MK-677 (Ibutamoren)_Dosage, benefits & legal status
Also known as ibutamoren, MK-0677, Nutrobal, MK-677
A once-daily pill that raises growth hormone for sleep, appetite, and muscle.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is MK-677 (Ibutamoren)?
Plain language first. The technical label stays, but it never stands alone.Overview
It keeps your own growth hormone and IGF-1 raised around the clock for sleep, appetite, muscle, and skin, without needles.
MK-677 (ibutamoren) is a ghrelin-receptor agonist and, unlike the injectable peptides here, a small molecule that works as a daily pill.
What it's used for
A once-daily pill that raises growth hormone for better sleep, appetite, muscle, and skin, with no needles.
How does MK-677 (Ibutamoren) work?
What it does in the body, and where.MK-677 reaches the ghrelin receptor as an oral small molecule rather than an injected peptide, and it does not stop.
- 01It activates the ghrelin receptor as a daily pillNo injection, and no cold chain.
- 02Growth hormone and IGF-1 stay raised around the clockUnlike the injectable peptides, which produce pulses, this holds levels up continuously.
- 03That continuous elevation is the trade-offNatural growth hormone release is pulsatile. Constant elevation brings water retention, raised blood sugar, and increased appetite, and the long-term consequences are not well characterised.
- 04Appetite increases substantiallyOften the first thing people notice, and the reason many stop.
A schematic of the compound's mechanism, not a diagnostic image.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
Muscle and hormones
Investigational- Human trialIn 65 adults aged 60 to 81 over two years, lean mass rose 1.1 kg while the placebo group lost 0.5 kg.
- Human trialGrowth hormone rose 1.8-fold and IGF-1 rose 1.5-fold, back toward young-adult levels.
- Human trialA single dose raised 24-hour growth hormone output by about 97% in older adults.
- Human trialDespite the hormone changes, there was no significant improvement in strength or physical function.
Sleep and side effects
Investigational- Human trialIn younger people, high doses increased deep sleep duration by roughly 50%.
- Human trialFasting blood sugar rose measurably, reflecting mildly worse insulin sensitivity.
- Human trialIt also raised bone-turnover markers and modestly increased cortisol.
The published record
136
Records indexed for MK-677 (Ibutamoren)
81 in humans, 50 of them original studies.
8 registered trials, 2 with posted results.
FDA: Category 2 · FDA: Category 2 · FDA: In category 2 (503A and 503B).
Counted from Europe PMC indexing, not read by a person. Human means indexed under humans, which includes reviews and work on human cells. Original studies exclude reviews and lab work on human cells.Last updated 12 September 2026.
At a glance
Four things to know about MK-677 (Ibutamoren)
Evidence
Research only
Category
Growth hormone
Common vial
Varies
Half-life
About 24 hours
How much, and do you cycle it?
The range, and whether you take breaks.10 up to 25 mg per day, daily, at night. Not cycled in the research. Commonly cycled by users anywayHuman study
The longest controlled trial gave MK-677 daily for two years and the effect did not wear off, so the tolerance argument for cycling does not hold here. Insulin sensitivity did decline across those two years. Fasting blood sugar rose early on, though by the two-year mark that rise was no longer statistically significant. If there is a reason to take breaks from this one, it is metabolic rather than receptor tolerance.
How long does it stay in the body?
The half-life, and where the figure comes from.About 24 hoursHuman study
Not yet traced to a primary source.
You can compare this against the whole library to see where it sits.
What does it cost?
Typical dose and cost, in plain numbers.MK-677 (Ibutamoren) is not injected
It is taken by mouth (oral).
MK-677 (Ibutamoren) starts at $66.99 across 8 vendors.
10 listings, last read Sep 5, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Room temperature. Cool, dry, out of light.
MK-677 (Ibutamoren) is taken as a pill or capsule. Keep it in its original container at room temperature, away from heat, humidity, and direct sun. No fridge or mixing needed. Check the expiration date on the bottle.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- Heart failure or significant heart disease, after a fracture trial was stopped early over heart-failure concerns
- Diabetes or poorly controlled blood sugar
- Active cancer
- Pregnancy
- Banned in drug-tested sport
Stop and get help
- Shortness of breath, or swelling in the legs and ankles, which can signal heart strain
- Signs of high blood sugar such as constant thirst or blurred vision
- New lumps or masses
- Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing
Common effects
- Increased appetite, often strongly
- Water retention and puffiness
- Tiredness or grogginess
- Joint aches
- Rising blood sugar over time
What regulators say
- FDA: Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (interim categories 1, 2, 3), updated May 14, 2026Category 2
Listed as Ibutamoren Mesylate; safety risk cited is potential congestive heart failure
Checked 11 September 2026 - FDA: Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (category 2 and withdrawn nominations), current as of April 22, 2026In category 2 (503A and 503B)
503A September 29, 2023; 503B December 29, 2022. Trial terminated early over a congestive heart failure signal
Checked 11 September 2026 - FDA: Bulk Drug Substances Nominated for Use in Compounding Under Section 503B (interim categories 1, 2, 3), updated March 21, 2025Category 2
Listed as Ibutamoren Mesylate; added December 29, 2022
Checked 11 September 2026
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is MK-677 (Ibutamoren) approved?
And where the numbers on this page come from.No. MK-677 (Ibutamoren) is not approved for any use, anywhere. It is sold labelled for laboratory research only, and there is no legal route to buy it for human use.
- Approval statusResearch only
- RouteBy mouth (oral)
- CheckedJuly 2026
What has happened recently
Never approved anywhere. A trial in hip-fracture patients was stopped early over heart-failure concerns, and it is banned in drug-tested sport.
Banned in drug-tested sport. Most research peptides are prohibited under WADA's S0 category, which covers any substance with no approval from any regulatory authority for human use. That means a compound can be banned without ever being named on the prohibited list. Check with your own anti-doping authority rather than assuming absence from the list means permitted.
You can compare this against the whole library, or read how to check a seller.
- DoseFrom research and community reports. No regulator has reviewed this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
- Reviewed22 July 2026
What else is like MK-677 (Ibutamoren)?
Others in Growth hormone peptides, side by side.If you're weighing MK-677 (Ibutamoren), it's worth reading HGH (Somatropin), Tesamorelin + Ipamorelin blend, and Sermorelin + Ipamorelin blend in the same class.
A once-daily pill that raises growth hormone for sleep, appetite, and muscle.
- Dose
- 10 up to 25 mg per day
- How often
- Daily, at night
Real injected growth hormone, the most powerful and priciest option.
- Dose
- 1 up to 3 IU per day (start low, increase slowly)
- How often
- Daily
Two growth-hormone signals in one shot, built around the belly-fat peptide.
- Dose
- 1.28 up to 2 mg tesamorelin per day (the ipamorelin follows your ratio)
- How often
- Daily, often at night
The entry-level clinic combo, with one legal half and one that is not.
- Dose
- 0.2 up to 0.5 mg sermorelin per dose (the ipamorelin follows your ratio)
- How often
- Nightly
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
- US Department of Defense, Operation Supplement Safety on MK-677(2024)US Department of Defense review; notes it is unapproved and banned in sport.
- Nass two-year trial, Annals of Internal Medicine, 2008
- Nass two-year trial, PubMed, 2008
- FDA, bulk drug substances for compounding that may present significant safety risks(2026)Ibutamoren mesylate is one of the few peptide-adjacent compounds still on the live category 2 list, under both 503A (29 September 2023) and 503B (29 December 2022). The stated reason is not a paperwork concern: FDA points to a randomized, placebo-controlled trial in patients recovering from hip fracture that was terminated early over a potential safety signal of congestive heart failure.
Last reviewed 22 July 2026
Beyond these, 136 records are indexed. Browse the records