Last updated: June 3, 2026
Most common (>10%)
- Nausea — 25-30% (slightly higher than semaglutide in equivalent titration)
- Diarrhea — 20%
- Decreased appetite — 15%+
- Vomiting — 15%
- Constipation — 10-15%
- Dyspepsia, abdominal pain
Compared to semaglutide
SURPASS-2 head-to-head showed tirzepatide and semaglutide had similar overall GI tolerability, with tirzepatide producing slightly more nausea in early titration. By week 8-12, both drugs had similar tolerability profiles.
Less common
- Injection-site reactions (mild)
- Hair loss reported in SURMOUNT trials (~5%, more common than placebo)
- Hypersensitivity reactions
- Hypoglycemia (with insulin/sulfonylureas)
Rare but serious
- Acute pancreatitis
- Cholelithiasis / cholecystitis
- Acute kidney injury (typically from dehydration via vomiting)
- Severe gastroparesis
- Retinopathy progression (in pre-existing T2D retinopathy)
- Theoretical thyroid C-cell tumor risk (rodent data)
Boxed warnings (same as semaglutide)
- Contraindicated in personal/family history of MTC
- Contraindicated in MEN2
Tirzepatide-specific notes
Heart rate elevation: Mean +2-4 bpm increase in resting HR — clinical significance unclear.
SURMOUNT-OSA cardiac data: Tirzepatide improved obstructive sleep apnea AHI and reduced cardiovascular risk markers in adults with OSA + obesity.
Are tirzepatide side effects worse than semaglutide?<br />
Slightly more pronounced in early titration, but similar overall tolerability by week 8-12 of consistent dosing.
Does tirzepatide cause hair loss?<br />
SURMOUNT trials reported ~5% hair loss vs ~1% placebo — likely related to rapid weight loss rather than direct drug effect. Resolves after rate of weight loss slows.
Can tirzepatide cause heart problems?<br />
Mean resting HR increase of 2-4 bpm. No increased MACE in completed trials. SURMOUNT-OSA showed cardiovascular benefit in OSA + obesity population.
How fast do side effects resolve?<br />
Most GI symptoms improve over 4-8 weeks at each dose step. Slower titration reduces severity.
Related guides: Semaglutide vs Tirzepatide · Semaglutide side effects · Retatrutide guide