MK-677 (Ibutamoren) vs Tesamorelin
Updated November 4, 2026 · Reviewed by the PeptidesDB Editorial team
A data-driven comparison of MK-677 (Ibutamoren) and Tesamorelin (also searched as Tesamorelin vs MK-677 (Ibutamoren)) — effect profiles, evidence, side effects, and which suits weight loss, muscle, or healing goals.
Verdict
MK-677 (Ibutamoren) centers on muscle, while Tesamorelin leans toward metabolic. On indexed research, MK-677 (Ibutamoren) is ahead (MK-677 (Ibutamoren): 25 studies, Human evidence; Tesamorelin: 13, Human clinical). Choose by goal — and read the primary studies. This is research information, not medical advice.
Key takeaways
- •MK-677 (Ibutamoren) is strongest for muscle; Tesamorelin for metabolic.
- •Evidence: MK-677 (Ibutamoren) Human evidence (25 studies) vs Tesamorelin Human clinical (13).
- •Check the FDA-approval status chips above before assuming a legal use pathway.
Effect profiles, overlaid
At a glance
Ghrelin receptor agonist | Muscle mass enhancement
GHRH analog | Reduces visceral fat in HIV lipodystrophy
MK-677 (Ibutamoren) vs Tesamorelin: side-by-side
| Metric | MK-677 (Ibutamoren) | Tesamorelin |
|---|---|---|
| Class | Muscle | Metabolic |
| Regulatory status | Research use only | FDA-approved |
| Evidence grade | Human evidence | Human clinical |
| Studies indexed | 25 | 13 |
| Research level | Limited Research | FDA Approved |
| Strongest effect | Muscle & body comp | Metabolic & appetite |
| Healing & recovery | 1.0▲ | 1.0▲ |
| Muscle & body comp | 4.0▲ | 2.0 |
| Metabolic & appetite | 3.0 | 5.0▲ |
| Neuro & mood | 2.0▲ | 2.0▲ |
| Sleep & circadian | 3.0▲ | 1.0 |
| Inflammation & immune | 1.0▲ | 1.0▲ |
| Skin & aesthetics | 3.0▲ | 3.0▲ |
▲ marks the higher AI-assigned effect score (0–5, describing where the literature concentrates — not clinical efficacy).
Mechanism & pharmacokinetics
| Property | MK-677 (Ibutamoren) | Tesamorelin |
|---|---|---|
| Mechanism | Oral ghrelin-receptor agonist (GH secretagogue) | GHRH analog |
| Route | Oral | Subcutaneous injection |
| Half-life | ~4–6 h | ~26–38 min |
| 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 MK-677 (Ibutamoren)?
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 →What is Tesamorelin?
Tesamorelin is a synthetic peptide that acts as a growth hormone-releasing hormone (GHRH) analog. It is primarily investigated for its potential to reduce visceral fat in individuals with HIV-associated lipodystrophy, a condition characterized by abnormal fat distribution often exacerbated by antiretroviral therapy. Tesamorelin stimulates the release of endogenous growth hormone, which in turn promotes lipolysis and reduces visceral adipose tissue (VAT) accumulation.
Full Tesamorelin profile, mechanism & studies →Which is better for your goal?
| Goal | Better fit | Why |
|---|---|---|
| Healing | Even | Both ~1.0/5 |
| Muscle | MK-677 (Ibutamoren) | 4.0/5 effect signal |
| Metabolic | Tesamorelin | 5.0/5 effect signal |
| Neuro | Even | Both ~2.0/5 |
| Sleep | MK-677 (Ibutamoren) | 3.0/5 effect signal |
| Inflammation | Even | Both ~1.0/5 |
| Skin | Even | Both ~3.0/5 |
Fit reflects community-perceived effect profiles — not head-to-head trials. Read each peptide's studies before deciding.
Can you stack MK-677 (Ibutamoren) and Tesamorelin?
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 at least one is a research-use compound, we don't publish stacking or dosing protocols here. Any combination should be discussed with a qualified clinician.
MK-677 (Ibutamoren) vs Tesamorelin: 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
MK-677 (Ibutamoren) has 25 approved studies indexed (Human evidence), and Tesamorelin has 13 (Human clinical). 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 MK-677 (Ibutamoren) or Tesamorelin better?
It depends on your goal. MK-677 (Ibutamoren) is strongest for muscle; Tesamorelin for metabolic. MK-677 (Ibutamoren) has more indexed studies (25). See the goal-by-goal breakdown above.
Is MK-677 (Ibutamoren) or Tesamorelin better for weight loss?
Tesamorelin shows the stronger metabolic & appetite profile (5.0/5) in the AI-assigned effect profile — though weight-loss outcomes depend on the individual and the evidence base.
Is MK-677 (Ibutamoren) or Tesamorelin better for muscle?
MK-677 (Ibutamoren) leads on the muscle & body-composition axis (4.0/5).
Which has more research, MK-677 (Ibutamoren) or Tesamorelin?
MK-677 (Ibutamoren) has 25 approved studies indexed (Human evidence); Tesamorelin has 13 (Human clinical). Higher counts mean more to read, not proven superiority.
Can you stack MK-677 (Ibutamoren) and Tesamorelin?
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 MK-677 (Ibutamoren) vs Tesamorelin?
MK-677 (Ibutamoren): no community-reported effects logged yet. Tesamorelin: none logged yet. These are anonymous reports, not incidence rates — see each profile.
Is MK-677 (Ibutamoren) or Tesamorelin FDA-approved?
MK-677 (Ibutamoren) is a research-use compound and is not FDA-approved. Tesamorelin is FDA-approved. Research-use status is not a legal clearance to compound or use in humans.
Is Tesamorelin better than MK-677 (Ibutamoren)?
For metabolic, Tesamorelin has the edge; for muscle, MK-677 (Ibutamoren) 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
Approval status varies (see the chips at the top). 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 November 4, 2026.