What the studies show
TRIUMPH-4 enrolled adults with obesity and knee osteoarthritis: WOMAC pain fell by up to 4.5 points (75.8%) vs 2.4 (40.3%) on placebo. Weight loss likely explains much of it; not yet peer-reviewed.
Human trials exist and mostly agree, but there are too few of them, they are too small, or one big one is still reading out. Expect the grade to move.
- 1Eli Lilly. Retatrutide delivered weight loss of up to an average of 71.2 lbs along with substantial relief from osteoarthritis pain in first successful phase 3 trial (TRIUMPH-4).Press release, 11 Dec 2025445 adults, 68 weeks. Topline; not peer-reviewed.
In context
Retatrutide is an investigational once-weekly peptide that activates three receptors at once: GIP, GLP-1 and glucagon. Phase 3 topline results announced in December 2025 and May 2026 report average weight loss of about 26–29% at 68–80 weeks — the largest yet for a single drug — with high rates of nausea and more people stopping for side effects than on placebo. The full data are not yet peer-reviewed. It is not approved anywhere, and no legitimate supply exists outside clinical trials.
Retatrutide is investigational. Legal status differs by country — see the regulation section or the jurisdiction pages.
Questions
Is Retatrutide proven to help with knee osteoarthritis pain?
What studies are behind the grade?
Is Retatrutide approved for this?
Other outcomes for Retatrutide
- BBody weight1 phase 2 RCT published; 2 phase 3 RCTs topline
- BGI side effectsadversePhase 2 + phase 3 topline
- BDysesthesia (skin sensation changes)adversePhase 3 topline
Reviewed 2 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →