Mounjaro vs Ozempic
The two most-discussed weight loss medications compared side by side. Mounjaro and Zepbound are brand names for tirzepatide. Ozempic and Wegovy are brand names for semaglutide. Same drugs, different names — we use the generic names below.
Quick read · 5 min
- •In the head-to-head SURMOUNT-5 trial, tirzepatide produced 20.2% average weight loss vs 13.7% for semaglutide
- •Semaglutide has proven cardiovascular benefit (20% reduction in major heart events in SELECT trial) — tirzepatide does not yet have this data
- •Semaglutide is available as both injection (~$1,350/mo) and pill (~$149/mo). Tirzepatide is injection only (~$1,086/mo via LillyDirect)
- •Side effect profiles are similar — nausea is most common, typically temporary
SURMOUNT-5 Trial Detail
In SURMOUNT-5, 751 adults with obesity were randomly assigned to either tirzepatide or semaglutide for 72 weeks. Both groups received the maximum approved dose. Tirzepatide produced 20.2% average weight loss. Semaglutide produced 13.7%. This was the first large trial to directly compare these two drugs head-to-head.
This is the most direct evidence we have for comparing these drugs. Both are highly effective. Tirzepatide showed higher weight loss in this comparison.
Weight Loss Comparison
Context: Both are effective. The difference of 6–7 percentage points translates to roughly 14–17 lbs for a 240 lb person. Individual results vary substantially.
Cardiovascular Evidence
Semaglutide
SELECT trial (published 2024) showed 20% reduction in major cardiovascular events (heart attack, stroke, cardiovascular death). This is robust evidence.
Tirzepatide
SURPASS-CVOT completed; results show non-inferiority for cardiovascular safety but do not yet establish cardiovascular benefit like SELECT.
Implication: If cardiovascular health is a priority, semaglutide has stronger evidence. Tirzepatide is still safe; the comparison data is not yet complete.
Form and Convenience
Tirzepatide
Injection only, once-weekly under the skin. No food timing restrictions.
Semaglutide
Both injection and daily oral pill (Wegovy, approved Dec 2025). Oral pill requires 30-minute fasting window before food (no water, no other drinks).
Context: The pill option with semaglutide is a major advantage for people with injection anxiety. Cost difference is dramatic ($149/mo for pill vs $1,350/mo for injection).
Cost Comparison
Major advantage: Oral semaglutide is dramatically cheaper and offers a pill option that was previously unavailable.
Side Effect Comparison
Both drugs
Nausea is most common side effect (40–50% in trials), usually in first 4–8 weeks, then subsides. Other GI effects (diarrhea, constipation) also common.
Tirzepatide
Slightly more reports of nausea in early phase but similar overall side effect profile.
Semaglutide
Well-established safety record with longer market history.
Context: Side effect severity varies widely by individual. Neither profile is dramatically different from the other.
Trade-Off Summary
Tirzepatide Profile
- ✓Higher average weight loss in head-to-head (20.2% vs 13.7%)
- ✓Once-weekly injection, no food timing restrictions
- ✓May offer food noise reduction reported by users
- ◆No proven cardiovascular benefit data yet
- ◆Injection only (no pill option)
- ◆Higher cost than semaglutide pill (~$1,086/mo via LillyDirect)
- ◆May require longer dose escalation
Semaglutide Profile
- ✓Proven cardiovascular benefit (SELECT trial, 20% reduction in major events)
- ✓Available as pill (~$149/mo) — most affordable GLP-1 option
- ✓Longest market history — extensive safety data
- ◆Slightly lower weight loss in head-to-head (13.7% vs 20.2%)
- ◆Oral pill has 30-minute fasting window (strict timing)
- ◆Injection is expensive (~$1,350/mo list price)
- ◆Less novel mechanism than dual agonists
These two drugs differ across weight loss, cardiovascular evidence, cost, and form. Neither is universally "better" — they have distinct clinical profiles. These factors may matter differently depending on individual circumstances, and can be discussed with a doctor in the context of a specific medical history.
Two oral GLP-1 pills are now FDA-approved: Oral Wegovy (semaglutide pill, ~16.6% weight loss, $149/month) and Foundayo (orforglipron, ~12.4% weight loss, no food restrictions).
See the Oral Wegovy vs Foundayo comparison →Not sure where to start? Our 2-minute quiz can help.
Take the quiz →Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: March 2026