📊 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.

Nausea up to 44% Diarrhea up to 33% Vomiting up to 25% Constipation up to 25% Headache up to 16% Abdominal pain up to 14% Decreased appetite up to 12% Fatigue up to 11% Dyspepsia up to 10%

Trials reporting

Unique peptides

Mean frequency

19%

Range

11–25%

Trials reporting Constipation

Peptide	Trial	Dose & duration	Population	Frequency	Source
Retatrutide	TRIUMPH-1 N=2,339 · 2026	12 mg SC weekly 104 weeks	Obesity, no diabetes	25.0%	AJMC 2026
Semaglutide	STEP-1 N=1,961 · 2021	2.4 mg SC weekly 68 weeks	Obesity, no diabetes	24.1%	NEJM 2021
Tirzepatide	SURMOUNT-5 N=751 · 2026	Tirzepatide 15 mg vs Semaglutide 2.4 mg weekly 72 weeks	Obesity, no diabetes	22.1%	NEJM 2026
Semaglutide	SURMOUNT-5 N=751 · 2026	Tirzepatide 15 mg vs Semaglutide 2.4 mg weekly 72 weeks	Obesity, no diabetes	22.1%	NEJM 2026
Semaglutide	REDEFINE-1 N=3,417 · 2026	2.4 mg / 2.4 mg SC weekly 68 weeks	Obesity	19.0%	HCPLive 2026
Semaglutide	STEP-2 N=1,210 · 2021	2.4 mg SC weekly 68 weeks	Obesity + T2D	13.3%	Lancet 2021
Tirzepatide	SURMOUNT-1 N=2,539 · 2022	15 mg SC weekly 72 weeks	Obesity, no diabetes	11.7%	NEJM 2022
Semaglutide	EVOKE N=1,855 · 2026	14 mg oral daily 156 weeks	Mild cognitive impairment / early AD	11.0%	Lancet 2026

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.

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