Mechanism difference
Semaglutide is a GLP-1 receptor agonist. Tirzepatide activates both GIP and GLP-1 pathways. That dual-pathway mechanism is one reason tirzepatide is often discussed separately from traditional GLP-1-only therapy.
Trial evidence
In the SURMOUNT-1 obesity trial, adults receiving higher-dose tirzepatide achieved average weight reductions around 19.5% to 20.9% at 72 weeks for the 10 mg and 15 mg groups. In a 2025 head-to-head NEJM trial, tirzepatide produced greater average body-weight reduction than semaglutide 2.4 mg at 72 weeks in adults with obesity without diabetes.
What this means for cost comparison
Medication efficacy should not be separated from total cost, dose escalation, side-effect support, and long-term maintenance. A provider with predictable higher-dose pricing may become more attractive as patients move from starter doses to maintenance doses, which is why NexLife’s flat-rate positioning is important in affordability comparisons.