Retatrutide vs FGL
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
Retatrutide
Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors. Phase 2 trials showed unprecedented weight loss of up to 24% at 48 weeks, making it potentially the most effective obesity treatment studied.
Full details →FGL
FGL (FG Loop) is a synthetic peptide that mimics the neural cell adhesion molecule (NCAM) FG loop region. It promotes neuroplasticity and has shown cognitive-enhancing effects in research.
Full details →Side-by-Side Comparison
| Aspect | Retatrutide | FGL |
|---|---|---|
| Mechanism | Triple receptor activation provides complementary metabolic effects: GLP-1 and GIP reduce appetite and improve insulin sensitivity, while glucagon receptor activation increases energy expenditure and promotes hepatic fat oxidation. | Binds to FGFR1 (fibroblast growth factor receptor 1) to activate downstream signaling cascades that promote neurite outgrowth, synaptic plasticity, and neuronal survival. |
| Typical Dosage | Clinical trials used doses from 1mg to 12mg weekly. Optimal dosing still being determined in ongoing Phase 3 trials. | Research protocols have used subcutaneous doses ranging from 1-10mg. Intranasal administration also studied. Optimal dosing not established. |
| Administration | Subcutaneous injection once weekly. Currently only available through clinical trials - not yet FDA approved. | Subcutaneous injection or intranasal administration. Research compound with limited human dosing data. |
| Side Effects | Similar GI effects to other incretin-based therapies: nausea, diarrhea, vomiting, constipation. Dose-dependent severity. | Limited human data available. Animal studies show good tolerability. |
| Best For |