2026-05-12

What we know about retatrutide (and what we don't)

Retatrutide is a triple agonist: GLP-1, GIP, and glucagon in one molecule. Eli Lilly is developing it. Still Phase 3. Not FDA-approved. Not at your pharmacy.

Thousands of people are already using it.

What we know. Phase 2 (NEJM, 2023): 24% body weight loss in 48 weeks at 12mg. More than tirzepatide. More than semaglutide. Side effects: nausea, vomiting, fatigue. The classic incretin pattern. At higher doses, tachycardia.

What's missing. Long-term data. The Phase 3 (TRIUMPH) is running now. Full results: 2026–2027. The question isn't whether it works. It's what shows up at two years, at five, in real people.

What's happening in the meantime. On Reddit, Telegram, X DMs — people buying "research use only" vials and dosing themselves. Some follow the Phase 2 protocol. Others freelance. Certificates of Analysis vary: some suppliers publish independent lab results, others publish nothing.

If you're taking it. Read the paper first — Jastreboff et al., NEJM 2023. The most-studied titration starts at 2mg, escalating every four weeks. Side effects show up in the first two weeks after each step.

If you're buying it. Don't buy from anyone without a COA verified by an independent lab. The difference between a clean peptide and a contaminated one isn't noticeable until you're already reacting badly.

Bukowski isn't your doctor. But he read the paper.