Growth Hormone
MK-677
Ibutamoren
A tablet, not an injection, which is really the whole selling point for people chasing growth hormone and muscle without a needle. Long-term safety hasn't been nailed down, and it's known to ramp up appetite and affect blood sugar.
Oral growth-hormone with substantial human pharmacology data. In older adults it increased fat-free mass without improving strength or function; safety concerns limit any simple wellness interpretation.
How well studied
Tier Guide: A = Well studied, B = Some good studies, C = Early evidence & D = Barely studied
Tested in people, but in smaller or fewer studies. A decent picture, just less certain.
UK status
How you could legitimately come across it here, if at all
No authorised UK medicine contains this, and we have no record of a routine UK clinic route. Material sold online is unregulated.
Evidence strength and UK regulatory status answer different questions.
Overview
How it works
Works by mimicking ghrelin, the 'hunger hormone', which is exactly why it tends to leave people hungrier.
An oral that raises GH and levels, taken as a tablet rather than injected.
Reported benefits
- Raises GH and IGF-1 in human studies
- In a two-year older-adult trial, increased fat-free mass but did not improve strength or physical function
- Not established as a performance, recovery or anti-ageing treatment
Who it's typically used for
Timeline to results
Safety & UK access
Dosage
No established self-administration dose for general wellness use.
Side effects
- Increased appetitevery common in controlled oral trials
- Fluid retention and swellingcommon in controlled trials in older adults
- Higher fasting glucose and reduced insulin sensitivityreported in controlled trials
- Congestive heart failuresafety signal: excess cases contributed to the early termination of the hip-fracture trial
Getting it in the UK
No authorised UK medicine contains this, and we have no record of a routine UK clinic route. Material sold online is unregulated.
Where it turns up
- Not routinely available in the UK
- Unregulated online market
No authorised UK medicinal product containing ibutamoren/MK-677 was identified. Online availability is not evidence of UK authorisation or product quality.
Not MHRA-licensed and not typically part of the UK private-clinic prescribing route
MHRA: the UK regulator that assesses whether a medicine is safe and works before it can be authorised for use here. Something not being MHRA-licensed does not automatically mean it is illegal, and it does not mean it is safe.
This is background information about UK regulation, not advice about what you can or should obtain.
Evidence & sources
Why this rating?
The A to D rating shown above comes from our earlier editorial review and is still waiting to be migrated into the structured review record below. That is a gap in our record-keeping, not a sign the rating is wrong.
Evidence fingerprint
No route and indication scope has been published for this profile yet, so no fingerprint is shown.
Sources
Structured source audit not yet published for this profile. The references behind this page are being catalogued one compound at a time, and this one has not been through that process yet.
Content freshness
- Last reviewed
- 24 Sept 2026
- Regulatory status last checked
- 21 Aug 2026