Educational Wellness Information Only
This platform provides peer-reviewed research summaries and educational content about peptides for wellness and optimization purposes. Nothing on this site is intended as medical advice, diagnosis, or treatment. We do not claim any peptide can diagnose, treat, cure, or prevent any disease. Always consult a licensed healthcare provider before beginning any wellness protocol.
Statements on this site have not been evaluated by the FDA. Compounded preparations are subject to applicable state and federal regulations. Availability and eligibility vary.
MK-677 (Ibutamoren) vs Tesamorelin
An educational, source-based comparison of MK-677 (Ibutamoren) and Tesamorelin — how each peptide works, what it's researched for, and what to know before going deeper.
Orally bioavailable non-peptide ghrelin mimetic.
Technically a small-molecule ghrelin receptor agonist (not a peptide), often grouped with peptide GH research. Orally bioavailable, it elevates GH and IGF-1 over 24 hours and increases appetite.
- GH/IGF-1 elevation in adults
- Lean mass and bone density in elderly
- Sleep quality (slow-wave sleep)
- • Not FDA-approved.
- • Insulin resistance and fluid retention reported.
- • Banned by WADA.
A stabilized analog of growth hormone-releasing hormone (GHRH) that stimulates pulsatile endogenous GH and IGF-1 release. FDA-approved (Egrifta) for the reduction of excess abdominal visceral fat in HIV-infected patients with lipodystrophy.
- Visceral adipose tissue reduction (approved)
- Cognitive function in older adults (research)
- NAFLD / hepatic fat (research)
- • FDA-approved only for HIV-associated lipodystrophy.
- • May affect glucose tolerance; monitor in at-risk patients.
- • Requires physician oversight.
Trial-evidence rating
Educational grade reflecting how many peer-reviewed studies and FDA actions we cite for each peptide. Not a clinical recommendation.
Early-stage research; conclusions are tentative.
FDA-approved with published clinical trial data.
Study-by-study comparison
| Peptide | Study | Source | Year | Summary |
|---|---|---|---|---|
| MK-677 (Ibutamoren) | MK-677 increases GH and IGF-1 in elderly adults | Annals of Internal Medicine | 2008 | Two-year RCT showing sustained IGF-1 elevation and lean mass increase. |
| Tesamorelin | Tesamorelin for HIV-associated lipodystrophy | New England Journal of Medicine | 2007 | Phase 3 trials showing significant visceral fat reduction. |
| Tesamorelin | Tesamorelin and NAFLD in HIV | The Lancet HIV | 2019 | Reduced hepatic fat fraction in HIV-infected adults with NAFLD. |
Side-effect & safety grid
- Not FDA-approved.
- Insulin resistance and fluid retention reported.
- Banned by WADA.
- FDA-approved only for HIV-associated lipodystrophy.
- May affect glucose tolerance; monitor in at-risk patients.
- Requires physician oversight.
Educational summary of considerations reported in research literature — not a complete list of adverse events. Discuss with a licensed clinician before any use.
MK-677 (Ibutamoren) vs Tesamorelin — Key differences
- Class: MK-677 (Ibutamoren) is classified as Growth Hormone Axis · Small Molecule, while Tesamorelin is Growth Hormone Axis.
- Primary research focus: MK-677 (Ibutamoren) — gh/igf-1 elevation in adults; Tesamorelin — visceral adipose tissue reduction (approved).
- Tag: Growth hormone · Oral vs Body composition.