MK-677 (ibutamoren)
This experimental oral drug raises growth hormone and IGF-1; risks include high blood sugar and swelling.
Also called: Ibutamoren, Ibutamoren mesylate, Ibutamoren mesilate, MK-0677, MK0677, LUM-201, L-163,191.
Growth hormone secretagogues (ghrelin receptor) · Non-peptide ghrelin-receptor agonist and growth hormone secretagogue.
What MK-677 (ibutamoren) does
MK-677 is an oral small molecule, not a peptide. Trials found higher growth hormone and IGF-1, but better strength or recovery did not reliably follow. It can raise blood sugar, increase hunger and cause swelling. A hip-fracture trial stopped early over heart-failure concerns. Pediatric growth trials remain separate from adult self-use.
- In a trial of older adults, it raised lean body mass, though strength and function did not improve. (Studied in a trial)
- Studies show it raises growth hormone and IGF-1 in the blood; better strength or recovery did not reliably follow. (Studied in a trial)
- Small, short studies found changes in deep and REM sleep; long-term sleep benefit is unknown. (Studied in a trial)
- People report better sleep and an easier time eating more. (Reported by users)
Uses in the sources
- Studied for lean mass in older adults and men with obesity. More lean mass did not reliably improve strength or function. (Studied in a trial) (source)
- Two hip-fracture trials did not establish better overall recovery. One stopped early over heart-failure concerns. (Studied in a trial) (source)
- Small studies found changes in deep and REM sleep. Long-term benefit for insomnia is unknown. (Studied in a trial) (source)
- Investigational for selected children with GH deficiency. A phase 3 trial is recruiting; there is no approved pediatric dose. (Studied in a trial) (source)
- A 563-person Alzheimer trial raised IGF-1 without slowing clinical decline. (Studied in a trial) (source)
- People report using it for bulking, hunger and sleep. Forum reports cannot separate drug effects from training, diet or other drugs. (Reported by users) (source)
MK-677 (ibutamoren) dosage
Typical reported dose: 25 mg by mouth each morning
- Older adults: 25 mg each morning: 25 mg orally once each morning. once daily, by mouth. Studied in a trial. Studied in: Healthy adults aged 60-81; 71 randomized and 65 completed year 1. (source)
- Obese men: 25 mg daily: 25 mg orally once daily; no titration. once daily, by mouth. Studied in a trial. Studied in: Otherwise healthy men aged 18-50 with obesity. (source)
- Hip-fracture study: 25 mg: 25 mg orally once daily; no titration. once daily, by mouth. Studied in a trial. Studied in: Previously mobile adults aged at least 65 after hip-fracture surgery. (source)
- Stopped hip-fracture trial: 25 mg: 25 mg orally once daily; no titration. once daily, by mouth. Studied in a trial. Studied in: Older adults recovering from hip fracture. (source)
- Alzheimer trial: 25 mg daily: 25 mg orally once daily; no titration. once daily, by mouth. Studied in a trial. Studied in: Adults with mild to moderate Alzheimer disease. (source)
- Dialysis crossover: 25 mg: 25 mg orally once daily; no titration. once daily, by mouth. Studied in a trial. Studied in: Adults on hemodialysis; 22 completed the crossover. (source)
Highest studied: Repeated fixed adult dosing reached 50 mg/day briefly. A separate study used single 90 mg doses; pediatric trials reached 3.2 mg/kg/day..
These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.
How to store MK-677 (ibutamoren)
Comes as: Trial oral tablets, Trial oral capsules, Trial flavored oral solution.
Mixed with: No approved home diluent or injectable formulation. An older trial used a prepared 2 mg/mL flavored oral solution..
- OraGrowtH210 tablets came in 9, 18 and 36 mg strengths; they were not to be divided, chewed or crushed.
- Oral liquids, tablets and research powders are not sterile injectable medicines.
- No human injection regimen or peptide-style vial reconstitution schedule was established.
Before mixing: OraGrowtH210 trial tablets: 15-25°C (59-77°F). This does not establish storage or shelf life for unrelated online products.
After mixing: No validated shelf life or home-mixing storage schedule was found for consumer oral liquids.
MK-677 (ibutamoren) side effects and risks
Reported side effects
- Increased hunger: 29/43, 67%, versus 8/22, 36%, placebo in the older adult trial., mild. Track appetite and weight; persistent unwanted hunger needs review. (source)
- Leg swelling or water retention: 19/43, 44%, versus 6/22, 27%, placebo., moderate. New swelling needs review. Breathlessness or rapid weight gain needs urgent care. (source)
- Muscle pain: 14/43, 33%, versus 2/22, 9%, placebo., mild. Review persistent pain; pain plus marked swelling needs prompt assessment. (source)
- Joint pain: 25/43, 58%, versus 17/22, 77%, placebo. It was not more frequent on MK 677., moderate. Two treated women reduced dose for joint pain and later withdrew. (source)
- Higher blood sugar or HbA1c: Fatty liver pilot: 4/12, 33.3%; no concurrent control. Alzheimer trial: glucose rise 15.4% versus 4.6% placebo., moderate. Check glucose and HbA1c; thirst and frequent urination need prompt review. (source)
- Heart failure: Hip fracture trial: 4/62, 6.5%, versus 1/61, 1.7%, placebo; trial stopped early., serious. Stop and seek urgent care for breathlessness, chest pain or rapidly worsening swelling. (source)
- Higher blood pressure: Hip fracture trial: mean systolic rise 11.9 16.4 mmHg versus 2.3 to +2.3 placebo across visits., moderate. Monitor blood pressure and fluid gain; persistent elevation needs review. (source)
- Liver injury or raised liver enzymes: One 2025 case after 2 months; reversible enzyme rises also occurred in trials. General incidence is unknown., serious. Stop and get prompt care for yellow skin, dark urine or persistent upper-belly pain. (source)
- Tiredness or sleepiness: Reported in Alzheimer trial drug related events and community use; reliable individual event rates unavailable., moderate. Review new daytime sleepiness; avoid driving while sleepy. (source)
- Numbness or carpal-tunnel symptoms: Reported in trial safety summaries; reliable overall rate unknown., moderate. Persistent tingling, weakness or hand pain needs review. (source)
Stop and get help if
- Breathlessness, chest pain, fainting or swelling with rapid weight gain: Stop use and get urgent medical care now.
- Severe thirst, frequent urination, vomiting, deep breathing or confusion: Check glucose if available and get urgent care. Severe symptoms need emergency assessment.
- Yellow skin or eyes, dark urine or persistent upper-belly pain: Stop use and seek prompt medical assessment for possible liver injury.
- Severe headache with vision change or vomiting: Get urgent assessment. Raised pressure around the brain is a GH-class concern.
- Face or throat swelling, trouble breathing or collapse: Call emergency services now.
- Sudden severe left-sided belly pain with dizziness or fainting: Get emergency care. A mixed-use case reported spleen rupture; causation remains unproven.
- Low glucose with confusion, seizure or fainting while using diabetes medicines: Get emergency help. Starting or stopping a glucose-altering drug can change medicine needs.
Who should avoid it
- under18: Pediatric studies require specialist trial care. They do not establish safe self-use in minors.
- pregnant: No established pregnancy safety; pregnancy was excluded from the adult liver trial.
- breastfeeding: Milk transfer and infant safety are unknown; breastfeeding was excluded from the adult liver trial.
- tryingToConceive: Reproductive safety is unknown. Trial contraception rules are a research safeguard, not proof of safety.
- activeCancer: It raises GH and IGF-1. Avoid with active cancer; this screen extrapolates from GH treatment guidance.
- cancerHistory: Review past cancer with the treating team. MK-677 trials cannot establish recurrence safety.
- heartCondition: Fluid retention may worsen heart disease. A hip-fracture trial stopped over heart-failure concerns.
- other: The heart-failure signal and fluid retention make further exposure unsafe without assessment.
- diabetes: Blood sugar can rise and insulin sensitivity can fall, even when fasting glucose initially looks normal.
- diabeticRetinopathy: Active severe eye disease needs specialist review. This is a GH-class precaution, not a measured MK-677 risk.
- uncontrolledBloodPressure: Blood pressure rose in the hip-fracture trial; fluid retention adds concern.
- kidneyDisease: A small dialysis study is not proof of kidney safety. Fluid balance and drug handling need review.
- liverDisease: Liver injury has been reported. Safe dose changes for liver disease are not established.
- surgeryPlanned: Tell the surgical team about use. Glucose and fluid shifts matter around surgery.
- testedAthlete: WADA prohibits ibutamoren at all times under S2.2.4 in the 2026 list.
- pancreatitisHistory: Pancreatitis is a GH-treatment warning; FDA flags possible class risks for MK-677. Direct ibutamoren risk is unmeasured.
- other: Insulin sensitivity can worsen before fasting glucose changes. Mixed-use diabetes cases included people with prior metabolic risk.
Interactions
- Insulin: Reduced insulin sensitivity may change insulin needs. This is a GH-class concern; direct MK-677 interaction trials are lacking.
- Sulfonylureas: Glucose control may worsen. Changing or stopping MK-677 may change medicine needs; do not adjust doses from forum advice.
- Other GH secretagogues, growth hormone or IGF-1: Duplicate growth signals may add swelling and glucose effects. Combination efficacy and safe doses are not established.
- SARMs and anabolic steroids: Mixed-use reports show liver, lipid and hormone harms. Unknown product contents can add further drugs.
- Berberine and self-added glucose-lowering products: Forum use does not prove protection from insulin resistance. Added glucose-lowering products can complicate glucose management.
- Systemic corticosteroids: Both can worsen blood sugar. GH can also alter steroid replacement needs; this is class-based, not a proven MK-677 interaction.
- Anticoagulants: CYP or P-glycoprotein effects could change some anticoagulant levels. This is a lab-based concern; clinical interaction size is unknown.
- CYP3A inhibitors and grapefruit: May raise ibutamoren exposure. Trial protocols excluded moderate or strong CYP3A inhibitors and prohibited grapefruit; clinical effect sizes are unknown.
- CYP3A inducers: May lower exposure. Trial protocols excluded strong CYP3A inducers; no validated compensating dose change exists.
- Sensitive CYP substrates: Ibutamoren induced several CYP enzymes in lab tests. Trial protocols restricted sensitive substrates; actual clinical level changes are unknown.
Product quality risks
- TGA testing in June 2026 found an undeclared anabolic steroid in tested MK-677 capsules.
- A 44-product internet survey found 25% with unlisted drugs and 59% with amounts differing from labels. These were mixed performance products, not 44 MK-677 products.
- A separate 60-supplement study detected undeclared MK-677 in some products. It did not establish a market-wide contamination rate.
- A 2025 official-laboratory survey covered 324 samples; ibutamoren was among the five most frequent drugs. Some quantified products were overdosed.
- Identity, dose, impurities and contamination cannot be inferred from appearance or a research-use label.
- FDA records December 2025 warning letters concerning ibutamoren products in its supplement-ingredient directory.
What to expect
- Early months: In the older-adult trial, daily MK-677 commonly increased appetite, while mild leg swelling and muscle pain were also reported.
- Within a few months: The trial reported that increased appetite faded within a few months for many participants.
- Month 12: Lean mass increased without better strength or function, and fasting blood sugar rose while insulin sensitivity fell in the older-adult trial.
An older-adult trial used 25 mg by mouth daily for one year, with a second year of follow-up treatment.
34 original human research records include case reports and ongoing trials; some share participants. Phase 3 is in children, with no results yet.
Key studies
- Older adults: lean mass and glucose: Lean mass increased, but strength and function did not improve. (source)
- Hip fracture: stopped over heart failure: Most function measures did not improve; heart-failure concerns ended the trial. (source)
- Earlier hip-fracture trial: Higher IGF-1 did not establish better recovery. (source)
- Alzheimer disease: no benefit: Raising IGF-1 did not slow Alzheimer disease. (source)
- Obese men: lean mass and glucose tolerance: The trial did not show fat loss and detected impaired glucose tolerance. (source)
- Obese men: bone turnover: Secondary hormonal or bone findings do not establish health benefits. (source)
MK-677 (ibutamoren) FAQ
- Is MK-677 (ibutamoren) FDA-approved? No approved label. FDA's December 2025 warning letters, linked in its ingredient directory, state that ibutamoren is excluded from dietary supplements.
- How do people take it? By mouth, once daily. 12 months, then randomized continuation or switch. Source: studied in a trial.
- What's the difference between MK-677 (ibutamoren) and Retatrutide? MK-677 (ibutamoren): this experimental oral drug raises growth hormone and IGF-1; risks include high blood sugar and swelling. Retatrutide: an experimental weekly injection with phase 3 weight-loss results. Why people pair them: proposed to combine growth-hormone effects with appetite control and hoped-for metabolic protection.
- Can I take it with Retatrutide? Proposed to combine growth-hormone effects with appetite control and hoped-for metabolic protection. No human trial validates this pairing. Retatrutide cannot be assumed to prevent MK-677 glucose or fluid harms. Source: reported by users. Ask a doctor before combining anything.
- Is it banned in sport? Yes. It is banned in and out of competition (WADA 2026). Ibutamoren, MK-677, is explicitly named in the 2026 list, effective 1 January 2026.
- How do I store it once opened? No validated shelf life or home-mixing storage schedule was found for consumer oral liquids.
Related to MK-677 (ibutamoren)
- Ipamorelin: An experimental peptide that triggers growth hormone release.
- GHRP-2: A peptide that releases growth hormone and can increase hunger.
- GHRP-6: A peptide studied in growth hormone tests and an experimental stroke combination.
- Hexarelin: A peptide that releases growth hormone; repeated use can weaken the response.
- Retatrutide: An experimental weekly injection with phase 3 weight-loss results.
Sources
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act, FDA · FDA · 2026
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, FDA · FDA · 2026
- The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
- Unapproved ibutamoren capsules (MK-677) found to contain undisclosed anabolic steroid, Therapeutic Goods Administration · 2026
- 503A Categories Update for September 2024, FDA · FDA · 2025
- October 29, 2024 Meeting of the Pharmacy Compounding Advisory Committee, FDA · 2024
- October 29, 2024 Pharmacy Compounding Advisory Committee (PCAC) Meeting, FDA · 2024
- Anaphylaxis, NHS · NHS · 2023
- Scheduling delegate's final decisions, April 2018, Therapeutic Goods Administration · 2018
- Evaluation and treatment of adult growth hormone deficiency: an Endocrine Society clinical practice guideline., Molitch ME et al. · The Journal of clinical endocrinology and metabolism · 2011
- EU/3/17/1882 - orphan designation for treatment of growth hormone deficiency, European Medicines Agency
- Information on Select Dietary Supplement Ingredients and Other Substances, FDA
- Search Orphan Drug Designations and Approvals, FDA · FDA
- Supply unlicensed medicinal products (specials), MHRA · MHRA
- Unauthorized workout supplements may pose serious health risks, Health Canada
Sources checked: 2026-10-18.
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