Whether MK-677 is legal depends on what you’re doing with it. Ibutamoren, sold under the name MK-677, is not a controlled substance in the United States, so possessing or using it is not a crime you can be arrested for. Selling it for human consumption, however, violates federal drug law, and using it will get you sanctioned in almost any organized sport, in NCAA athletics, and in the U.S. military.
Not Scheduled, But Not Approved Either
MK-677 does not appear on any schedule of the Controlled Substances Act.1Drug Enforcement Administration. Drug Scheduling That is the source of most confusion. People hear “not controlled” and assume the compound is freely legal to buy, sell, and use. It isn’t.
The FDA treats MK-677 as an unapproved new drug. No manufacturer has taken it through the drug approval process, so it has no recognized medical use in the United States. The agency has also concluded that ibutamoren is excluded from the legal definition of a dietary supplement, which means it cannot be lawfully sold in a capsule with a Supplement Facts label.2U.S. Food and Drug Administration. Warning Letter – Dynamic Health Group dba SARMS AMERICA Selling it for human use violates the Federal Food, Drug, and Cosmetic Act.3U.S. Food and Drug Administration. Agebox Inc. – 718252
Congress has considered adding SARMs to Schedule III through the SARMs Control Act, but the bill has not become law. Even if it did, MK-677 might fall outside its scope, because ibutamoren is a growth hormone secretagogue rather than a SARM.
What Sellers Actually Risk
Selling an unapproved new drug in interstate commerce violates 21 U.S.C. § 331. A first offense carries up to one year in prison and a fine of up to $1,000. A repeat offense, or one committed with intent to defraud, carries up to three years and a fine of up to $10,000.4Office of the Law Revision Counsel. 21 USC 333 – Penalties Knowingly importing unapproved drugs for commercial distribution can bring up to ten years and fines up to $250,000.
The FDA usually opens with a warning letter and refers cases for criminal prosecution when companies ignore them. In December 2025, the agency sent warning letters to multiple sellers, including one marketing MK-677 as a children’s growth supplement and another selling it openly by name.2U.S. Food and Drug Administration. Warning Letter – Dynamic Health Group dba SARMS AMERICA
The “Research Chemical” Label Doesn’t Insulate Sellers
Most vendors sell MK-677 with disclaimers like “for research purposes only” or “not for human consumption.” The FDA looks past the label to actual intent. If the marketing, packaging, dosage instructions, or website content describes effects in humans, the FDA treats it as an unapproved drug being sold illegally. The SARMS America warning letter turned in part on the company’s own website describing MK-677’s effects on muscle mass, body fat, bone density, and sleep quality in people.2U.S. Food and Drug Administration. Warning Letter – Dynamic Health Group dba SARMS AMERICA
Ordering From Overseas
Importing MK-677 from a foreign supplier is generally illegal, even when the product is legal where it shipped from. The FDA’s rule is that importing unapproved drugs for personal use is not permitted, and Customs and Border Protection can seize shipments at the border.5FDA.gov. Personal Importation6U.S. Customs and Border Protection. Can I have medications mailed to me from outside the United States?
A narrow personal importation policy allows some unapproved drugs into the country when they treat a serious condition with no domestic alternative, are limited to roughly a three-month supply, pose no unreasonable health risk, and come with a U.S. doctor’s name or evidence that treatment began abroad.5FDA.gov. Personal Importation MK-677 used for bodybuilding or anti-aging does not qualify. Some small shipments slip through, but that reflects enforcement priorities, not legality.
Australia, one of the more common source countries, classifies ibutamoren as a Schedule 4 prescription-only medicine, and importing it requires a permit granted only to prescribing doctors or pharmacists.7Sport Integrity Australia. Ibutamoren (MK 677) Information8Therapeutic Goods Administration. Consumer Story: Tim and Selective Androgen Receptor Modulators (SARMs)
People Who Face More Than a Legal Question
For most private users, MK-677 will not trigger a criminal case against them personally. Certain populations face a different calculus, because their governing bodies impose their own consequences.
Athletes Under WADA Rules
The World Anti-Doping Agency lists ibutamoren by name on its 2026 Prohibited List under section S2.2.4, covering growth hormone secretagogues.9World Anti-Doping Agency. International Standard Prohibited List 2026 The ban applies at all times, in and out of competition, with no off-season window.7Sport Integrity Australia. Ibutamoren (MK 677) Information Athletes have been sanctioned, and those who cannot prove contamination typically face bans of two to four years.
College Athletes
The NCAA lists ibutamoren (MK-677) by name as a banned substance under peptide hormones, growth factors, related substances, and mimetics.10NCAA. 2025-26 NCAA Banned Substances Any chemically or pharmacologically related substance is also banned, even if not individually named. A positive test costs eligibility, and the NCAA reported an increase in positive ibutamoren tests during the 2024-25 season. Athletes are held strictly liable for what enters their body, regardless of what a supplement label disclosed.
Military Personnel
MK-677 appears on the Department of Defense Prohibited Dietary Supplement Ingredients List. Service members are prohibited from using any product containing ibutamoren.11Operation Supplement Safety. Performance Enhancing Substance: MK-677 (Ibutamoren) Beyond the civilian legal question, using a prohibited supplement can trigger UCMJ action and jeopardize a security clearance.