The short answer
Both are GLP-1 receptor agonists, and liraglutide is semaglutide’s predecessor: its half-life of about 13 hours means a daily shot, where semaglutide’s of about a week allows one a week. Both are FDA-approved, liraglutide as Victoza and Saxenda, semaglutide as Ozempic and Wegovy. Commonly reported: appetite drops on both, less dramatically on liraglutide.
Side by side
| Compared | Liraglutide | Semaglutide |
|---|---|---|
| Category | Metabolic & GLP-1 | Metabolic & GLP-1 |
| Also known as | Victoza, Saxenda, Liraglutide injection | Ozempic, Wegovy |
| What it is | The predecessor to semaglutide: a GLP-1 receptor agonist that reduces appetite and improves blood sugar control, given as a daily injection rather than weekly. | A GLP-1 receptor agonist that mimics a gut hormone your body releases after eating: it reduces appetite and slows stomach emptying. |
| How it works | GLP-1 receptor agonist and predecessor to semaglutide. Stimulates insulin secretion, reduces glucagon, slows gastric emptying, and reduces appetite. Shorter half-life than semaglutide requiring daily dosing. FDA approved for type 2 diabetes (Victoza) and obesity (Saxenda). The labels step the dose up from 0.6 mg to minimize GI side effects. | GLP-1 receptor agonist that reduces appetite, slows gastric emptying, and improves glucose metabolism. FDA-approved for T2DM and obesity. Titrate dose slowly to minimize GI side effects. |
| Commonly reported | Appetite drops and meals end sooner, though less dramatically than on semaglutide or tirzepatide, with nausea during the climb to 3 mg. FDA-approved for diabetes (Victoza) and obesity (Saxenda), with one of the longest track records of any GLP-1 drug. | The constant background thoughts about food ("food noise") go quiet and portions shrink without effort, with nausea worst in the first days after each dose step. FDA-approved for type 2 diabetes, weight management, heart-risk reduction and MASH, with about 15% average weight loss at 68 weeks in its main trial. |
| Studied range | FDA label: 0.6–3 mg, starting dose 0.6 mg. | FDA label: 0.25–2.4 mg, starting dose 0.25 mg. |
| How often | Daily SubQ | Weekly SubQ |
| Half-life | ~13 hours | ~1 week (FDA label) |
| Route | SubQ injection | SubQ injection |
| Typical run | FDA-approved for daily use. Community uses continuously or until goal reached. | FDA-approved for ongoing use. Community uses indefinitely or until goal weight reached, then tapers. |
| Evidence | Established: clinical trials or FDA-approved use exists | Established: clinical trials or FDA-approved use exists |
| Common side effects | Nausea, vomiting, diarrhea, constipation, pancreatitis risk, thyroid C-cell tumor risk (animal data) | Nausea, vomiting, diarrhea, constipation, decreased appetite, fatigue, pancreatitis risk |
- Category
- LiraglutideMetabolic & GLP-1
- SemaglutideMetabolic & GLP-1
- Also known as
- LiraglutideVictoza, Saxenda, Liraglutide injection
- SemaglutideOzempic, Wegovy
- What it is
- LiraglutideThe predecessor to semaglutide: a GLP-1 receptor agonist that reduces appetite and improves blood sugar control, given as a daily injection rather than weekly.
- SemaglutideA GLP-1 receptor agonist that mimics a gut hormone your body releases after eating: it reduces appetite and slows stomach emptying.
- How it works
- LiraglutideGLP-1 receptor agonist and predecessor to semaglutide. Stimulates insulin secretion, reduces glucagon, slows gastric emptying, and reduces appetite. Shorter half-life than semaglutide requiring daily dosing. FDA approved for type 2 diabetes (Victoza) and obesity (Saxenda). The labels step the dose up from 0.6 mg to minimize GI side effects.
- SemaglutideGLP-1 receptor agonist that reduces appetite, slows gastric emptying, and improves glucose metabolism. FDA-approved for T2DM and obesity. Titrate dose slowly to minimize GI side effects.
- Commonly reported
- LiraglutideAppetite drops and meals end sooner, though less dramatically than on semaglutide or tirzepatide, with nausea during the climb to 3 mg. FDA-approved for diabetes (Victoza) and obesity (Saxenda), with one of the longest track records of any GLP-1 drug.
- SemaglutideThe constant background thoughts about food ("food noise") go quiet and portions shrink without effort, with nausea worst in the first days after each dose step. FDA-approved for type 2 diabetes, weight management, heart-risk reduction and MASH, with about 15% average weight loss at 68 weeks in its main trial.
- Studied range
- LiraglutideFDA label: 0.6–3 mg, starting dose 0.6 mg.
- SemaglutideFDA label: 0.25–2.4 mg, starting dose 0.25 mg.
- How often
- LiraglutideDaily SubQ
- SemaglutideWeekly SubQ
- Half-life
- Liraglutide~13 hours
- Semaglutide~1 week (FDA label)
- Route
- LiraglutideSubQ injection
- SemaglutideSubQ injection
- Typical run
- LiraglutideFDA-approved for daily use. Community uses continuously or until goal reached.
- SemaglutideFDA-approved for ongoing use. Community uses indefinitely or until goal weight reached, then tapers.
- Evidence
- LiraglutideEstablished: clinical trials or FDA-approved use exists
- SemaglutideEstablished: clinical trials or FDA-approved use exists
- Common side effects
- LiraglutideNausea, vomiting, diarrhea, constipation, pancreatitis risk, thyroid C-cell tumor risk (animal data)
- SemaglutideNausea, vomiting, diarrhea, constipation, decreased appetite, fatigue, pancreatitis risk
Typical run: Community practice — opinions vary. Not a clinical recommendation.
Week by week
Each entry’s cards by day window, as the compound pages show them. Day 1 is the day you start it.
Liraglutide
- Day 1–14 · 0.6 mg Starting dose — GI is the main thing
- Day 14–42 Titrating up — appetite really drops
- Day 42–168 Steady loss at target dose
- Day 168–365 Maintenance and long game
Semaglutide
- Day 1–28 · 0.25 mg Gut is adapting
- Day 29–56 · 0.5 mg Appetite shifts are real now
- Day 57–112 · 1 mg Clinically useful weight loss kicks in
- Day 113–140 · 1.7 mg Max submaximal step
- Day 141–364 · 2.4 mg Full dose — the working dose
- Day 365+ Plateau territory — new baseline
Questions people ask
How long do liraglutide and semaglutide last?
The half-life of liraglutide is ~13 hours. The half-life of semaglutide is ~1 week (FDA label).
How often are liraglutide and semaglutide taken?
Liraglutide: daily SubQ. Route: SubQ injection. Semaglutide: weekly SubQ. Route: SubQ injection.
How are liraglutide and semaglutide dosed in research?
The FDA label range for liraglutide is 0.6–3 mg, with a 0.6 mg starting dose. The FDA label range for semaglutide is 0.25–2.4 mg, with a 0.25 mg starting dose.
What are the common side effects of liraglutide and semaglutide?
For liraglutide, the library lists: nausea, vomiting, diarrhea, constipation, pancreatitis risk, thyroid C-cell tumor risk (animal data). For semaglutide: nausea, vomiting, diarrhea, constipation, decreased appetite, fatigue, pancreatitis risk.
Each one in full
PepVault for iPhone
Track either one in PepVault
Log every dose of liraglutide or semaglutide, with reminders on your schedule. 7 days free on the yearly plan for new subscribers.
