MK-677 (ibutamoren): research

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.

34 original human research records include case reports and ongoing trials; some share participants. Phase 3 is in children, with no results yet.

Studies

Older adults: lean mass and glucose. rct, n=71, Healthy adults aged 60-81; 71 randomized and 65 completed year 1.. Lean mass increased, but strength and function did not improve. (source)
Hip fracture: stopped over heart failure. rct, n=123, Older adults recovering from hip fracture.. Most function measures did not improve; heart-failure concerns ended the trial. (source)
Earlier hip-fracture trial. rct, n=161, Previously mobile adults aged at least 65 after hip-fracture surgery.. Higher IGF-1 did not establish better recovery. (source)
Alzheimer disease: no benefit. rct, n=563, Adults with mild to moderate Alzheimer disease.. Raising IGF-1 did not slow Alzheimer disease. (source)
Obese men: lean mass and glucose tolerance. rct, n=24, Otherwise healthy men aged 18-50 with obesity.. The trial did not show fat loss and detected impaired glucose tolerance. (source)
Obese men: bone turnover. rct, n=24, Secondary analysis of the Svensson obese-men cohort.. Secondary hormonal or bone findings do not establish health benefits. (source)
Obese men: leptin and thyroid signals. rct, n=24, Secondary analysis of the Svensson obese-men cohort.. Secondary hormonal or bone findings do not establish health benefits. (source)
Obese men: blood lipids. rct, n=24, Secondary analysis of the Svensson obese-men cohort.. Secondary hormonal or bone findings do not establish health benefits. (source)
Obese men: GH forms. rct, n=12, Secondary analysis of the Svensson obese-men cohort.. Secondary hormonal or bone findings do not establish health benefits. (source)
Older adults: dose finding. rct, n=32, Healthy women and men aged 64-81.. GH and IGF-1 rose, alongside fasting glucose. (source)
Young men: 5 and 25 mg. crossover-rct, n=9, Healthy young men.. One-week dosing altered GH pulses and raised IGF-1. (source)
GH-deficient men: 10 and 50 mg. crossover-rct, n=9, Men aged 17-34 with severe childhood-onset GH deficiency.. 50 mg daily was tested briefly; it is not an established long-term dose. (source)
Sleep: young and older adults. crossover-rct, n=14, Eight adults aged 18-30 and six adults aged 65-71.. Sleep-stage changes came from very small, short experiments. (source)
Calorie restriction: nitrogen balance. crossover-rct, n=8, Healthy volunteers aged 24-39 on 18 kcal/kg/day.. One week reduced nitrogen loss during calorie restriction. (source)
Bone turnover: three older-adult trials. rct, n=187, Healthy older adults and older adults with function limits, aged at least 65.. Bone breakdown and formation markers rose; fracture prevention was not tested. (source)
Osteoporosis: MK-677 with alendronate. rct, n=292, Postmenopausal women aged 64-85 with low femoral-neck bone density.. An added benefit at one bone site did not establish fewer fractures. (source)
Children: short GH-response study. rct, n=18, Prepubertal children with idiopathic GH deficiency.. Some children showed hormone responses; growth was not measured. (source)
Children: six-month growth and response markers. rct, n=68, Treatment-naive prepubertal children with GH deficiency; 68 evaluable completers.. Growth responses depended on remaining GH function. (source)
Children: single-dose GH response. cohort, n=68, Same pediatric trial cohort analyzed by Bright 2021.. The GH response identified a subset with retained hormone reserve. (source)
Dialysis: IGF-1 crossover study. crossover-rct, n=26, Adults on hemodialysis; 22 completed the crossover.. IGF-1 rose; nutrition, strength and survival benefits remain untested. (source)
Fibromyalgia: completed, results unavailable. rct, n=64, Adults with fibromyalgia.. Completed trial has no posted results or located peer-reviewed outcome paper. (source)
Advanced kidney disease: withdrawn. rct, Planned adults with stage 4/5 chronic kidney disease.. Zero participants enrolled; this record supplies no human efficacy or safety evidence. (source)
Fatty liver: registry results. open-label, n=12, Adults with BMI at least 25 and fatty liver; 7 with six-month outcome data.. Small study did not show a significant liver-fat benefit. (source)
OraGrowtH210: dose finding. rct, n=104, Children with selected GH deficiency; 104 qualification doses, 82 randomized.. Posted growth results were lower than the concurrent rhGH arm. (source)
OraGrowtH212: hormone pulses and PK. rct, n=24, Children with idiopathic GH deficiency; registry target 24, published conference analyses include 22.. Registry has no results table; published conference analyses are listed separately. (source)
OraGrowtH213: one-year extension. open-label, n=15, Children completing a prior LUM-201 trial.. The posted growth score cannot be interpreted as actual growth without clarification. (source)
OraGrowtH211: long-term safety. open-label, n=60, Children completing an earlier LUM-201 trial; planned enrollment 60.. Enrolling by invitation; no results posted. (source)
OraGrowtH: phase 3 recruiting. rct, n=150, Treatment-naive prepubertal children with GH deficiency; planned n=150.. Recruiting phase 3 trial; no results posted as of 2026-10-18. (source)
Phase 3 safety extension: planned. open-label, n=150, Children from phase 3; estimated enrollment 150.. Not yet recruiting; no exposed participants or results established. (source)
Older adults: semaglutide combination planned. rct, n=202, Older adults with obesity; estimated enrollment 202.. Combination is registered but not yet recruiting; no combination results exist. (source)
LGD-4033 plus MK-677: one user. case-report, n=1, A recreationally active 25-year-old man.. Combination use coincided with weight gain and worse liver, lipid and hormone markers. (source)
Liver injury after reported MK-677. case-report, n=1, Otherwise healthy man in his early 30s.. A liver-injury report adds a safety signal, without establishing incidence. (source)
Breast growth and low testosterone: mixed products. case-report, n=1, 40-year-old man using several performance products.. Mixed, uncertain products prevent attribution to MK-677 alone. (source)
Spleen rupture after mixed performance drugs. case-report, n=1, 54-year-old man reporting MK-677 and RAD-140 use.. A serious event followed mixed use; the suggested drug link remains speculative. (source)
Hair detection after low-dose exposure. pk-study, n=2, One single-dose volunteer and one performance-enhancement user.. Hair tests can detect exposure; these values do not establish a safe dose. (source)
Single 5 mg dose: plasma assay. pk-study, Human plasma after an oral dose; participant number not stated.. An early assay paper documents a 5 mg human oral exposure. (source)
Severe high glucose after a mixed cycle. case-report, n=1, 47-year-old recreational bodybuilder with prior high fasting glucose, obesity and fatty liver.. Severe hyperglycemia followed mixed use in a man with pre-existing metabolic risk. (source)
Diabetes after a combination tablet. case-report, n=1, 34-year-old man with BMI 38.2 and a strong family history of type 2 diabetes.. Diabetes was diagnosed after mixed use; the report cannot identify one causal drug. (source)
Liver injury after mixed performance drugs. case-report, n=1, 24-year-old man described in a 2019 conference case, as summarized by FDA.. FDA identified a mixed-use liver-injury report; MK-677 causation was not established. (source)
Clinic records: body composition. cohort, n=145, 145 hypogonadal men using testosterone; MK-677 subgroup size not reported in the abstract.. A conference abstract found body-composition changes in clinic records; it cannot isolate treatment effects. (source)
Clinic abstract: fluid retention. cohort, n=161, Hypogonadal men: 106 on testosterone alone; 55 on testosterone plus a GH secretagogue.. Ibutamoren was associated with greater water retention in clinic records. (source)
2026 sports-medicine evidence review. systematic-review, Published animal and human studies of six compounds, including MK-677.. A structured review found weak human benefit evidence and cardiovascular and glucose risks. (source)
2026 urology evidence review. review, Literature on peptide-related therapies in urology and sexual medicine.. The review distinguishes hormone changes from established clinical benefits. (source)
Original oral secretagogue discovery. animal, Rat pituitary cells and dogs.. Established a non-peptide oral GH secretagogue before human trials. (source)
How ibutamoren binds the ghrelin receptor. in-vitro, Receptor structural and laboratory experiments.. Receptor binding explains hormone effects; it does not establish clinical benefit. (source)
Capsule versus tablet: single-dose PK. crossover-rct, Human formulation study; sample size, ages and participant health status were not stated in the abstract.. The abstract supports formulation-specific exposure data but contains a food-effect inconsistency. (source)
Two pediatric trials: pooled interim results. cohort, n=30, Overlapping OraGrowtH210 and OraGrowtH212 cohorts; 15 children per dose at 6 months.. Doubling the dose did not improve growth in this small pooled interim analysis. (source)
OraGrowtH212: published growth and GH data. cohort, n=22, 22 selected prepubertal children with moderate GH deficiency in Chile.. A conference report provides outcomes despite absent results on the study registry. (source)
Pediatric GH patterns and growth. cohort, n=22, Same 22 OraGrowtH212 children.. Timing of GH bursts may matter beyond the total hormone amount. (source)
Pediatric GH timing: exploratory analysis. cohort, n=22, Same 22 children in the OraGrowtH212 hormone-profile dataset.. A mathematical analysis linked hormone timing patterns to growth-response groups. (source)
Older-adult GH timing and insulin sensitivity. cohort, n=43, 43 healthy adults aged 60-81: 27 women and 16 men.. Lower insulin sensitivity was associated with larger changes in GH timing patterns. (source)
Semaglutide combination: mouse experiment. animal, n=40, Male mice with diet-induced obesity; 10 per group.. Mouse results motivated a planned human trial; they do not establish a human stack. (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.

Work out syringe units with the dosing calculator

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.

How MK-677 (ibutamoren) works

It activates the ghrelin receptor, which helps control hunger and growth hormone release. This raises growth hormone and IGF-1. Higher hormone levels do not prove better health.

GHSR-1a, the ghrelin receptor: Signals the brain and pituitary to increase growth hormone release; can increase hunger.
GH and IGF-1 pathway: Changes growth signals, fluid balance and how the body handles blood sugar.

Half-life: A reliable numeric human elimination half-life was not confirmed in the retrieved primary reports.

Gaps: No established adult benefit for lifespan, cancer prevention, injury healing or reliable strength gains. No large long-term safety study in healthy young bodybuilding users; cancer, heart and diabetes risks remain uncertain. No validated protection from cycling, weekend breaks, microdosing, berberine or P5P. No reliable human elimination half-life or absolute oral bioavailability confirmed in the retrieved primary reports. No pregnancy, breastfeeding or fertility safety basis for self-use. Pediatric growth-response studies do not establish final adult height benefit or safety in healthy children. The 2026 phase 3 trial has no results yet. Planned semaglutide pairing is not completed combination evidence. Exact interaction studies, kidney or liver dose adjustments and stability of self-made solutions are missing. Community prevalence is qualitative; post authors, products, doses and outcomes were not independently verified. Registry and paper enrollment counts conflict for Alzheimer, hip-fracture and dialysis trials; the profile preserves each discrepancy. Short older-adult trials and secondary papers have possible cohort overlap. A precise count of all unique human participants is unavailable. No compound-specific UK possession or personal-import determination was established. Monitoring intervals are practical harm-reduction extrapolations, not a validated MK-677 clinical-practice schedule. The original Flores 2019 case abstract was not recovered; its inclusion relies on FDA's published summary. The OraGrowtH213 registry growth endpoint is internally unclear and needs sponsor clarification. No FDA or EMA dose label. One 2018 clinician review proposed 25 mg daily; it is not a society guideline or established healthy-user regimen. Clinic abstracts omit the MK-677 dose and subgroup size; possible overlap prevents a unique-cohort count. No human injection or sublingual dose study was found. Sparse comments cannot establish either regimen. Repeated fixed adult doses reached 50 mg/day briefly; a formulation study used single 90 mg doses. A universal absolute human maximum is unknown. The 2025 capsule abstract has contradictory food-effect numbers and does not report sample size or the salt/base dose basis. Pediatric conference reports repeatedly analyze the same trials and differ by data cut; they are not independent replications. GLP-1-related forum pairings are proposals, not proof that one experimental drug offsets another drug's harms.

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.

MK-677 (ibutamoren): the short version

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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