Peptides for Fat Loss
Research overview of peptides studied specifically for fat loss and body recomposition. GLP-1 agonists, AOD-9604, and lipolytic peptide research evidence.
Research Overview
Fat loss peptide research significantly overlaps with weight loss research but with specific focus on adipose tissue reduction and body composition rather than scale weight. GLP-1 receptor agonists dominate the clinical landscape, but growth hormone fragments and secretagogues are also studied for fat-specific effects.
AOD-9604, a growth hormone fragment, was specifically developed as a lipolytic agent without the diabetogenic effects of full GH. While initial research was promising, clinical development was discontinued and evidence remains limited. The compound is now available in unregulated markets.
Understanding the distinction between weight loss (total body mass) and fat loss (specifically adipose tissue) is important when evaluating peptide research. Many studies measure weight change without body composition analysis, making fat-specific claims difficult to validate.
Key Fat Loss Peptides
GLP-1 Agonists (Body Composition Data)
| Compound | Fat Mass Reduction | Lean Mass Effect |
|---|---|---|
| Semaglutide | ~65-70% fat | Some lean loss |
| Tirzepatide | ~70-75% fat | Better preservation |
| Retatrutide | Higher % fat | Under study |
While primarily weight loss drugs, body composition data shows majority fat loss.
AOD-9604
Status: Not approved (development discontinued)
| Aspect | Details |
|---|---|
| Origin | GH fragment (176-191) |
| Mechanism | Proposed lipolytic |
| Clinical evidence | Low (discontinued) |
| Current status | Gray market |
Initially promising but failed to demonstrate efficacy in Phase 2b trials.
Growth Hormone Secretagogues
| Peptide | Fat Loss Evidence |
|---|---|
| Tesamorelin | CT-measured visceral fat reduction in adults with HIV lipodystrophy; not general fat loss |
| MK-677 | No significant visceral or total fat reduction in the cited older-adult trial |
| GHRPs | Low |
Tesamorelin is approved for reducing excess abdominal fat in adults with HIV lipodystrophy, with trial evidence for CT-measured visceral adipose tissue reduction. EGRIFTA WR’s label says it is not indicated for weight management; these results do not establish general fat-loss use.
A randomized trial in 65 healthy older adults found no significant difference in visceral or total fat mass with MK-677 versus placebo. A fat-free-mass change is a separate endpoint and does not establish a fat-loss benefit.
Body Composition Considerations
| Peptide Class | Fat Loss | Muscle Preservation |
|---|---|---|
| GLP-1 agonists | Strong | Modest concern |
| Dual/triple agonists | Strong | May be better |
| GH secretagogues | Moderate | May preserve |
| GH fragments (AOD) | Uncertain | Unknown |
Evidence Hierarchy
- Strong evidence: Semaglutide, tirzepatide (body comp data)
- Limited evidence: GHRPs. The MK-677 trial result is described separately above.
- Insufficient evidence: AOD-9604, GHRH peptides
Tesamorelin’s indicated-population visceral-fat result, described above, is a separate endpoint and population; it is not ranked here against general fat-loss research.
Research Limitations
- Many studies report weight, not body composition
- DEXA data not always available
- Short-term studies may miss rebound
- AOD-9604 development discontinued for lack of efficacy
Peptides Studied for Fat Loss
Important Disclaimer
This page summarizes research findings and does not constitute medical advice. The peptides listed may or may not have regulatory approval. Always consult a qualified healthcare provider before making any health decisions.