What it is
Semaglutide is a long-acting GLP-1 receptor agonist studied for type-2 diabetes and obesity. The weekly obesity dose is 2.4 mg in the STEP program.
Evidence boundary
Human evidence exists for the studied indications.
Trial evidence
- PMID 42686906 — Late-life semaglutide treatment slows ageing and extends lifespan in female mice.
- PMID 42747817 — Efficacy and Safety of Semaglutide According to Frailty Status: A Post Hoc Analysis of the SELECT Randomized Clinical Trial.
- PMID 42657770 — Effects of Semaglutide versus Bariatric Surgery on Noninvasive Markers of Hepatic Steatosis and Fibrosis in Obesity with Type 2 Diabetes.
Preparation and measurement
Reconstitution: 10 mg vial + 1 mL BAC = 10 mg/mL.
Concentration matches.
Reference schedule
| Phase | Dose | Draw / measure | Frequency | Weekly total |
|---|---|---|---|---|
| Weeks 1–4 | 250 mcg | 2.5 U (0.025 mL) | Once weekly | 250 mcg/week |
| Weeks 5–8 | 500 mcg | 5 U (0.05 mL) | Once weekly | 500 mcg/week |
| Weeks 9–12 | 1 mg | 10 U (0.1 mL) | Once weekly | 1 mg/week |
| Weeks 13–16 | 1.7 mg | 17 U (0.17 mL) | Once weekly | 1.7 mg/week |
| Weeks 17+ | 2.4 mg | 24 U (0.24 mL) | Once weekly | 2.4 mg/week |
Weeks 1–4
- Dose
- 250 mcg
- Draw / measure
- 2.5 U (0.025 mL)
- Frequency
- Once weekly
- Weekly total
- 250 mcg/week
Weeks 5–8
- Dose
- 500 mcg
- Draw / measure
- 5 U (0.05 mL)
- Frequency
- Once weekly
- Weekly total
- 500 mcg/week
Weeks 9–12
- Dose
- 1 mg
- Draw / measure
- 10 U (0.1 mL)
- Frequency
- Once weekly
- Weekly total
- 1 mg/week
Weeks 13–16
- Dose
- 1.7 mg
- Draw / measure
- 17 U (0.17 mL)
- Frequency
- Once weekly
- Weekly total
- 1.7 mg/week
Weeks 17+
- Dose
- 2.4 mg
- Draw / measure
- 24 U (0.24 mL)
- Frequency
- Once weekly
- Weekly total
- 2.4 mg/week
Weekly totals apply only during the active phase.
Titration rules
- 0.25 mg weekly is the cautious start.
- 0.5 mg weekly is the next step.
- 1 mg weekly is the middle step.
- 1.7 mg weekly is the higher step.
- 2.4 mg weekly is the usual maintenance dose in obesity trials.
- Hold each step for 4 weeks before moving on.
Cycle length and breaks
Reassess after the main study window instead of inventing a break schedule.
What to monitor
- Weight-loss response
- HbA1c / glycemic response
- Blood pressure and lipids
- GI effects during escalation
- Appetite suppression
- Tolerability
- Do not read this as an approved label.
Practical rules
- Subcutaneous, once weekly.
- Rotate injection sites.
- Smaller meals and slower titration help with GI effects.
- Keep protein and resistance training in the plan if lean mass matters.