📊 Peptide Side-Effect Explorer

Pick a symptom to see every published Phase 2/3 trial that reports it — sorted by frequency, with dose, population, and source citations.

1. Pick a symptom
Chips are sorted by the highest reported frequency across any trial — the ones at the top show up most often.
Trials reporting
5
Unique peptides
3
Mean frequency
11%
Range
7–16%

Trials reporting Headache

Peptide Trial Dose & duration Population Frequency Source
Semaglutide STEP-1
N=1,961 · 2021
2.4 mg SC weekly
68 weeks
Obesity, no diabetes
16.1%
NEJM 2021
Retatrutide TRIUMPH-1
N=2,339 · 2026
12 mg SC weekly
104 weeks
Obesity, no diabetes
12.0%
AJMC 2026
Semaglutide REDEFINE-1
N=3,417 · 2026
2.4 mg / 2.4 mg SC weekly
68 weeks
Obesity
11.0%
HCPLive 2026
Semaglutide STEP-2
N=1,210 · 2021
2.4 mg SC weekly
68 weeks
Obesity + T2D
9.8%
Lancet 2021
Tirzepatide SURMOUNT-1
N=2,539 · 2022
15 mg SC weekly
72 weeks
Obesity, no diabetes
7.3%
NEJM 2022
About the data. Frequencies are drawn from published Phase 2/3 trial reports — primarily GLP-1 class (semaglutide, tirzepatide, retatrutide) where head-to-head placebo-controlled data is available. Absence of a symptom here means it was not a prespecified adverse event in that trial, not that it never occurs. Rare and long-tail events are under-represented.
v1 coverage: 9 distinct symptoms across 3 peptides and 7 landmark trials. Non-GLP-1 compounds (BPC-157, TB-500, GHK-Cu, etc.) are not yet included — their side-effect data comes mostly from case reports and preclinical work rather than randomised trials. If you have a specific trial you'd like us to code, let us know.