MK-677 can increase growth hormone and IGF-1. This does not demonstrate that it makes you stronger, speeds up your recovery or improves your health. Human trials show effects on certain markers and body composition, with metabolic risks and a cardiac safety signal in a vulnerable population.
My view is against self-medication. No ibutamoren-based medicine was identified in the French registers checked for this article, and the substance is prohibited at all times under the 2026 anti-doping list. To understand this judgment, clinical results must be read separately from sales promises.
MK-677 and ibutamoren: neither a SARM, a peptide nor GH
MK-677, MK-0677 and ibutamoren refer to the same substance in publications. It is a non-peptide GH secretagogue : a synthetic compound that stimulates growth hormone release by activating the ghrelin receptor, GHSR-1a. It is not directly administered GH.
Nor is it a SARM, meaning a selective androgen receptor modulator. A store may group them together, but commercial categorization does not define their pharmacology. The article on ipamorelin and CJC-1295 covers different substances, which are peptides.
Ghrelin receptor activation also plays a role in appetite. GH stimulates IGF-1 production, among other effects, but it also affects metabolism. This cascade explains why a genuine hormonal effect can come with adverse effects rather than a functional gain. The article on GH and longevity · FR helps explain why a “younger” value is not automatically a health target.
The regulatory review in the FDA document on ibutamoren describes these mechanisms and experimental indications. This is a US document: it does not determine approval in France.
Human trials: in whom, and to measure what?
There are genuine human trials, unlike some research products with almost exclusively preclinical evidence. The problem is applying their findings to a healthy athlete who wants to recover between training sessions.
The full text of the 2008 Nass trial was reviewed, along with the relevant sections of the 2024 FDA document. For the other trials in the table, results are reported from indexed primary abstracts. This review does not allow verification of all their methodological details or individual adverse events. The Nass trial was funded by the NIH and conducted at the University of Virginia, with tablets supplied by Merck.
| Trial and population | Comparator and duration | What was actually measured | Result and relevant limitation |
|---|---|---|---|
| Svensson, 1998: 24 men with obesity, aged 18 to 50 | MK-677 versus placebo, 8 weeks, 12 per group | GH, IGF-1, fat-free mass, fat, energy expenditure and glucose tolerance | Fat-free mass increased, total and visceral fat were not significantly reduced, glucose tolerance worsened |
| Nass, 2008: adults aged 60 to 81, 71 randomized, 65 completed the first year | MK-677 versus placebo, main analysis at 12 months, exploratory second year with treatment changes | Body composition, strength, function, quality of life and metabolism | Lean mass increased, without significant improvement in strength or function, insulin sensitivity decreased |
| Bach, 2004: 161 people aged 65 or older after hip fracture | MK-0677 versus placebo, 6 months of treatment followed by 6 months of follow-up | Functional performance, independence and IGF-1 | IGF-1 increased, functional differences were not significant |
| Adunsky, 2011: 123 older patients after hip fracture | MK-0677 versus placebo, assessment at 24 weeks, trial stopped early | Several functional measures and IGF-1 | Some favorable results, no improvement in most measures, heart failure signal |
| Sevigny, 2008: 563 patients with mild to moderate Alzheimer’s disease | MK-677 versus placebo, 12 months | Cognition, global clinical impression, daily activities and severity | IGF-1 increased, without significant slowing of progression on the outcomes studied |
Table sources: Svensson, Nass, Bach, Adunsky, Sevigny.
A patient undergoing rehabilitation after a fracture, an older adult and someone who lifts weights do not have the same goal. The data reviewed do not validate a course of treatment in healthy athletes. Experimental amounts are therefore not reproduced here as a dosing protocol.
Lean mass, water and strength: three different outcomes
Fat-free mass encompasses the entire body apart from fat. Lean mass measured by DXA includes water and soft tissues. These measurements describe body composition, but they do not directly quantify contractile proteins added to a muscle.
In the Nass trial, at 12 months, fat-free mass measured by DXA increases by an average of 1.1 kg with MK-677, compared with a decrease of 0.5 kg with placebo. The difference between the mean changes is therefore 1.6 kg, not an individual promise of 1.6 kg of muscle.
Total body water also increases. But reducing the entire result to edema would be inaccurate: the authors measure fluid compartments, and changes in intracellular water contribute to their interpretation of an effect on cell mass. Yet the study does not demonstrate a significant improvement in strength or functional tests.
Two opposite errors must therefore be avoided. “It is all water” oversimplifies the result. “It is all useful muscle” attributes an unproven benefit to it. The decisive question remains function: weight moved, walking ability, independence or performance measured in an appropriate trial.
The study was small and primarily powered to assess body composition. The absence of a significant difference does not prove that any effect is impossible, but it does not justify claiming a gain in strength.
Recovery, sleep and cognition: scrutinizing the promises
A Biaxol commercial document published in 2025 associates ibutamoren with muscle growth, recovery, fat loss and sleep. It is used here to identify claims to verify, not to validate a product.
For recovery, the Bach trial shows no significant difference in functional measures after fracture. The Adunsky trial reports a favorable result on a walking speed score, but not on several other measures. Even that result concerns medical rehabilitation, not the time needed before another training session.
For sleep, there is a small 1997 study. Eight young adults take part in seven-day periods with placebo and crossover treatments. Six older adults undergo fourteen-day periods under a different design. Changes in sleep stages are reported, but these sample sizes and durations demonstrate neither treatment of insomnia nor lasting athletic recovery. REM sleep is not synonymous with deep slow-wave sleep, contrary to the wording of the commercial document.
For cognition, the Alzheimer’s trial provides a particularly clear counterexample: an increase in IGF-1 did not slow clinical progression. This does not rule out every conceivable cognitive effect in every population. It does, however, rule out presenting the GH–IGF-1 mechanism as proof of a nootropic benefit.
Blood glucose and appetite: measured risks
The eight-week trial in men with obesity reports an impaired response to an oral glucose tolerance test, while fasting glucose and insulin concentrations do not change significantly. Unchanged fasting blood glucose therefore does not capture the entire metabolic response.
The FDA, in its 2025 ibutamoren-specific alert, lists increased appetite, water retention, fatigue, muscle pain and possible changes in carbohydrate metabolism or insulin sensitivity. It also notes a potential risk of heart failure in some people.
Increased appetite may be presented as an advantage for bulking. It remains a pharmacological effect that can change food intake. Weight gain does not prove the quality of the tissues gained, and a feeling of recovery tells you nothing about changes in blood glucose.
Someone with diabetes, prediabetes, heart disease, edema or hypertension should not interpret results from a selected group as a personal guarantee. Trials often exclude certain diseases and do not describe every profile exposed through online sales. Interactions and the effects of combinations with other substances remain insufficiently established to recommend self-medication.
The cardiac signal: serious, but population-dependent
The Adunsky trial was stopped early after a congestive heart failure signal. In this older population after hip fracture, the FDA document reports 4 cases among 62 participants receiving MK-0677, versus 1 among 61 receiving placebo.
These small numbers do not allow a precise estimate of the risk in a young athlete. Nor do they prove that every user will develop heart failure. They require this signal to remain part of the benefit–risk assessment, rather than focusing only on the increase in IGF-1.
The commercial document reviewed describes generally mild effects and cites a percentage of users with no negative effects. Such a figure, without a clinical protocol allowing verification of recruitment, follow-up and denominators, does not carry the same weight as a controlled trial.
The available data also cannot rule out rare effects or consequences of several years of use in healthy people. Stimulation described as “natural” because it uses your own pituitary gland remains a pharmacological intervention.
Online products and testimonials: two additional uncertainties
Product risk adds to the risk of the substance itself. In June 2026, the Australian TGA detected an undeclared anabolic steroid in one brand’s capsules sold as MK-677. This alert concerns an identified product; it does not prove that all products on offer contain a steroid. It shows why a label alone does not establish actual exposure.
An HPLC analysis does not demonstrate clinical efficacy. Identity, content, impurities and sample representativeness must also be distinguished. The guide to certificates and contamination of research products · FR explains these analytical questions, even though MK-677 is not a peptide.
A positive review may reflect training, calories, expectations of an effect or other products. A negative testimonial does not always allow a symptom to be attributed to ibutamoren rather than an undeclared substance. Testimonials can flag a problem, but they do not measure a causal benefit or a reliable frequency of adverse effects.
France: approval and anti-doping status, checked October 10, 2026
No ibutamoren-based medicine was identified in the French files listing medicinal products and their compositions, or in the European register of centralized authorizations checked. No trade name authorized in France was found. MK-677 is explicitly prohibited at all times under the 2026 WADA List, in category S2.2.4.
The regulatory check used the terms ibutamoren, MK-677 and MK-0677. The files from the French Public Medicines Database are dated September 29, 2026. The European register consulted covers only the centralized procedure: the absence of a result in that register alone is not enough to assess all national authorizations.
A commercial offer, shipping to France or a “research use only” label does not constitute marketing authorization. Trial registration or a development designation does not constitute approval either. This check does not claim to resolve every legal case involving importation or possession.
For sport, the 2026 WADA List is explicit: ibutamoren is listed among GH secretagogues and their mimetics, prohibited in and out of competition. The S2 classification also includes non-peptide mimetics. The category heading therefore does not make MK-677 a peptide.
The ban does not mean that every performance claim has been demonstrated. It describes a sporting rule. Stopping a few days before a competition does not authorize use, and no elimination period is provided here to evade a test.
Consultation checklist, without a dosing protocol
If you have already used a product sold as MK-677, the cautious approach is to stop self-medicating and speak to a doctor or pharmacist. Keep the packaging, batch number, exposure dates and list of other substances. Do not try to correct an effect with another product.
Prepare the following points for the consultation:
- Actual goal : fatigue, sleep, pain or difficulty recovering, with examples and duration.
- Metabolic risk : history of diabetes, known test results and current treatments.
- Cardiovascular risk : hypertension, heart disease, swelling or shortness of breath.
- Actual exposure : stated name, batch number, source and other hormones, SARMs or supplements.
- Status : no identified approval and anti-doping obligations if you participate in a sport covered by these rules.
Seek medical advice promptly for new swelling, unusual shortness of breath, thirst or very frequent urination. Severe breathing difficulty, chest pain or feeling unwell with loss of consciousness warrants calling 15 or 112 in France. These symptoms have several possible causes and do not allow a remote diagnosis.
My verdict: the hormonal mechanism is real, a recovery benefit in healthy athletes is not established, and the risks are not hypothetical. The next useful step is to understand the cause of your symptoms, not to turn trial doses into a personal course of treatment.
