Retatrutide

No brand yet · Eli Lilly. The largest weight loss ever recorded in a major obesity trial. Side effects, including an unusual skin sensitivity, are also the highest. US filing planned for Q1 2027.

Average weight loss

28.3%

Stopped for side effects

11.3%

Trial length

80 wk

Ranking score

6.6

TRIUMPH-1 results

Phase 3 · 80 weeks · 12 mg weekly
Adults with obesity, no diabetes (n=2,339)

Weight loss

28.3%

Nausea

42.4%

Vomiting

25.3%

Diarrhea

32.0%

Constipation

26.1%

Quit due to side effects

11.3%

n/r = not reported. Counting everyone who started, weight loss was 25%. Placebo group: 2.2%. Skin-sensation events (dysesthesia): 12.5%.

Worth knowing

Two-year extension (BMI 35+): about 30% average weight loss.
TRIUMPH-3 did not show a statistically clear heart-outcome benefit.

Next catalysts

Q1 2027 Eli Lilly submits retatrutide to the FDA (Company guidance)

~2028 Earliest likely US approval of retatrutide (standard review) (Our estimate)

6.6

GLP-1 Performance Index

Rank 2 of 6 ranked drugs

Stomach = (42.4 + 25.3 + 32.0 + 26.1) ÷ 4 = 31.5 Burden = 31.5 + 1 × 11.3 = 42.8 Index = 28.3 ÷ 42.8 × 10 = 6.62

At a glance

Company: Eli Lilly
Targets: GLP-1, GIP, Glucagon
Molecule: Peptide
Dosing: Injection, weekly
Status: Phase 3 complete

Compare with another drug

Sources

History

Jul 23, 2026
Retatrutide TRIUMPH-2 and TRIUMPH-3 read out; Lilly targets a Q1 2027 filing.
May 21, 2026
Retatrutide TRIUMPH-1: 28.3% average weight loss at 80 weeks.