How to Calculate GLP-1 Side Effect Risk

What is GLP-1 Side Effect Risk?

The GLP-1 Side Effect Risk Score calculator estimates your likelihood of experiencing common gastrointestinal and other adverse effects from GLP-1 receptor agonist therapy. Using clinical trial adverse event data, it generates a personalized risk profile based on medication, dose, and patient factors.

Formula

Side Effect Risk Score = Base Incidence Rate × Patient Risk Multiplier (age, GI history, dose speed)

B_inc: Base Incidence Rate (%) — Clinical trial reported side effect incidence for selected medication and dose
RM: Risk Multiplier (factor) — Patient-specific modifier based on age, GI history, and concurrent medications
D_speed: Titration Speed (standard/fast/slow) — Rate of dose escalation relative to FDA schedule
GI_hx: GI History (yes/no) — History of GERD, gastroparesis, IBS, or gallbladder disease

Step-by-Step Guide

1Select your GLP-1 medication and current or planned dose
2Enter relevant medical history: prior GI issues, gastroparesis, gallbladder disease
3Indicate your titration speed (standard, accelerated, or delayed)
4View risk percentages for nausea, vomiting, diarrhea, constipation, and other side effects

Worked Examples

Input

Semaglutide 2.4 mg, history of GERD, standard titration, age 45

Result

Nausea risk: 48% (vs. 44% baseline from STEP 1), Vomiting: 28%, Diarrhea: 32%, Constipation: 26%. Overall GI event risk: HIGH. GERD history increases nausea risk by ~10%.

Input

Tirzepatide 5 mg, no GI history, standard titration, age 30

Result

Nausea risk: 20% (lower dose), Vomiting: 8%, Diarrhea: 14%. Overall GI event risk: LOW-MODERATE. Most side effects are mild and resolve within 4-8 weeks.

Common Mistakes to Avoid

✕Confusing severity with frequency — while nausea is common (40-50%), severe nausea requiring discontinuation occurs in only 4-7% of patients
✕Not recognizing that most GI side effects peak during dose escalation and decrease at stable maintenance doses
✕Ignoring rare but serious risks like pancreatitis (0.1-0.3%) and gallbladder events (1-2%)

Frequently Asked Questions

What are the most common side effects of GLP-1 medications?

Nausea (40-50%), diarrhea (25-35%), vomiting (20-30%), constipation (20-25%), and abdominal pain (10-20%) are most common. Most are mild to moderate, occur during dose titration, and resolve within 4-8 weeks. Fatigue, headache, and dizziness also occur in 5-15% of patients.

Are there any serious risks with GLP-1 medications?

Rare but important risks include acute pancreatitis (0.1-0.3%), gallbladder events including cholelithiasis (1-2%), and a theoretical risk of medullary thyroid carcinoma (seen in rodents; no confirmed human cases). GLP-1s are contraindicated in patients with personal or family history of medullary thyroid cancer or MEN2 syndrome.

Do side effects go away over time?

Yes, for most patients. GI side effects are worst during the first 4-8 weeks of each dose titration step and typically diminish at a stable maintenance dose. Approximately 80% of patients who experience nausea report it resolving or becoming mild within 2 months of reaching their target dose.

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