MK-677 (ibutamoren)

What it is

MK-677, also called ibutamoren, is a lab-made drug taken by mouth. It binds to and switches on the receptor for the hormone ghrelin on growth hormone-making cells in the pituitary gland and on nerve cells in the hypothalamus, so the body releases more of its own growth hormone¹. It also increases appetite¹². More growth hormone in turn raises insulin-like growth factor 1 (IGF-1)¹⁶. It works through a different receptor from growth hormone-releasing hormone, whose lab-made copies include sermorelin and tesamorelin¹²¹⁶. It is not a peptide: FDA describes it as a non-peptide small molecule, though its structure contains serine and 2-aminoisobutyric acid, an amino acid not used to build proteins¹. It is grouped with peptides because it acts like them. Its Merck developers found it worked in the same way as GHRP-6, a growth hormone-releasing peptide⁴. FDA places it in one drug class, growth hormone secretagogues, that includes both peptides and non-peptides, and the anti-doping list names it beside ipamorelin¹¹². Sellers also offer it alongside injectable peptides⁵. Unlike those peptides, it works when swallowed: FDA cites a 1997 paper stating that a single dose is long-acting (24 hours) and active by mouth¹. The form nominated for compounding, and named in trial reports, is a salt, ibutamoren mesylate¹³¹⁶.

Merck researchers made MK-677, first coded L-163,191, in 1995 while looking for a growth hormone booster that works by mouth¹⁴. It was then tested in healthy older adults, obese men, older women with low bone density, and people with Alzheimer’s disease or a recent hip fracture^36781718. FDA’s 2024 review says development was discontinued in 1999, yet ClinicalTrials.gov lists Merck-sponsored trials in Alzheimer’s disease (October 2003 to January 2006) and after hip fracture (September 2005 to August 2007, terminated early)¹¹⁹²⁰. Lumos Pharma later licensed it and renamed it LUM-201 for children with growth hormone deficiency¹²¹. A placebo-controlled final-stage (Phase 3) trial in such children lists a start date of 20 May 2026, and a trial pairing it with oral semaglutide in older adults with obesity was listed on 10 August 2026 as not yet recruiting, with a planned start of 15 February 2027²²²³.

Benefits: what the research shows

Most human trials gave 25 mg by mouth once a day, and most enrolled older adults. In 32 healthy adults aged 64 to 81, 25 mg a day nearly doubled average 24-hour growth hormone levels after 2 weeks and raised IGF-1 into the normal range for young adults by 4 weeks, while fasting blood sugar rose from 5.4 to 6.8 mmol/L⁶. The longest trial randomized 71 healthy adults aged 60 to 81 to 25 mg a day or placebo, and 65 completed the first year. Fat-free mass (lean mass, which includes muscle and body water) rose by 1.1 kg on the drug and fell by 0.5 kg on placebo, and weight rose by 2.7 kg vs 0.8 kg. Limb fat rose more on the drug, but deep belly fat and total fat did not differ. Strength and physical function did not change, although the trial was too small to test function well². Fasting blood sugar rose by 0.3 mmol/L (5 mg/dL), insulin sensitivity fell, the stress hormone cortisol rose and LDL cholesterol fell slightly². In 24 obese men, 8 weeks of 25 mg raised IGF-1 by about 40% and increased fat-free mass, but total fat and deep belly fat did not change, and a glucose tolerance test worsened at 2 and 8 weeks¹⁷. In 8 healthy young adults on a low-calorie diet, 7 days of 25 mg turned the diet’s protein loss into a small gain (nitrogen balance +0.31 g/day vs -1.48 g/day on placebo)²⁵. In a small sleep study, 25 mg at bedtime for 7 days increased deep (stage IV) sleep by about 50% and REM sleep by more than 20% in 8 young adults compared with placebo; in 6 older adults, REM sleep rose by nearly 50% compared with their own baseline²⁶. Trials aimed at diseases were mostly negative. In 563 people with mild to moderate Alzheimer’s disease, a year of 25 mg raised IGF-1 by about 73% but did not slow the disease on any measure⁷. After hip fracture, a 6-month trial in 161 older adults found no significant gain in function⁸. A second, 24-week trial in 123 patients found a small gain in gait speed but none in stair-climbing power or most other measures, and it was stopped early over a heart failure signal: FDA’s review counts congestive heart failure in 4 patients (6.5%) on the drug vs 1 (1.7%) on placebo¹³. In 292 older women with low hip bone density, the drug raised markers of bone turnover; combined with the osteoporosis drug alendronate, it raised bone density at the femoral neck, part of the hip, by 4.2% vs 2.5% with alendronate alone, but not at the spine, total hip or whole body¹⁸. In 22 people on hemodialysis, each given 25 mg a day for 1 month and placebo for another month, IGF-1 rose 65% more on the drug than on placebo, with no serious side effects attributed to it²⁷. In an open-label pilot study in adults with fatty liver disease, 6 months of 25 mg did not lower liver fat; only 7 of 12 finished, and the results were posted on 6 January 2026²⁸. In 9 young men with severe growth hormone deficiency, 4 days of 10 or 50 mg raised IGF-1 by 52% and 79%²⁹, and in 18 children with growth hormone deficiency, 7 to 8 days of treatment raised IGF-1 in some of them¹⁶. In a randomized trial whose results were posted on 17 June 2026, 82 children with growth hormone deficiency who had responded to a test dose took LUM-201 by mouth or daily growth hormone injections, and growth was compared after 6 months. In the registry’s per-protocol analysis, their growth rates, expressed per year, were 6.8 to 8.2 cm on LUM-201 vs 10.6 cm on injections; 43 of the 62 children on LUM-201 did not complete the randomized phase, 39 of them after failing the growth-rate criteria or moving early to an extension study³⁰. A placebo-controlled trial in children is recruiting, with completion estimated for January 2028²². FDA’s 2024 review found ‘insufficient information’ to support its use for growth hormone deficiency, osteoporosis, hip fracture, sarcopenia (age-related muscle loss), obesity or Alzheimer’s disease¹. We found no controlled trial in young, healthy people who lift weights⁵¹⁵².

Key human studies

Doses studied

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

Half-life

No human value found; a single dose acts for about 24 hours¹FDA’s 2024 review found no human half-life data. It cites one 1996 trial for the drug’s ‘high oral bioavailability and its long duration of action’ and a 1997 paper stating that a single dose is long-acting (24 hours); in dogs, more than 60% of an oral dose reaches the blood¹. A dosing website’s figure of 4 to 6 hours cites no study⁴².

Routes

• By mouth as tablets, capsules or liquid (all human trials)
• Injection (a 64 mg/mL product was seen for sale by FDA; no human data found)

Every dose studied for MK-677 (ibutamoren), with sources →

Legal status

United States

Not approved for any use. FDA’s 2024 review found no FDA-approved product and no USP monograph, and ibutamoren is not part of any approved drug¹. In a warning letter of 19 December 2025, FDA said ibutamoren is excluded from the legal definition of a dietary supplement, because it was authorized for study as a new drug, substantial clinical studies of it were made public, and it was not sold as a supplement or food before that¹¹. On 23 September 2025 FDA advised consumers not to buy or use a growth supplement sold for children aged five and older, after its lab found ibutamoren that was not on the label⁹. In a warning letter of 12 December 2025 to an online seller of ‘MK-677 Ibutamoren’ and SARMs, FDA said that ‘for research use only’ statements did not change the fact that the products were intended as drugs for people, making them unapproved new drugs³⁴. It is not a federally controlled substance: the DEA schedules in 21 CFR Part 1308 (as of 25 September 2026) do not name it³⁵.

US pharmacies

Section 503A sets the rules for ordinary pharmacies that compound medicines for individual patients. Ibutamoren mesylate has been in Category 2 of FDA’s list of bulk substances nominated for 503A compounding since 29 September 2023, and it was still there in the list updated 14 May 2026¹⁰³¹. Category 2 means FDA has identified ‘significant safety risks’ pending further evaluation, and FDA says it would consider acting against a pharmacy that compounds with such a substance³². A 503A pharmacy may compound from bulk powder only if the ingredient has a USP monograph, is part of an FDA-approved drug or is on the 503A bulks list; ibutamoren meets none of these, so US pharmacies may not make it¹¹⁰³². FDA’s stated reason is ‘the potential for congestive heart failure in certain patients’, citing the hip-fracture trial that ‘was terminated early due to a potential safety signal of congestive heart failure’³¹. It has also been in Category 2 for outsourcing facilities under section 503B since 29 December 2022³¹. The nominations FDA reviewed proposed 10 and 25 mg oral products for growth hormone deficiency; one nominator later added hip fracture, sarcopenia, osteoporosis, Alzheimer’s disease, obesity and fibromyalgia¹. On 29 October 2024 FDA’s Pharmacy Compounding Advisory Committee (PCAC) voted 13 to 1 against adding it to the 503A bulks list: several members said the evidence did not support its efficacy and safety, several raised concerns about fluid retention, congestive heart failure and high blood sugar, and the one member in favor pointed to its extensive use and the data in children³⁶. On 15 April 2026, HHS Secretary Robert F. Kennedy Jr. posted that FDA would remove 12 peptides from Category 2 after their nominators withdrew them, and his list included ibutamoren mesylate³⁷. FDA’s own pages, checked on 5 October 2026, still list it in Category 2 and not among the withdrawn substances¹⁰³¹. It was not on the agenda of the July 2026 committee meeting, nor among the five substances FDA lists for the committee’s next meeting, to be held before the end of February 2027³⁸⁵⁰. Even leaving Category 2 would not by itself let pharmacies make it, because FDA’s interim policy shields only Category 1 substances³².

Other countries

Australia: ibutamoren is a Schedule 4 (prescription only) poison and is listed in Appendix D, clause 5, of the Poisons Standard in force from 1 October 2026, which covers poisons that must not be possessed without authority, such as a legal prescription; the index cross-references the names MK-677 and Nutrobal¹³. Canada: Health Canada says ibutamoren (MK-677) is not authorized for any use in Canada and that selling unauthorized health products is illegal. Its advisories list ibutamoren (MK-677) products seized from supplement stores in Alberta (listed in 2023), from online sellers in Quebec (listed in 2024 and 2025), from a Quebec distributor (listed on 9 July 2025) and from two stores in Maple Ridge, British Columbia (advisory of 24 December 2025)⁵³⁹. EU: FDA’s review found no product authorized by the European Medicines Agency; the European Commission granted ibutamoren mesylate orphan designation for growth hormone deficiency in June 2017¹. FDA’s review, citing a university report, also found no approved product in Canada, the UK, Ireland, Australia, New Zealand and several other countries¹. UK legal status beyond that: not verified.

Sport

Prohibited at all times, in and out of competition. The 2026 List names ‘ibutamoren (MK-677)’ among the growth hormone secretagogues under S2.2.4, a non-Specified class, alongside ipamorelin and macimorelin¹². The 2027 List, in force from 1 January 2027, keeps the same wording³³. In a case posted on 20 February 2026, the US Anti-Doping Agency gave a 46-year-old masters weightlifter a three-year ban after a urine sample collected at a competition on 5 December 2025 tested positive for ipamorelin and ibutamoren⁴⁰. A 2026 lab study found ibutamoren in a volunteer’s hair 4 weeks after a single 10 mg dose⁴¹.

MK-677 (ibutamoren) in the legal tracker →

Quality and the gray market

What testing finds

Finnrick, a service that publishes lab results for peptide samples, listed 11,999 tests of 34 products from 466 vendors as of 25 September 2026, and none were of MK-677¹⁴. In a 2017 US study of 44 products sold online as SARMs, 17 (39%) contained a different unapproved drug, such as ibutamoren, 11 (25%) contained substances not on the label, and only 18 (41%) held the labeled amount⁴³. Over 5 years, 14 laboratories in 13 countries belonging to the General European Official Medicines Control Laboratories Network (GEON) reported on 324 suspected illegal products bought as sport performance enhancers; ibutamoren was among the top five of 18 molecules found, and from the limited dose data reported, most samples appeared to contain active doses and some were overdosed¹⁵. FDA’s lab found ibutamoren, not listed on the label, in a children’s growth supplement in 2025⁹. In a 2024 case report, the 3 gym supplements a man had used contained MK-677, RAD-140 and cardarine between them, and all 3 also held testosterone, estradiol and growth hormone that were not disclosed⁴⁴. FDA’s 2024 review found that the nominators’ certificates of analysis reported 99.36% and 99.60% purity but included no tests for chiral purity, related impurities or residual solvents. It flagged possible methanesulfonate impurities, such as the mutagen ethyl methanesulfonate, from the final synthesis step¹.

How it is sold

FDA found websites selling ibutamoren as 10 to 25 mg capsules, 20 mg tablets, a 64 mg/mL injection, 1 g of powder and liquids of 17 to 67 mg/mL; some said their products were for research purposes only¹. It is marketed online to reverse aging and, wrongly, as a SARM for bodybuilding and weightlifting. Claimed benefits include more muscle, less body fat, stronger bones, better sleep, skin and thinking, faster healing and higher libido¹. An expert interviewed for a University of Maryland report cited by FDA described growth hormone secretagogues as ‘lifestyle medications’ for skin, hair or body, often used with testosterone, and one outsourcing facility reported compounding 25 mg capsules in 2019 and 2020¹. A seller that received an FDA warning letter on 12 December 2025 called it ‘MK677, also recognized as Ibutamoren, Oratrope, or Nutrobal’ and claimed it reduces body fat and increases muscle mass and bone density³⁴. The trials do not support all of these claims: lean mass rose but strength did not, body fat did not fall, Alzheimer’s disease did not slow, and bone density rose at only one hip site, and only when combined with an osteoporosis drug²⁷¹⁷¹⁸. In Canada, MK-677 products have been seized from supplement stores and online sellers, sometimes beside injectable peptides, SARMs and steroids⁵³⁹. On 30 September 2026 one online seller’s homepage listed MK-677 among its four ‘Most Popular’ products⁴⁵. A dosing website updated 25 August 2026 says users gain 1 to 2 kg of lean mass over 8 to 12 weeks while losing fat, that strength in major lifts rises 5% to 15%, and that improved insulin sensitivity is documented, without citing a trial⁴². In the first year of the 2-year trial in older adults, insulin sensitivity fell and strength did not change².

Side effects and risks

• Heart failure and blood pressure: a hip-fracture trial was stopped early after congestive heart failure in 4 patients (6.5%) on the drug vs 1 (1.7%) on placebo, and systolic blood pressure rose by 11.9 to 16.4 mmHg on the drug vs -2.3 to +2.3 mmHg on placebo¹³. Heart failure risk is the reason FDA gives for listing it as a significant safety risk in compounding³¹.
• Blood sugar: it raised fasting glucose and lowered insulin sensitivity in healthy older adults². In the Alzheimer’s trial, FDA’s review counts raised blood glucose in 15.4% on the drug vs 4.6% on placebo¹. One hip-fracture trial excluded people with diabetes or heart failure, so its results say nothing about them⁸.
• Fluid retention, pain and hunger: in the first year of the 2-year trial in older adults, FDA’s review counts swelling in 19 of 43 people on the drug vs 6 of 22 on placebo, muscle pain in 14 vs 2 and increased appetite in 29 vs 8¹. Side effects that led people to stop in trials included high blood sugar, high prolactin, raised liver enzymes and high blood pressure¹.
• Hormones and cancer: cortisol rose in older adults, and prolactin rose by 23%²⁶. FDA notes that older people with high IGF-1 levels have been observed to be at higher risk of disease or death, and that higher IGF-1 levels appeared to be associated with cancer risk at all ages¹.
• Liver: a 2025 case report describes raised liver enzymes after 2 months of MK-677 that returned to normal after stopping⁴⁶. As of 30 July 2026, FAERS held 5 liver injury reports naming MK-677 (3 appear to describe the same 25-year-old man), and all 5 also list SARMs⁴⁷.
• Animal and theoretical concerns: FDA’s review says the drug may have reinforcing properties that could contribute to addiction and that it caused low blood pressure in rats; in animal studies, another substance acting on the same receptor harmed development when given during pregnancy. FDA also notes that macimorelin, an approved drug of the same class, carries a risk of QT prolongation (a heart rhythm effect), and that there are too few data to rule out similar concerns¹.
• Product risks: products sold as SARMs often contain unlisted drugs, including ibutamoren⁴³, and supplements containing MK-677 have also held undisclosed hormones⁴⁴.
• Anti-doping and legal: banned in sport at all times; in February 2026 the US Anti-Doping Agency announced a three-year ban, counted from December 2025, for a masters weightlifter¹²⁴⁰. Having it without a prescription is illegal in Australia¹³.

Documented harms

• Sep 2011A 24-week hip-fracture trial was stopped early over a safety signal of congestive heart failure. FDA’s review counts heart failure in 4 patients (6.5%) on the drug vs 1 (1.7%) on placebo, and serious adverse events in 24% vs 13%, including one death on the drug from sepsis and pneumonia that was judged unrelated¹³.
• 30 Jul 2026FAERS, FDA’s adverse event database, held 14 reports naming ibutamoren or MK-677 as of its 30 July 2026 update. Only 3 name it alone: vomiting and stomach pain; malaise and numbness; and, in a 22-year-old man, abnormal behavior, vomiting blood, suicidal thoughts and withdrawal symptoms. The rest also list other products, often SARMs or testosterone, and include liver injury, blood clots and strokes. FAERS reports cannot show that a product caused an event⁴⁷.
• 23 Sep 2025FDA advised consumers not to buy or use a growth supplement sold for children aged five and older after its lab found ibutamoren that was not on the label. FDA listed possible effects including increased appetite, water retention, fatigue, muscle pain, changes in blood sugar control and possibly heart failure⁹. A warning letter to the company followed on 19 December 2025¹¹.
• Dec 2022A 25-year-old man took LGD-4033 (10 mg) and MK-677 (15 mg) daily for 5 weeks. His body mass rose 6.0% and his fat mass 15.4%; total testosterone fell 62.3%, HDL cholesterol fell 36.4%, LDL cholesterol rose 40% and the liver enzyme ALT rose 205%. Most values recovered after he stopped, but fat mass, bone area, total cholesterol and LDL did not⁴⁸.
• Aug 2024A 40-year-old man developed breast enlargement (gynecomastia) and low sex hormones after 6 months of gym supplements containing RAD-140, MK-677 and cardarine; lab tests also found undisclosed testosterone, estradiol and growth hormone in them. Both problems resolved after he stopped⁴⁴.
• 17 Jul 2025A healthy man in his early 30s developed raised liver enzymes after 2 months of MK-677; his liver tests returned to normal after he stopped⁴⁶.
• Mar 2026A 54-year-old man who had recently used MK-677 and RAD-140 for bodybuilding had a spontaneous rupture of the spleen and needed embolization and then removal of the spleen. The authors called a role for the compounds speculative and found signs of a possible vascular malformation⁴⁹.

Questions people ask

What is still unknown

• We found no controlled trial that tested MK-677 in young, healthy people who lift weights, the group it is mostly marketed to.
• FDA’s 2024 review found no human half-life data; the only human data it cites are statements that one dose acts for about 24 hours.
• Safety beyond 2 years, and in people with diabetes or heart disease, is unknown.
• HHS Secretary Kennedy’s 15 April 2026 list of 12 peptides leaving Category 2 named ibutamoren, but FDA’s pages still list it in Category 2; whether FDA will act on it is unknown.
• Results of the placebo-controlled LUM-201 trial in children (NCT06948214) are not expected before 2028.
• UK legal status was not verified, and EU status is known only through FDA’s review.
• Whether the registered Merck trials NCT00074529 and NCT00128115 are the published Alzheimer’s and hip-fracture trials was not confirmed; their enrollment counts (512 and 83) differ from the papers (563 and 123).
• The content and purity of gray-market MK-677 products are unknown; Finnrick, the public lab-testing service we checked, had no MK-677 results as of 25 September 2026.

Sources

1. 1FDA Briefing Document, Pharmacy Compounding Advisory Committee meeting of October 29, 2024: ibutamoren mesylate (FDA evaluation dated 3 July 2024) U.S. Food and Drug Administration, 3 Jul 2024. fda.gov
2. 2Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial Annals of Internal Medicine, 4 Nov 2008. pubmed.ncbi.nlm.nih.gov
3. 3MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study Archives of Gerontology and Geriatrics, Sep 2011. pubmed.ncbi.nlm.nih.gov
4. 4Design and biological activities of L-163,191 (MK-0677): a potent, orally active growth hormone secretagogue Proceedings of the National Academy of Sciences, 18 Jul 1995. pubmed.ncbi.nlm.nih.gov
5. 5Unauthorized health products seized from two stores in Maple Ridge, BC may pose serious health risks (RA-81404) Health Canada, 24 Dec 2025. recalls-rappels.canada.ca
6. 6Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects The Journal of Clinical Endocrinology & Metabolism, Dec 1996. pubmed.ncbi.nlm.nih.gov
7. 7Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial Neurology, 18 Nov 2008. pubmed.ncbi.nlm.nih.gov
8. 8The effects of MK-0677, an oral growth hormone secretagogue, in patients with hip fracture Journal of the American Geriatrics Society, Apr 2004. pubmed.ncbi.nlm.nih.gov
9. 9Agebox iKids Growth Day Formula may be harmful due to hidden ingredient U.S. Food and Drug Administration, 23 Sep 2025. fda.gov
10. 10Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
11. 11Warning letter to Agebox Inc. (MARCS-CMS 718252) U.S. Food and Drug Administration, 19 Dec 2025. fda.gov
12. 12World Anti-Doping Code International Standard: Prohibited List 2026 World Anti-Doping Agency, 24 Sep 2025. wada-ama.org
13. 13Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026 (F2026L01327) Federal Register of Legislation, Australian Government, 28 Sep 2026. legislation.gov.au
14. 14Finnrick public data summary (llms-full.txt, generated 25 September 2026) Finnrick, 25 Sep 2026. finnrick.com
15. 15SARMs, Metabolic Modulators and Growth Hormone Secretagogues in Suspected Illegal Medicines, Bought as Sport Performance Enhancers: A Retro- and Prospective Study Within the GEON Drug Testing and Analysis, Oct 2025. pubmed.ncbi.nlm.nih.gov
16. 16Effects 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 Clinical Pharmacology & Therapeutics, Jul 2001. pubmed.ncbi.nlm.nih.gov
17. 17Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure The Journal of Clinical Endocrinology & Metabolism, Feb 1998. pubmed.ncbi.nlm.nih.gov
18. 18Effect of alendronate and MK-677 (a growth hormone secretagogue), individually and in combination, on markers of bone turnover and bone mineral density in postmenopausal osteoporotic women The Journal of Clinical Endocrinology & Metabolism, Mar 2001. pubmed.ncbi.nlm.nih.gov
19. 19Study of MK0677 for the Treatment of Alzheimer’s Disease (0677-030)(COMPLETED) (NCT00074529) ClinicalTrials.gov, 24 Jul 2015. clinicaltrials.gov
20. 20Treatment of Sarcopenia in Post-Hip Fracture Patients (0677-032) (NCT00128115) ClinicalTrials.gov, 20 Jan 2016. clinicaltrials.gov
21. 21A GH Secretagogue Receptor Agonist (LUM-201) Elicits Greater GH Responses than Standard GH Secretagogues in Subjects of a Pediatric GH Deficiency Trial Hormone Research in Paediatrics, 2022. pubmed.ncbi.nlm.nih.gov
22. 22Phase 3 Study of LUM-201 in Children With Growth Hormone Deficiency (NCT06948214) ClinicalTrials.gov, 4 Sep 2026. clinicaltrials.gov
23. 23Evaluating the Efficacy and Safety of LUM-201 Plus Semaglutide Versus Semaglutide Plus Placebo in Older Obese Adults (NCT07754045) ClinicalTrials.gov, 10 Aug 2026. clinicaltrials.gov
24. 24Ibutamoren, PubChem compound summary (CID 178024) PubChem, U.S. National Library of Medicine, accessed 5 Oct 2026. pubchem.ncbi.nlm.nih.gov
25. 25MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism The Journal of Clinical Endocrinology & Metabolism, Feb 1998. pubmed.ncbi.nlm.nih.gov
26. 26Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man Neuroendocrinology, Oct 1997. pubmed.ncbi.nlm.nih.gov
27. 27Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study Nephrology Dialysis Transplantation, 1 Mar 2018. pubmed.ncbi.nlm.nih.gov
28. 28The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease (NCT05364684) ClinicalTrials.gov, 6 Jan 2026. clinicaltrials.gov
29. 29Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimulates the GH/insulin-like growth factor-I axis in selected GH-deficient adults The Journal of Clinical Endocrinology & Metabolism, Oct 1997. pubmed.ncbi.nlm.nih.gov
30. 30Phase 2 Study of LUM-201 in Children With Growth Hormone Deficiency (OraGrowtH210 Trial) (NCT04614337) ClinicalTrials.gov, 17 Jun 2026. clinicaltrials.gov
31. 31Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
32. 32Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act U.S. Food and Drug Administration, 14 May 2026. fda.gov
33. 33World Anti-Doping Code International Standard: Prohibited List 2027 World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
34. 34Warning letter to Dynamic Health Group dba SARMS America (MARCS-CMS 719257) U.S. Food and Drug Administration, 12 Dec 2025. fda.gov
35. 3521 CFR Part 1308, Schedules of Controlled Substances (eCFR, as of 25 September 2026) Electronic Code of Federal Regulations (eCFR), 25 Sep 2026. ecfr.gov
36. 36Final Summary Minutes of the Pharmacy Compounding Advisory Committee Meeting, October 29, 2024 U.S. Food and Drug Administration, 15 Jan 2025. fda.gov
37. 37X post by HHS Secretary Robert F. Kennedy Jr. (@SecKennedy) on peptides removed from Category 2 X (formerly Twitter), 15 Apr 2026. x.com
38. 38July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee U.S. Food and Drug Administration, 6 Aug 2026. fda.gov
39. 39Unauthorized workout supplements may pose serious health risks (RA-73367) Health Canada, 9 Jul 2025. recalls-rappels.canada.ca
40. 40Weightlifting Athlete Accepts Sanction for Anti-Doping Rule Violations U.S. Anti-Doping Agency, 20 Feb 2026. usada.org
41. 41Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue Clinica Chimica Acta, 1 Jan 2026. pubmed.ncbi.nlm.nih.gov
42. 42MK-677 (Ibutamoren) Dosage, Safety & Stacks Peptide Initiative, 25 Aug 2026. peptideinitiative.com
43. 43Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet JAMA, 28 Nov 2017. pubmed.ncbi.nlm.nih.gov
44. 44Reversible Gynecomastia and Hypogonadism Due to Usage of Commercial Performance-Enhancing Supplement Use JCEM Case Reports, Aug 2024. pubmed.ncbi.nlm.nih.gov
45. 45SwissChems homepage (‘Most Popular’ list) SwissChems (vendor), accessed 30 Sep 2026. swisschems.is (seller page, deliberately not linked)
46. 46Hepatotoxicity induced by MK-677 BMJ Case Reports, 17 Jul 2025. pubmed.ncbi.nlm.nih.gov
47. 47FDA Adverse Event Reporting System (FAERS) reports naming ibutamoren or MK-677, retrieved via the openFDA drug/event API U.S. Food and Drug Administration (openFDA), 30 Jul 2026. api.fda.gov · data query
48. 48LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report Experimental Physiology, Dec 2022. pubmed.ncbi.nlm.nih.gov
49. 49Spontaneous Splenic Rupture in a Patient With Recent Use of Performance-Enhancing Compounds: A Case Report and Literature Review Cureus, Mar 2026. pubmed.ncbi.nlm.nih.gov
50. 50Meeting of the Pharmacy Compounding Advisory Committee (to be held before the end of February 2027) U.S. Food and Drug Administration, 15 Apr 2026. fda.gov
51. 51PubMed search: (ibutamoren OR “MK-677” OR “MK-0677” OR MK677 OR “LUM-201”) AND (“resistance training” OR “resistance exercise” OR “strength training” OR weightlifting OR “weight lifting” OR bodybuilding OR bodybuilders OR athletes) (13 results; none a trial in people who lift weights) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
52. 52ClinicalTrials.gov search: ibutamoren OR MK-677 OR MK-0677 OR MK0677 OR LUM-201 (14 studies; none in young, healthy people who lift weights, none of an injected form and none of sleep) ClinicalTrials.gov, accessed 8 Oct 2026. clinicaltrials.gov
53. 53PubMed search: (ibutamoren OR “MK-677” OR “MK-0677” OR MK677 OR “LUM-201”) AND sleep (5 results; the only sleep study is the 1997 one cited here) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
54. 54PubMed search: (ibutamoren OR “MK-677” OR “MK-0677” OR MK677 OR “LUM-201”) AND (intravenous OR intravenously OR injection OR injections OR injected OR subcutaneous OR subcutaneously) (22 results; none a human trial of injected MK-677) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov