Semaglutide vs Tirzepatide vs Retatrutide: which GLP-1 compound is right for your research?
April 2026 · 8 min read · Bangkok Peptide Center
Three compounds, one conversation
The GLP-1 conversation has exploded globally over the last two years. Semaglutide, sold as Ozempic and Wegovy, put the entire category on the map. Tirzepatide followed with stronger data. Now Retatrutide is generating serious clinical interest with results that outperform both.
For researchers in Bangkok, all three compounds are accessible locally with same-day delivery — something that simply doesn’t exist in most cities. But understanding the differences between them is essential before designing any research protocol. This guide breaks down exactly how they differ, what the data shows, and which compound suits which research focus.
What makes these compounds different at the receptor level
All three work on the GLP-1 (glucagon-like peptide-1) receptor, which regulates appetite, gastric emptying, and insulin secretion. The key difference is how many additional receptors each compound targets.
Semaglutide
Single agonist. Targets GLP-1 receptor only. The active compound in Ozempic and Wegovy. Most clinical data of the three.
Tirzepatide
Dual agonist. Targets GLP-1 and GIP receptors simultaneously. Active compound in Mounjaro and Zepbound. Stronger metabolic effects than semaglutide.
Retatrutide
Triple agonist. Targets GLP-1, GIP, and glucagon receptors simultaneously. Most potent of the three. Currently in Phase 3 trials.
The progression is straightforward: each compound adds another receptor target, and each additional target amplifies the metabolic effect. More receptor pathways means more mechanisms working simultaneously.
What the clinical trials actually showed
Semaglutide showed approximately 15% body weight reduction in the STEP trials over 68 weeks at the 2.4mg weekly dose. This was a landmark result that drove enormous adoption of the branded product worldwide.
Tirzepatide outperformed semaglutide in head-to-head research. The SURMOUNT-1 trial showed up to 22.5% body weight reduction at the 15mg dose over 72 weeks, making it significantly more effective than semaglutide for metabolic research outcomes.
Retatrutide produced the most striking Phase 2 data of any compound in this class. At the 12mg dose over 48 weeks, researchers observed up to 24.2% body weight reduction — the highest figure ever recorded for a non-surgical weight intervention in a Phase 2 trial. Phase 3 data is currently being collected.
Retatrutide’s Phase 2 data produced weight reduction figures that had never been seen before in this class of research. The question Phase 3 is answering is whether those results hold at scale.
Direct comparison
| Feature | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Receptor targets | GLP-1 | GLP-1 + GIP | GLP-1 + GIP + Glucagon |
| Phase 2 weight reduction | ~15% | ~22.5% | ~24.2% |
| Clinical stage | FDA approved | FDA approved | Phase 3 trials |
| Branded equivalent | Ozempic / Wegovy | Mounjaro / Zepbound | None yet |
| Available in Bangkok | Not stocked | Yes — ฿2,900 | Yes — ฿3,100 |
How to choose between the three compounds
Semaglutide has the longest research history and the most published human data. For researchers who want the most studied compound in this class, it remains the benchmark. Bangkok Peptide Center does not currently stock semaglutide but we can source it on request — message us on WhatsApp.
Tirzepatide is the established step up from semaglutide. Head-to-head data shows it outperforms semaglutide consistently, and it has full FDA approval with a substantial body of Phase 3 data. For researchers wanting a well-documented dual agonist, Tirzepatide is the logical choice. Available now at Bangkok Peptide Center with same-day delivery.
Retatrutide represents the cutting edge of this research area. Its Phase 2 data is the strongest ever recorded in this compound class and it is the only triple agonist currently in late-stage clinical development. For researchers interested in the most potent metabolic peptide currently under study, Retatrutide is the compound to watch. Available now at Bangkok Peptide Center with same-day delivery.
GLP-1 research in Bangkok
Bangkok is one of the few cities in the world where researchers can access Tirzepatide and Retatrutide locally with same-day delivery, verified purity, and Certificate of Analysis documentation. No customs delays, no overseas shipping uncertainty, no quality questions. Bangkok Peptide Center stocks both compounds at 99%+ purity with free bacteriostatic water and needles included with every order.
Order GLP-1 research peptides in Bangkok
Tirzepatide and Retatrutide available now. 99%+ purity. Same-day delivery. Free water and needles included.
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