Data Asset

GLP-1 Side Effect Incidence Rates From Major Trials

This data page compiles the side-effect percentages reported in major GLP-1 and tirzepatide trial tables into one trial-by-trial reference. Use it to compare how often common adverse events were reported in each dose arm and comparator group.

Coverage matches the audited GLPA-122 matrix: STEP 1-4, SURMOUNT 1-4, SURPASS 1-5, PIONEER 1-5 and 7-10, plus SUSTAIN 1-7. PIONEER 6 is intentionally omitted because its safety reporting structure does not match the row-level matrix. Blank cells mean the trial report did not provide a clean arm-level percentage for that tracked event in the reconstructed source package.

Methodology

How to read this matrix

Key Takeaways

What stands out in the recovered trial package

Master Matrix

Side effects as rows, trial arms as columns

Side effect STEP 1: Semaglutide 2.4 mg C1 STEP 1: Placebo C1 STEP 2: Semaglutide 2.4 mg C2 STEP 2: Semaglutide 1.0 mg C2 STEP 2: Placebo C2 STEP 3: Semaglutide 2.4 mg C3 STEP 3: Placebo C3 STEP 4: Continued semaglutide 2.4 mg C4 STEP 4: Switched to placebo C4 SURMOUNT-1: Tirzepatide 5 mg C6 SURMOUNT-1: Tirzepatide 10 mg C6 SURMOUNT-1: Tirzepatide 15 mg C6 SURMOUNT-1: Placebo C6 SURMOUNT-2: Tirzepatide 10 mg C7 SURMOUNT-2: Tirzepatide 15 mg C7 SURMOUNT-2: Placebo C7 SURMOUNT-3: Tirzepatide MTD (10 or 15 mg) C8 SURMOUNT-3: Placebo C8 SURMOUNT-4: Continued tirzepatide MTD (10 or 15 mg) C9 SURMOUNT-4: Switched to placebo C9 SURPASS-1: Tirzepatide 5 mg C10 SURPASS-1: Tirzepatide 10 mg C10 SURPASS-1: Tirzepatide 15 mg C10 SURPASS-1: Placebo C10 SURPASS-2: Tirzepatide 5 mg C11 SURPASS-2: Tirzepatide 10 mg C11 SURPASS-2: Tirzepatide 15 mg C11 SURPASS-2: Semaglutide 1 mg C11 SURPASS-3: Tirzepatide 5 mg C12 SURPASS-3: Tirzepatide 10 mg C12 SURPASS-3: Tirzepatide 15 mg C12 SURPASS-3: Insulin degludec C12 SURPASS-4: Tirzepatide 5 mg C13 SURPASS-4: Tirzepatide 10 mg C13 SURPASS-4: Tirzepatide 15 mg C13 SURPASS-4: Insulin glargine C13 SURPASS-5: Tirzepatide 5 mg C14 SURPASS-5: Tirzepatide 10 mg C14 SURPASS-5: Tirzepatide 15 mg C14 SURPASS-5: Placebo C14 PIONEER 1: Oral semaglutide 3 mg C15 PIONEER 1: Oral semaglutide 7 mg C15 PIONEER 1: Oral semaglutide 14 mg C15 PIONEER 1: Placebo C15 PIONEER 2: Oral semaglutide 14 mg C16 PIONEER 2: Empagliflozin 25 mg C16 PIONEER 3: Oral semaglutide 3 mg C17 PIONEER 3: Oral semaglutide 7 mg C17 PIONEER 3: Oral semaglutide 14 mg C17 PIONEER 3: Sitagliptin 100 mg C17 PIONEER 4: Oral semaglutide 14 mg C18 PIONEER 4: Liraglutide 1.8 mg C18 PIONEER 4: Placebo C18 PIONEER 5: Oral semaglutide 14 mg C19 PIONEER 5: Placebo C19 PIONEER 7: Oral semaglutide flexible dose C20 PIONEER 7: Sitagliptin 100 mg C20 PIONEER 8: Oral semaglutide 3 mg C21 PIONEER 8: Oral semaglutide 7 mg C21 PIONEER 8: Oral semaglutide 14 mg C21 PIONEER 8: Placebo C21 PIONEER 9: Oral semaglutide 3 mg C22 PIONEER 9: Oral semaglutide 7 mg C22 PIONEER 9: Oral semaglutide 14 mg C22 PIONEER 9: Placebo C22 PIONEER 9: Liraglutide 0.9 mg C22 PIONEER 10: Oral semaglutide 3 mg C23 PIONEER 10: Oral semaglutide 7 mg C23 PIONEER 10: Oral semaglutide 14 mg C23 PIONEER 10: Dulaglutide 0.75 mg C23 SUSTAIN 1: Semaglutide 0.5 mg C24 SUSTAIN 1: Semaglutide 1.0 mg C24 SUSTAIN 1: Placebo C24 SUSTAIN 2: Semaglutide 0.5 mg C25 SUSTAIN 2: Semaglutide 1.0 mg C25 SUSTAIN 2: Sitagliptin 100 mg C25 SUSTAIN 3: Semaglutide 1.0 mg C26 SUSTAIN 3: Exenatide ER 2.0 mg C26 SUSTAIN 4: Semaglutide 0.5 mg C27 SUSTAIN 4: Semaglutide 1.0 mg C27 SUSTAIN 4: Insulin glargine C27 SUSTAIN 5: Semaglutide 0.5 mg C28 SUSTAIN 5: Semaglutide 1.0 mg C28 SUSTAIN 5: Placebo C28 SUSTAIN 6: Semaglutide 0.5 mg C29 SUSTAIN 6: Matched placebo (0.5 mg schedule) C29 SUSTAIN 6: Semaglutide 1.0 mg C29 SUSTAIN 6: Matched placebo (1.0 mg schedule) C29 SUSTAIN 7: Semaglutide 0.5 mg C30 SUSTAIN 7: Dulaglutide 0.75 mg C30 SUSTAIN 7: Semaglutide 1.0 mg C30 SUSTAIN 7: Dulaglutide 1.5 mg C30
Nausea 44.2%17.4%33.7%32.1%9.2%58.2%22.1%14.0%4.9%24.6%33.3%31.0%9.5%20%22%6%39.7%14.0%8.1%2.7%12%13%18%6%17.4%19.2%22.1%17.9%12%23%24%2%12%16%23%2%12.9%17.6%18.3%2.5%8.0%5.1%16.0%5.6%19.8%2.4%7.3%13.4%15.1%6.9%20%18%4%19.0%7.5%21%2%11.4%16.6%23.2%7.1%4%10%8%2%0%5%8%9%9%20.3%23.8%7.8%18%18%7%22.3%11.9%21.3%22.2%3.6%11.4%16.8%4.5%17.3%7.5%21.9%8.1%23%13%21%20%
Vomiting 24.8%6.6%21.8%16.2%2.7%27.3%10.8%10.3%3.0%8.3%10.7%12.2%1.7%11%13%3%18.1%1.4%5.7%1.2%3%2%6%2%6%8%10%8%6%9%10%1%5%8%9%2%6.9%7.6%12.5%2.5%2.9%4.6%6.9%2.2%7.3%1.7%2.8%6.0%9.0%4.1%9%5%2%11.7%1.2%6%1%6.0%7.7%9.9%3.8%2%1%7%2%3.9%6.9%1.6%8%10%3%7.2%6.2%6.6%10.3%3.1%6.1%11.5%3.0%9.4%4.3%10.9%2.9%10%4%10%10%
Diarrhea 31.5%15.9%21.3%20.9%11.9%36.1%22.1%14.4%7.1%18.7%21.2%23.0%7.3%20%22%9%31.0%9.2%10.7%4.8%12%14%12%8%13%16%16%13%15%17%16%4%13%20%22%4%12.1%12.6%20.8%10.0%8.6%5.1%5.1%2.2%9.3%3.2%9.7%11.4%12.3%7.9%15%11%8%10.4%3.7%9%3%8.7%12.2%14.9%6.0%8%2%6%2%4%2%2%8%6%12.5%10.8%2.3%13%13%7%11.4%8.4%16.3%19.2%4.4%4.5%6.9%1.5%13.1%11.6%11.3%6.7%14%8%14%18%
Constipation 23.4%9.5%17.4%14.9%5.5%36.9%24.5%11.6%6.3%16.8%17.1%11.7%5.8%8%9%4%23.0%6.8%6%5%7%1%4%5%7%4%5%4%4%<1%6.0%6.7%6.7%1.7%8%4%3%11.7%3.7%4.3%8.3%6.6%2.7%10%12%13%6%19%9%12%15%9%6.3%3.8%0.8%4%6%2%6.4%5.2%5%3%5%5%
Fatigue 12.8%7.4%7.0%3.1%
Hair loss 5.1%4.9%5.7%0.9%7.0%1.4%
Injection-site reaction 5.0%6.7%3.0%2.8%2.5%2.9%5.7%4.6%0.3%11.1%1.0%3%3%2%0%<1%2%2%2%<1%<1%<1%<1%3.4%2.5%6.7%0.8%1.2%22.0%4.5%0.8%3.6%1.5%1%1%2%3%
Pancreatitis 0.2%0.2%0.2%0.2%0%1%<1%0.3%0.3%0%0%0%0%0%0%0%0%0%0%<1%<1%<1%<1%0%0%0%0%0%0%0%0%0%<1%<1%0%0%0%0%0%0%0%0%0%1%<1%0%0.6%0%0%0%0%0%0.2%0%0.1%0.1%0%0%0%0%
Gallbladder events 2.6%1.2%0.2%0%0.7%0.8%1.7%1.0%0.8%1%1%1%0.7%0%0%0.9%1%0%0%0%<1%<1%<1%<1%0.9%0%0%0%2%1%0%2%2.3%0.8%0%<1%2%1%0.3%0.6%0%2.3%0.8%0%3.9%3.2%4.6%2.8%1%1%1%3%

Recovered Tables

Arm-level side-effect rates

STEP

4 trials

STEP 1

Citation 1 · PMID 33567185

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 2.4 mg 44.2%24.8%31.5%23.4%5.0%2.6%
Placebo 17.4%6.6%15.9%9.5%6.7%1.2%

STEP 2

Citation 2 · PMID 33667417

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 2.4 mg 33.7%21.8%21.3%17.4%3.0%0.2%
Semaglutide 1.0 mg 32.1%16.2%20.9%14.9%2.8%0%
Placebo 9.2%2.7%11.9%5.5%2.5%0.7%

STEP 3

Citation 3 · PMID 33625476

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 2.4 mg 58.2%27.3%36.1%36.9%12.8%
Placebo 22.1%10.8%22.1%24.5%7.4%

STEP 4

Citation 4 · PMID 33755728

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Continued semaglutide 2.4 mg 14.0%10.3%14.4%11.6%
Switched to placebo 4.9%3.0%7.1%6.3%

SURMOUNT

4 trials

SURMOUNT-1

Citation 6 · PMID 35658024

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 24.6%8.3%18.7%16.8%5.1%2.9%0.2%0.8%
Tirzepatide 10 mg 33.3%10.7%21.2%17.1%4.9%5.7%0.2%1.7%
Tirzepatide 15 mg 31.0%12.2%23.0%11.7%5.7%4.6%0.2%1.0%
Placebo 9.5%1.7%7.3%5.8%0.9%0.3%0.2%0.8%

SURMOUNT-2

Citation 7 · PMID 37385275

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 10 mg 20%11%20%8%0%1%
Tirzepatide 15 mg 22%13%22%9%1%1%
Placebo 6%3%9%4%<1%1%

SURMOUNT-3

Citation 8 · PMID 37840095

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide MTD (10 or 15 mg) 39.7%18.1%31.0%23.0%7.0%7.0%11.1%0.3%0.7%
Placebo 14.0%1.4%9.2%6.8%3.1%1.4%1.0%0.3%0%

SURMOUNT-4

Citation 9 · PMID 38078870

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Continued tirzepatide MTD (10 or 15 mg) 8.1%5.7%10.7%0%0%
Switched to placebo 2.7%1.2%4.8%0%0.9%

SURPASS

5 trials

SURPASS-1

Citation 10 · PMID 34186022

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 12%3%12%6%3%0%1%
Tirzepatide 10 mg 13%2%14%5%3%0%0%
Tirzepatide 15 mg 18%6%12%7%2%0%0%
Placebo 6%2%8%1%0%0%0%

SURPASS-2

Citation 11 · PMID 34170647

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 17.4%6%13%4%
Tirzepatide 10 mg 19.2%8%16%5%
Tirzepatide 15 mg 22.1%10%16%7%
Semaglutide 1 mg 17.9%8%13%4%

SURPASS-3

Citation 12 · PMID 34370970

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 12%6%15%<1%0%
Tirzepatide 10 mg 23%9%17%2%0%
Tirzepatide 15 mg 24%10%16%2%0%
Insulin degludec 2%1%4%2%0%

SURPASS-4

Citation 13 · PMID 34672967

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 12%5%13%5%<1%<1%<1%
Tirzepatide 10 mg 16%8%20%4%<1%<1%<1%
Tirzepatide 15 mg 23%9%22%4%<1%<1%<1%
Insulin glargine 2%2%4%<1%<1%<1%<1%

SURPASS-5

Citation 14 · PMID 35133415

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Tirzepatide 5 mg 12.9%6.9%12.1%6.0%3.4%0%0.9%
Tirzepatide 10 mg 17.6%7.6%12.6%6.7%2.5%0%0%
Tirzepatide 15 mg 18.3%12.5%20.8%6.7%6.7%0%0%
Placebo 2.5%2.5%10.0%1.7%0.8%0%0%

PIONEER

9 trials

PIONEER 1

Citation 15 · PMID 31186300

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 3 mg 8.0%2.9%8.6%0%
Oral semaglutide 7 mg 5.1%4.6%5.1%0%
Oral semaglutide 14 mg 16.0%6.9%5.1%0%
Placebo 5.6%2.2%2.2%0%

PIONEER 2

Citation 16 · PMID 31530666

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 14 mg 19.8%7.3%9.3%
Empagliflozin 25 mg 2.4%1.7%3.2%

PIONEER 3

Citation 17 · PMID 30903796

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 3 mg 7.3%2.8%9.7%
Oral semaglutide 7 mg 13.4%6.0%11.4%
Oral semaglutide 14 mg 15.1%9.0%12.3%
Sitagliptin 100 mg 6.9%4.1%7.9%

PIONEER 4

Citation 18 · PMID 31186120

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 14 mg 20%9%15%8%0%
Liraglutide 1.8 mg 18%5%11%4%<1%
Placebo 4%2%8%3%<1%

PIONEER 5

Citation 19 · PMID 31189517

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 14 mg 19.0%11.7%10.4%11.7%
Placebo 7.5%1.2%3.7%3.7%

PIONEER 7

Citation 20 · PMID 31189520

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide flexible dose 21%6%9%0%
Sitagliptin 100 mg 2%1%3%0%

PIONEER 8

Citation 21 · PMID 31530667

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 3 mg 11.4%6.0%8.7%4.3%
Oral semaglutide 7 mg 16.6%7.7%12.2%8.3%
Oral semaglutide 14 mg 23.2%9.9%14.9%6.6%
Placebo 7.1%3.8%6.0%2.7%

PIONEER 9

Citation 22 · PMID 32333875

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 3 mg 4%8%10%
Oral semaglutide 7 mg 10%2%12%
Oral semaglutide 14 mg 8%6%13%
Placebo 2%2%6%
Liraglutide 0.9 mg 0%4%19%

PIONEER 10

Citation 23 · PMID 32333876

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Oral semaglutide 3 mg 5%2%2%9%0%2%
Oral semaglutide 7 mg 8%1%2%12%0%1%
Oral semaglutide 14 mg 9%7%8%15%0%0%
Dulaglutide 0.75 mg 9%2%6%9%0%2%

SUSTAIN

7 trials

SUSTAIN 1

Citation 24 · PMID 28110911

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 20.3%3.9%12.5%6.3%0%2.3%
Semaglutide 1.0 mg 23.8%6.9%10.8%3.8%0%0.8%
Placebo 7.8%1.6%2.3%0.8%0%0%

SUSTAIN 2

Citation 25 · PMID 28385659

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 18%8%13%4%1%<1%
Semaglutide 1.0 mg 18%10%13%6%<1%2%
Sitagliptin 100 mg 7%3%7%2%0%1%

SUSTAIN 3

Citation 26 · PMID 29246950

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 1.0 mg 22.3%7.2%11.4%6.4%1.2%
Exenatide ER 2.0 mg 11.9%6.2%8.4%5.2%22.0%

SUSTAIN 4

Citation 27 · PMID 28344112

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 21.3%6.6%16.3%0.6%0.3%
Semaglutide 1.0 mg 22.2%10.3%19.2%0%0.6%
Insulin glargine 3.6%3.1%4.4%0%0%

SUSTAIN 5

Citation 28 · PMID 29688502

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 11.4%6.1%4.5%0%2.3%
Semaglutide 1.0 mg 16.8%11.5%6.9%0%0.8%
Placebo 4.5%3.0%1.5%0%0%

SUSTAIN 6

Citation 29 · PMID 27633186

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 17.3%9.4%13.1%4.5%0.2%3.9%
Matched placebo (0.5 mg schedule) 7.5%4.3%11.6%0.8%0%3.2%
Semaglutide 1.0 mg 21.9%10.9%11.3%3.6%0.1%4.6%
Matched placebo (1.0 mg schedule) 8.1%2.9%6.7%1.5%0.1%2.8%

SUSTAIN 7

Citation 30 · PMID 29397376

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Arm NauseaVomitingDiarrheaConstipationFatigueHair lossInjection-site reactionPancreatitisGallbladder events
Semaglutide 0.5 mg 23%10%14%5%1%0%1%
Dulaglutide 0.75 mg 13%4%8%3%1%0%1%
Semaglutide 1.0 mg 21%10%14%5%2%0%1%
Dulaglutide 1.5 mg 20%10%18%5%3%0%3%

Cite this page

GLP-1 Answers. GLP-1 Side Effect Incidence Rates From Major Trials. Updated 2026-04-20. Accessed 2026-04-20. https://www.glp1answers.org/data/glp1-side-effect-rates

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