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MK-677 (ibutamoren) regulatory status

Current status of MK-677 (ibutamoren) in the United States: Not eligible for compounding. In sport: WADA prohibited. Details, sources, and the dated timeline follow.

By the PeptideAgent Editorial Team. Draft, pending editorial review.  Last verified

What is the current status of MK-677 (ibutamoren)?

Regulatory: Not eligible for compoundingWADA: WADA prohibitedVerified: Verified Sep 23, 2026
FDA and compounding
Not FDA approved for any use. FDA placed ibutamoren mesylate in 503B Category 2 on December 29, 2022 and in 503A Category 2 on September 29, 2023, citing the potential for congestive heart failure based on the terminated hip fracture trial. As of the FDA page current to April 22, 2026, it remains in both categories, so no licensed pharmacy or outsourcing facility can lawfully compound it. It was not among the substances withdrawn from Category 2 in April 2026. It is widely sold online as a research chemical or mislabeled supplement.
WADA
WADA prohibited
Access path
  1. No lawful United States access path identified on the last verified date.
  2. Not available as an FDA approved product; FDA placed ibutamoren in both 503A and 503B Category 2, and it may not lawfully be sold as a dietary supplement.
  3. Products labeled research use only are not lawful for human use and are not verified for identity or purity.

Full MK-677 (ibutamoren) page: evidence, dosing in the literature, and sources

How has the status of MK-677 (ibutamoren) changed over time?

  1. WADA

    WADA publishes the 2027 Prohibited List

    WADA published the 2027 Prohibited List on September 21, 2026, and it takes effect January 1, 2027. The S2 peptide hormone and growth factor classes are unchanged. BPC-157 is still named under S0, and MOTS-c is still named under S4.4 as an activator of AMP-activated protein kinase. WADA added a note that many peptides without approval for human use fall under S0 or another section, and that a peptide not named on the list may still be prohibited. GLP-1 receptor agonists such as semaglutide and tirzepatide are still not on the list.

    Source: WADA 2027 Prohibited List
  2. WADA

    WADA 2026 Prohibited List takes effect

    The 2026 WADA Prohibited List took effect on January 1, 2026 and continues to prohibit the S2 peptide hormone and growth factor classes (GHRH analogs, growth hormone secretagogues, GH fragments, IGF-1 and analogs, MGF, thymosin beta-4 and derivatives, hCG and GnRH-class releasing factors in males), myostatin inhibitors, insulin and the AMPK activator MOTS-c under S4, desmopressin under S5, and BPC-157 under S0. GLP-1 receptor agonists such as semaglutide and tirzepatide are not on the list.

    Source: WADA Prohibited List
  3. WADA

    WADA 2025 Prohibited List keeps peptide hormones and growth factors banned at all times

    The 2025 WADA Prohibited List took effect on January 1, 2025. Section S2 (peptide hormones, growth factors, related substances and mimetics) covers GHRH analogs such as CJC-1295, sermorelin, and tesamorelin, growth hormone secretagogues such as ipamorelin, GHRP-2, GHRP-6, hexarelin, and ibutamoren (MK-677), growth hormone fragments such as AOD-9604, growth factors including IGF-1 and its analogs, MGF, and thymosin beta-4 (TB-500), and chorionic gonadotropin and releasing factors such as gonadorelin and kisspeptin (prohibited in males). Myostatin inhibitors such as ACE-031 fall under S4, insulin under S4 metabolic modulators, desmopressin under S5, and BPC-157 remains an S0 non-approved substance.

    Source: WADA Prohibited List
  4. FDA

    FDA places a batch of nominated peptides in 503A Category 2

    In September 2023 FDA updated its 503A bulk drug substances category lists to place a group of nominated peptides in Category 2, which means FDA identified significant safety risks and the substances may not be used in 503A compounding while the evaluation continues. Kisspeptin-10 and ibutamoren (MK-677) were added on September 29, 2023 and remain in Category 2 on the FDA page current as of April 22, 2026. BPC-157, CJC-1295, ipamorelin, AOD-9604, dihexa, DSIP, epitalon, KPV, MOTS-c, selank, semax, melanotan II, LL-37, thymosin alpha-1, and thymosin beta-4 fragment (TB-500) were also placed in Category 2 under the 503A interim policy; that same page now lists them as nominated but withdrawn (see the April 2026 event). Hexarelin, PNC-27, and 5-amino-1MQ have never appeared on the FDA category lists.

    Regulatory: Not eligible for compoundingSource: FDA: Certain bulk drug substances for use in compounding may present significant safety risks (503A and 503B Category 2 lists and withdrawn nominations, content current as of April 22, 2026)

Sources

Numbered citations in the answers above point here, followed by the regulatory sources on record for MK-677 (ibutamoren) and the source of each dated event.

  1. [1]FDA: Certain bulk drug substances for use in compounding may present significant safety risks (Category 2 list, content current as of April 22, 2026)FDA, 2026
  2. [2]FDA: Bulk drug substances used in compounding under section 503A of the FD&C ActFDA, 2026
  3. [3]WADA Prohibited List, section S2 peptide hormones, growth factors, related substances and mimetics (ibutamoren named)WADA, 2026
  4. [4]WADA 2027 Prohibited ListWADA, 2026