Hexarelin vs MK-677 (Ibutamoren)
Updated July 21, 2026 · Reviewed by the PeptidesDB Editorial team
A data-driven comparison of Hexarelin and MK-677 (Ibutamoren) (also searched as MK-677 (Ibutamoren) vs Hexarelin) — effect profiles, evidence, side effects, and which suits weight loss, muscle, or healing goals.
Verdict
Hexarelin centers on muscle, while MK-677 (Ibutamoren) leans toward muscle. On indexed research, Hexarelin is ahead (Hexarelin: 4 studies, Human evidence; MK-677 (Ibutamoren): 4, Human evidence). Choose by goal — and read the primary studies. This is research information, not medical advice.
Key takeaways
- •Hexarelin is strongest for muscle; MK-677 (Ibutamoren) for muscle.
- •Evidence: Hexarelin Human evidence (4 studies) vs MK-677 (Ibutamoren) Human evidence (4).
- •Both are research-use compounds — not FDA-approved.
Effect profiles, overlaid
At a glance
Examorelin | Synthetic Growth Hormone Secretagogue
Hexarelin vs MK-677 (Ibutamoren): side-by-side
| Metric | Hexarelin | MK-677 (Ibutamoren) |
|---|---|---|
| Class | GH | — |
| Regulatory status | Research use only | Research use only |
| Evidence grade | Human evidence | Human evidence |
| Studies indexed | 4 | 4 |
| Research level | Well Studied | — |
| Strongest effect | Muscle & body comp | Muscle & body comp |
| Healing & recovery | 1.0▲ | 0.0 |
| Muscle & body comp | 4.0▲ | 4.0▲ |
| Metabolic & appetite | 3.0▲ | 3.0▲ |
| Neuro & mood | 2.0▲ | 0.0 |
| Sleep & circadian | 1.0 | 2.0▲ |
| Inflammation & immune | 2.0▲ | 0.0 |
| Skin & aesthetics | 3.0▲ | 0.0 |
▲ marks the higher community effect score (0–5 perceived-effect signal, not clinical efficacy).
Mechanism & pharmacokinetics
| Property | Hexarelin | MK-677 (Ibutamoren) |
|---|---|---|
| Mechanism | — | Oral ghrelin-receptor agonist (GH secretagogue) |
| Route | — | Oral |
| Half-life | — | ~4–6 h |
| Duration of action | — | Daily dosing |
Established pharmacology — curated for well-characterized compounds and AI-summarized otherwise. A blank (—) means no reliable single value is published (half-life figures for some peptides genuinely disagree across sources). Verify against primary sources such as FDA labels and ClinicalTrials.gov.
What is Hexarelin?
### Hexarelin Summary Hexarelin is a synthetic hexapeptide that belongs to the growth hormone secretagogue (GHS) class, known for its ability to stimulate growth hormone release from the pituitary gland. It has been investigated for its potential therapeutic applications in various conditions, including muscle wasting and age-related decline in growth hormone levels.
Full Hexarelin profile, mechanism & studies →What is MK-677 (Ibutamoren)?
### Summary MK-677, also known as Ibutamoren, is a growth hormone secretagogue that has garnered attention for its potential effects on muscle mass and body composition. Research is ongoing to better understand its mechanisms and applications in various contexts, including its detection in biological samples.
Full MK-677 (Ibutamoren) profile, mechanism & studies →Which is better for your goal?
| Goal | Better fit | Why |
|---|---|---|
| Healing | Hexarelin | 1.0/5 effect signal |
| Muscle | Even | Both ~4.0/5 |
| Metabolic | Even | Both ~3.0/5 |
| Neuro | Hexarelin | 2.0/5 effect signal |
| Sleep | MK-677 (Ibutamoren) | 2.0/5 effect signal |
| Inflammation | Hexarelin | 2.0/5 effect signal |
| Skin | Hexarelin | 3.0/5 effect signal |
Fit reflects community-perceived effect profiles — not head-to-head trials. Read each peptide's studies before deciding.
Can you stack Hexarelin and MK-677 (Ibutamoren)?
People sometimes combine peptides that target different pathways, but there is little controlled research on this specific pairing and the interactions aren't well characterized. Because neither compound is FDA-approved, we don't publish stacking or dosing protocols here. Any combination should be discussed with a qualified clinician.
Hexarelin vs MK-677 (Ibutamoren): side effects
No community-reported effects logged yet.
No community-reported effects logged yet.
Anonymous community reports (count = number of reports), not clinical incidence rates.
What the research says
Hexarelin has 4 approved studies indexed (Human evidence), and MK-677 (Ibutamoren) has 4 (Human evidence). The Librarian re-checks PubMed, Europe PMC and ClinicalTrials daily, so these counts move. Open each profile to read the summaries and sources.
Frequently asked questions
Is Hexarelin or MK-677 (Ibutamoren) better?
It depends on your goal. Hexarelin is strongest for muscle; MK-677 (Ibutamoren) for muscle. Hexarelin has more indexed studies (4). See the goal-by-goal breakdown above.
Is Hexarelin or MK-677 (Ibutamoren) better for weight loss?
They score similarly on the metabolic/appetite axis in the community data.
Is Hexarelin or MK-677 (Ibutamoren) better for muscle?
Both land close on the muscle & body-composition axis.
Which has more research, Hexarelin or MK-677 (Ibutamoren)?
Hexarelin has 4 approved studies indexed (Human evidence); MK-677 (Ibutamoren) has 4 (Human evidence). Higher counts mean more to read, not proven superiority.
Can you stack Hexarelin and MK-677 (Ibutamoren)?
Some users combine peptides, but there's little controlled data on this specific pairing, and interactions aren't well characterized. We don't publish stacking protocols for compounds that aren't FDA-approved. Discuss any combination with a qualified clinician.
What are the side effects of Hexarelin vs MK-677 (Ibutamoren)?
Hexarelin: no community-reported effects logged yet. MK-677 (Ibutamoren): none logged yet. These are anonymous reports, not incidence rates — see each profile.
Is Hexarelin or MK-677 (Ibutamoren) FDA-approved?
Hexarelin is a research-use compound and is not FDA-approved. MK-677 (Ibutamoren) is not FDA-approved. Research-use status is not a legal clearance to compound or use in humans.
Is MK-677 (Ibutamoren) better than Hexarelin?
For muscle, MK-677 (Ibutamoren) has the edge; for muscle, Hexarelin does. Neither is universally "better" — it's goal-dependent, and both should be weighed against their evidence base above.
Comparing related peptides
Regulatory & legal status
Hexarelin and MK-677 (Ibutamoren) are research-use compounds and are not FDA-approved for human use. FDA approval and compounding rules for peptides change frequently, and research-use status is not a legal clearance for human use. The FDA does not review compounded drugs for safety, effectiveness, or quality. Verify current status with primary sources before acting. Last reviewed July 21, 2026.