Generic name
semaglutide
tirzepatide
Manufacturer
Novo Nordisk
Eli Lilly
Drug class
GLP-1 receptor agonist
Dual GIP / GLP-1 receptor agonist
FDA approved
December 2017
November 2023
Indication
Type 2 diabetes (adults)
Chronic weight management (adults)
Dose schedule
Subcutaneous injection · Once weekly
Subcutaneous injection · Once weekly
Available doses
0.25 mg · 0.5 mg · 1 mg · 2 mg
2.5 mg · 5 mg · 7.5 mg · 10 mg · 12.5 mg · 15 mg
Mechanism
Semaglutide is a GLP-1 analog with 94% homology to native human GLP-1. It binds the GLP-1 receptor, augmenting glucose-dependent insulin secretion, suppressing glucagon, slowing gastric emptying, and reducing appetite via central nervous system pathways.
Tirzepatide is a first-in-class single molecule that activates both the GIP and GLP-1 receptors. The dual incretin action slows gastric emptying and reduces appetite via central nervous system pathways while improving glucose handling — producing larger average weight loss than single GLP-1 agonists in its obesity trials.
Common side effects
Nausea (15–20%), diarrhea (8–9%), vomiting (5–9%) — most resolve within weeks
Nausea, diarrhea, vomiting, constipation — mostly mild, ease after titration
Cost range
$25 – $1,150 / month depending on coverage
$25 – $1,300 / month depending on coverage
This comparison is for education only and is not medical advice. Ozempic and Zepbound are prescription medicines with distinct FDA-approved indications. Whether either is appropriate for you — and at what dose — is a decision for a licensed clinician.