Last updated: May 18, 2026
Fat loss vs weight loss
Distinction matters: weight loss includes water, glycogen, lean mass, and fat. Fat loss specifically refers to reduction of adipose tissue. The best fat loss interventions preserve lean mass while reducing body fat percentage.
Top peptides ranked by evidence
1. Tirzepatide (Zepbound, Mounjaro)
~21% mean body weight loss in SURMOUNT-1. ~70-80% of that is fat tissue based on DEXA studies. The dual GLP-1/GIP mechanism produces the largest evidence-based fat reduction.
2. Semaglutide (Wegovy, Ozempic)
~15% mean body weight loss in STEP 1. Body composition data confirms most weight reduction is fat. SELECT trial added cardiovascular benefit.
3. Retatrutide (investigational)
~24% in Phase 2 — even larger than tirzepatide. Phase 3 ongoing. Triple-agonist mechanism (adds glucagon receptor) increases energy expenditure beyond appetite reduction.
4. Tesamorelin (Egrifta)
FDA-approved specifically for visceral (intra-abdominal) fat reduction in HIV-associated lipodystrophy. Mean visceral fat reduction ~15-20% in clinical trials. Does not produce general body weight loss.
5. CJC-1295 + Ipamorelin
Modest body recomposition (~2-4% body fat reduction over 12 weeks) through indirect GH/IGF-1 elevation. Not a primary fat loss intervention but supports body composition.
6. AOD9604
Research peptide marketed as targeting fat metabolism without GH side effects. Phase 2b human trial (2006) failed to show clinically significant weight loss. Mechanism is well-characterized but human efficacy weak.
7. HGH Fragment 176-191
Similar to AOD9604. Rodent evidence of lipolysis; human evidence is sparse.
Mechanism categories
| Mechanism | Peptides | Effect type |
|---|---|---|
| Appetite reduction (central) | Semaglutide, Tirzepatide, Retatrutide | Reduced caloric intake |
| Energy expenditure increase | Retatrutide (glucagon agonism), Tesamorelin (mild) | Increased basal metabolic rate |
| Selective lipolysis | AOD9604, HGH Fragment | Direct fat tissue effect (weak evidence) |
| Visceral fat targeting | Tesamorelin | GH-mediated visceral lipolysis |
| Body composition shift | CJC-1295/Ipamorelin, IGF-1 LR3 | Indirect via GH/IGF-1 |
Why GLP-1 agonists dominate
The GLP-1 class produces fat loss through multiple coordinated mechanisms (appetite, gastric emptying, glucose handling, central reward circuits) that together produce sustained caloric restriction. Other peptide classes lack this multi-mechanism profile.
Combination protocols
Common research-community pairings:
- GLP-1 + GH peptides (semaglutide/tirzepatide + CJC-1295/Ipamorelin) for fat loss with lean mass preservation
- GLP-1 + Tesamorelin specifically for visceral fat
Do AOD9604 and HGH Fragment actually work for fat loss?<br />
Weak human evidence. Published Phase 2b trials of AOD9604 failed to show clinical significance vs placebo. Mechanism is plausible but human efficacy is poorly supported.
Can peptides target stomach fat specifically?<br />
Tesamorelin is FDA-approved for visceral (intra-abdominal) fat reduction. Other peptides reduce fat proportionally — they don’t target specific body regions.
How does fat loss with peptides compare to anabolic steroids?<br />
Different mechanisms. Anabolic steroids primarily promote lean mass and indirectly reduce fat. GLP-1 peptides directly reduce caloric intake. Effect sizes for fat loss are comparable between top GLP-1 drugs and steroid protocols.
Are these the only options?<br />
For evidence-based fat loss interventions, FDA-approved GLP-1 drugs are the gold standard. Other peptide classes have supportive but not primary roles in fat loss protocols.