective androgen receptor modulators (SARMs). It differs from Ghrelin itself in that it is not a peptide but rather a spiropiperidine. Since it can cross the blood-brain barrier, MK-677 functions as a neuropeptide in the central nervous system. It is a very powerful hormone and it is not uncommon to find Ibutamoren and SARMs for sale in the same catalog. Human data shows that MK-677 has an advantage over compounds like GHRP-6 and GHRP-2 in that it elevates IGF-1 levels for 24 hours after a single dose without inhibiting natural pulsatile growth hormone release. Since it does not exert its effect via androgen receptor, it is believed that MK677 may improve body composition without negatively impacting endogenous androgen secretion like Testosterone and other anabolic compounds. Some data also suggests that MK677 may have synergistic effects when combined with growth hormone releasing peptides like Tesamorelin or Ipamorelin.


MK-677 Mechanism of Action

When administered orally, MK 677 Ibutamoren mimics the action of the hunger hormone ghrelin and, by doing so, increases growth hormones (GHs) in the body. It is powerfully effective in boosting levels of insulin-like growth factor 1 (IGF-1). Unlike growth hormone and most GH increasing peptides, Ibutamoren is orally bioavailable so it does not require injection for proper absorption.  Sports Technology Labs is the best place to buy MK-677 for sale on the internet due to their verified high purity, fast shipping, customer support, and secure payment processing.

MK-677 has displayed multiple effects in vitro, including:

  • Increase in GH levels

  • Increase in muscle mass and lean body mass

  • Reduced body fat

  • Increase in bone density

  • Faster muscle growth

  • Improved immune function

  • Improved REM sleep

  • Increased appetite

  • Reversal of growth hormone deficiency


Studies Involving MK 677

Medical studies conducted in the last decade have shown significant potential for MK 677 to encourage REM sleep, increase GH levels, and lean muscle mass. Several studies and clinical trials have been conducted that suggest MK-677 holds enormous promise as a drug that could enhance human health and potentially aid in the battle against frailty in the elderly by mitigating symptoms of the natural decline of growth factors that comes with aging, also known as somatopause [6]. Studies have been conducted on both young males (age 19-49) as well as men and women between the ages of 60 and 81.

  • One study found that MK-677 administration increased IGF-I and IGF-binding protein-3 (IGFBP-3) levels, and potentially could be used to counter somatotropic deficiency [1] and build muscle.

  • Another study found that MK-677 increased bone turnover, bone mineral density, muscle mass, and osteoblast activity in older adults and improved body composition [2]

  • A human study on MK 677 and sleep quality revealed a significant decrease in REM latency and a 50% increase REM sleep in older adults, as well as a 50% increase in stage 4 sleep and a 20% increase in REM sleep in young adults with the administration of MK677 [10]. Stage 4 is the sleep stage in which the most tissue repair occurs so this may be of significant interest in studies aimed at improving recovery and neurological function.

  • A placebo-controlled study involving both young and older adults found improvements in sleep quality when compared to the placebo after three separate seven day administration trials.

  • A randomized controlled trial in healthy older adults found that daily administration of 25mg per day MK677 improved body composition, bone mineral density, and cholesterol levels while improving appetite for several months.

  • A double-blind randomized controlled trial in healthy volunteers ages 24 – 39 on a calorie restricted diet found that MK677 significantly improved nitrogen retention even in an environment of negative nitrogen balance. This means that subjects maintained muscle mass even with was considered less than sufficient protein consumption. This may be of significant interest in the treatment of patients on parenteral nutrition or restricted to IV feeding [8].

  • Animal data suggests that MK677 may be effective in reducing neuroinflammation, neurodegeneration, synapse loss, and slowing the early stages of beta amyloid build up in the brain, a significant contributory factors for dementia and Alzheimer’s Disease [9]. The implications are that MK 677 may function as a preventative agent, not a curative agent, even in cases of genetic predisposition. More human data is necessary to confirm this.


Potential Side Effects of Ibutamoren

However, it must be emphasized that MK-677 has not been approved by the Food and Drug Administration (FDA) for human consumption and efficacy. The severity of documented side effects like water retention, angiogenesis, and changes in blood pressure and blood sugar are still being determined. Potential drug interractions are also unknown at this time so caution is critical with this compound. Since it has a very long half life, there is a some concern that sustained administration of MK-677 can overstimulate or desensitize the ghrelin receptor in the human brain. Perhaps the most immediately noticeable side effect of Ibutamoren at this time is a significant increase in appetite and hunger [3, 4].

It is in the preclinical stages of investigation for GH-deficiency [5] and should be used for research purposes only, not for hobbyists building muscle. At this time the best MK 0677 dose and general information about ideal MK677 dosage has not yet been established. Further important research into MK-677 will be performed in the years to come.


MK-677 FAQs

Can MK-677 raise growth hormone and IGF-1 to the same extent as therapeutic treatment with HGH?

  • Studies have demonstrated the ability of MK 677 (aka Nutrobal) to raise endogenous levels of HGH and IGF-1 [1].

Can MK 677 suppress your body’s natural GH production?

  • There is presently no evidence that MK677 compromises the body’s natural release of GH long term. More information may be available in the future.

Does MK 677 suppress testosterone?

  • MK-677 does not act on the feedback loop for testosterone in the human body and is not expected to suppress natural testosterone levels.


 Abuse Warning

MK677 is an investigational compound still awaiting FDA approval and is not a dietary supplement. At Mass to Brass LLC, not medical doctors, and our expertise is sourcing and quality control. Where we do not encourage or condone consumer use of SARMs products, they are for research purposes only. Anecdotal reports online indicate MK 677 dosage of 12.5mg and 25mg per day used by many individuals. An MK677 dose of 40mg per day has even been reported by several individuals in online forums. These dosages may not match those used in carefully designed medical research protocols and may pose a serious risk of adverse effects in users.

We consider the duplication of anecdotal protocols online to be a risky practice. SARMs should only be used under the supervision and direction of a medical doctor or designated research authority. We strongly discourage the use of SARMs for performance enhancement in sports and bodybuilding, and warn against “bro science” and peer consensus when making decisions about human health.



  1. G Copinschi, A Van Onderbergen, M L’Hermite-Balériaux, C M Mendel, A Caufriez, R Leproult, J A Bolognese, M De Smet, M O Thorner, E Van Cauter, Effects of a 7-day treatment with a novel, orally active, GH secretagogue, MK-677, on 24-hour GH profiles, IGF 1, and adrenocortical function in normal young men, The Journal of Clinical Endocrinology & Metabolism, Volume 81, Issue 8, 1 August 1996, Pages 2776–2782,

  2. Murphy MG, Bach MA, Plotkin D, Bolognese J, Ng J, Krupa D, et al. 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;14:1182–1188

  3. 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 GH 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.

  4. Meyer RM, Burgos-Robles A, Liu E, Correia SS, Goosens KA. A ghrelin-growth hormone axis drives stress-induced vulnerability to enhanced fear. Mol Psychiatry. 2014 Dec;19(12):1284-94. doi: 10.1038/mp.2013.135. Epub 2013 Oct 15. PMID: 24126924; PMCID: PMC3988273.

  5. Chapman IM, Pescovitz OH, Murphy G, Treep T, Cerchio KA, Krupa D, Gertz B, Polvino WJ, Skiles EH, Pezzoli SS, Thorner MO. Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimulates the GH/insulin-like growth factor-I axis in selected GH-deficient adults. J Clin Endocrinol Metab. 1997 Oct;82(10):3455-63. doi: 10.1210/jcem.82.10.4297. PMID: 9329386.

  6. Smith RG, Sun Y, Jiang H, Albarran-Zeckler R, Timchenko N. Ghrelin receptor (GHS-R1A) agonists show potential as interventive agents during aging. Ann N Y Acad Sci. 2007 Nov;1119:147-64. doi: 10.1196/annals.1404.023. PMID: 18056963.

  7. Nass R, Pezzoli SS, Oliveri MC, Patrie JT, Harrell FE Jr, Clasey JL, Heymsfield SB, Bach MA, Vance ML, Thorner MO. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008 Nov 4;149(9):601-11. doi: 10.7326/0003-4819-149-9-200811040-00003. PMID: 18981485; PMCID: PMC2757071.

  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. Jeong YO, Shin SJ, Park JY, Ku BK, Song JS, Kim JJ, Jeon SG, Lee SM, Moon M. MK-0677, a Ghrelin Agonist, Alleviates Amyloid Beta-Related Pathology in 5XFAD Mice, an Animal Model of Alzheimer’s Disease. Int J Mol Sci. 2018 Jun 18;19(6):1800. doi: 10.3390/ijms19061800. PMID: 29912176; PMCID: PMC6032329.

  10. 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.

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