MK-677 (Ibutamoren) Compounding Pharmacy FDA and State Board Enforcement History

What FDA Has Done About MK-677

MK-677 (ibutamoren mesylate) is not an FDA-approved drug. It is not a component of any FDA-approved product, has no USP or National Formulary monograph, and is an oral, non-peptide small molecule that stimulates growth hormone release through the ghrelin receptor — not a peptide, and not a SARM [7].

Category 2 on FDA's compounding lists

FDA lists ibutamoren mesylate among bulk drug substances that raise significant safety risks for compounding — its category 2 [1]. It was added December 29, 2022 for outsourcing facilities and September 29, 2023 for state-licensed pharmacies and physicians, and it remains on both lists, which were updated March 21, 2025 for outsourcing facilities and May 14, 2026 for state-licensed pharmacies and physicians [1][2][3]. Category 2 substances fall outside FDA's policy of generally not acting against compounders, and the agency says it would consider action under its general enforcement policies [5].

FDA's stated reason is that ibutamoren 'poses significant safety risks due to the potential for congestive heart failure in certain patients', and it points to a hip-fracture trial that was terminated early over that signal [1][11].

The October 2024 advisory committee vote

On October 29, 2024 FDA's Pharmacy Compounding Advisory Committee voted 1 yes, 13 no, 0 abstain against adding ibutamoren mesylate to the list of bulk substances that can be used in compounding, in line with FDA's own proposal; members cited fluid retention, congestive heart failure and hyperglycemia [4][7]. FDA's review found that one outsourcing facility had reported compounding a 25 mg capsule in 2019 and 2020 and none since [4].

A warning letter and a hidden-ingredient notice

On December 12, 2025 FDA sent a warning letter to Musclepower Enterprise Ltd., doing business as MONSTER KING and GE LABS, over products marketed as SARMs that included 'GE Labs MK 677'. FDA stated that ibutamoren 'is excluded from the dietary supplement definition' because it had been authorized for investigation as a new drug, substantial clinical investigations were instituted, and it was not marketed as a supplement or food before that, and that products marketed with drug claims are 'unapproved new drugs' [12].

On September 23, 2025 FDA warned that Agebox iKids Growth Day Formula, promoted to stimulate growth in children aged 5 and older, contained ibutamoren that was not listed on the label. FDA listed risks including increased appetite, water retention, fatigue, muscle pain, changes in glucose metabolism and insulin sensitivity, and said it 'may increase the potential for congestive heart failure in certain individuals' [13].

Can a Compounding Pharmacy Make MK-677?

FDA states that state-licensed pharmacists and physicians may compound from a bulk substance only if it complies with a USP or NF monograph when one exists, is a component of an FDA-approved drug when no monograph exists, or appears on FDA's list of bulk substances that can be used in compounding; the substance must also come with a valid certificate of analysis and be made by an establishment registered with FDA [5]. Ibutamoren has no monograph and is not a component of any approved drug [7], and FDA's advisory committee voted against adding it to that list [4].

Compounded drugs are not FDA-approved in any setting; FDA does not verify their safety, effectiveness or quality before they are marketed [6].

Does the Federal Peptide Policy Cover It?

No. The HHS draft enforcement-discretion policy for compounded peptides, filed October 28, 2026 as Federal Register document 2026-22192 with publication scheduled for October 30, 2026, names six peptides: BPC-157, epitalon, KPV, MOTS-c, Semax and TB-500 [8][9]. Ibutamoren is not among them, and it is not a peptide at all [7].

What About State Pharmacy Boards?

According to FDA, state boards of pharmacy generally have primary responsibility for day-to-day oversight of state-licensed pharmacies that are not registered with FDA as outsourcing facilities, while outsourcing facilities are primarily overseen by FDA and inspected on a risk-based schedule [6]. FDA's category 2 listing covers state-licensed pharmacies and physicians as well as outsourcing facilities [1][3].

Why FDA Treats It as a Safety Risk

The trial behind the category 2 listing: Adunsky and colleagues randomized 123 patients aged 60 and older to MK-677 25 mg daily (n=62) or placebo (n=61) for 24 weeks, and the trial was stopped early for a safety signal of congestive heart failure — per FDA's summary, 4 patients (6.5%) on MK-677 versus 1 (1.7%) on placebo. Serious adverse events occurred in 24% versus 13%, systolic blood pressure rose 11.9 to 16.4 mmHg versus 2.3 to -2.3 on placebo, and blood glucose and HbA1c rose more on the drug. The authors concluded MK-677 'has an unfavorable safety profile' in this population [11][7].

In 65 healthy adults aged 60 to 81 given 25 mg daily for 12 months, fasting glucose rose about 5 mg/dL (P=0.015) and insulin sensitivity fell; body weight rose 2.7 kg versus 0.8 kg on placebo and fat-free mass rose 1.1 kg versus a 0.5 kg fall, but strength and function did not improve. The most frequent side effects were increased appetite, transient mild leg edema and muscle pain [14][7].

In 563 patients with mild to moderate Alzheimer's disease treated for 12 months, IGF-1 rose 72.9% with no effect on disease progression; drug-related adverse events were 35.5% versus 23.9%, blood glucose increases 15.4% versus 4.6%, and HbA1c increases 11.1% versus 1.4% [15].

FDA's wider concern is class-wide: by raising growth hormone and IGF-1 the drug may carry the risks listed on approved growth hormone labels, and FDA found no long-term safety data in the older adults it is marketed to [7].

Where MK-677 Sits Now

FDA has stated that ibutamoren is excluded from the dietary supplement definition and that products marketed for it with drug claims are unapproved new drugs [12], and FDA has confirmed it as an undeclared ingredient in a children's product [13]. In sport, WADA names ibutamoren (MK-677) in section S2.2.4 among growth hormone secretagogues and their mimetics, prohibited at all times in and out of competition, on the 2026 List and still on the 2027 List [10][16].

There is no approved dose. Trials used fixed oral doses of 2 mg to 50 mg per day, most often 25 mg once daily in adults, for up to 2 years; these are trial doses, not recommended doses [7].