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Comparison

Semaglutide vs Liraglutide

Weekly semaglutide compared with daily liraglutide — same family, very different injection cadence and titration pattern.

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Field
Semaglutide
Liraglutide
Category
GLP-1
GLP-1
Common alias
GLP-1 agonist (Ozempic, Wegovy)
GLP-1 agonist (Saxenda, Victoza)
Example vial
5 mg + 2 mL BAC water
6 mg + 3 mL BAC water
Concentration
2.50 mg/mL
2.00 mg/mL
Example dose
0.25 mg
1.2 mg
Doses per week
1× / week
7× / week
Doses per vial (rounded down)
20
5
Approx vial duration
20.0 weeks
0.7 weeks

Semaglutide and Liraglutide both show up in the same conversations, but they aren't interchangeable. The table above lays the vial math side by side so you can see how concentration, doses-per-vial, and weekly cadence actually compare. The sections below walk through what each one is, how each is studied, and how each shows up in a tracked log — in plain English, no recommendations.

Tiebreakers

Where Semaglutide and Liraglutide actually diverge

SemaglutideLiraglutide
Cadence1/wk7/wk
Concentration on example2.50 mg/mL2.00 mg/mL
Math weeks per vial20.00.7
CategoryGLP-1GLP-1

Bolded values are the higher of the two on numeric rows. Same-value rows aren't a verdict — they're shared properties.

Semaglutide vs Liraglutide: the actual decision

Cadence is the headline difference here. Liraglutide is a daily subcutaneous shot; semaglutide is weekly. Both are GLP-1 agonists with the same broad mechanism, but the half-life difference (about 13 hours for liraglutide, about a week for semaglutide) drives almost every practical difference a reader will notice in a log. A liraglutide log has 7x the injection events of a semaglutide log over the same calendar window, which has real implications for adherence, scar tissue rotation, and the texture of side-effect tracking.

Trial data put semaglutide ahead on absolute weight loss in head-to-head comparisons — STEP-8 reported about 16 percent loss at 68 weeks for semaglutide 2.4 mg weekly versus about 6 percent for liraglutide 3.0 mg daily over the same window. The gap is structural rather than dose-dependent: semaglutide's longer half-life produces steadier receptor occupancy, which is the variable most strongly correlated with weight-loss magnitude in this drug class. Liraglutide is the older, more established option; semaglutide is the more aggressive one on the loss curve.

Mechanism, cadence, and what shows up in a log

Titration on liraglutide is daily and incremental — 0.6, 1.2, 1.8, 2.4, 3.0 mg added in weekly steps. Semaglutide titrates through 0.25, 0.5, 1.0, 1.7, 2.4 mg in 4-week steps. The total ramp time is similar (about a month for both to reach a working dose, longer to top dose), but a daily versus weekly cadence changes the shape of the early-weeks log dramatically — daily users see and score side effects 7x as often, which can make liraglutide read as harsher in a log even when the absolute side-effect rate is comparable.

For tracking purposes the two molecules occupy very different ergonomic categories. A weekly shot is one calendar event; a daily shot is a ritual that needs to land in roughly the same window every day. The calculator pages linked below handle the unit math for either, and the dose-per-vial column on the table above shows how a single vial stretches across the two cadences at the example vial size.

Semaglutide vs Liraglutide: the numbers, side by side

Start with what actually goes into a syringe. The example Semaglutide vial on this site reconstitutes 5 mg in 2 mL of bacteriostatic water — about 2.50 mg per mL, which yields roughly 20 doses at the 0.25 mg example and lasts about 20.0 weeks at 1 dose per week. The example Liraglutide vial reconstitutes 6 mg in 3 mL (2.00 mg/mL), which yields about 5 doses at 1.2 mg and stretches roughly 0.7 weeks at 7 doses per week. Those numbers are the starting point most people forget to write down, and they decide everything downstream — refill timing, unit count on the syringe barrel, and whether a 30-mL bac-water bottle stretches across one vial or two.

Category context matters too. Both Semaglutide and Liraglutide sit in the GLP-1 bucket, so the head-to-head questions readers bring here are usually about cadence, titration step size, and which of the two molecules logs more cleanly inside a longer protocol rather than a from-scratch category choice. Cadence helps frame the rest: Semaglutide is logged about 1× per week in the example schedule, Liraglutide about 7×.

The single most-asked-about mistake on each page is worth surfacing here, because they rarely overlap. On the Semaglutide side: Switching to a new vial of the same peptide and reusing the old unit count without re-running the calculation against the new vial's diluent volume. On the Liraglutide side: Failing to titrate the dose up slowly. Both are the kind of thing a tracked log catches early and an untracked routine catches late.

Top Semaglutide question
How is semaglutide reconstituted?

By adding a measured volume of bacteriostatic water to the lyophilized vial through the rubber stopper, then swirling — not shaking — until the powder fully dissolves into a clear solution. The exact diluent volume is up to the user; common choices for a 5 mg vial are 1, 2, or 3 mL.

Top Liraglutide question
What's the difference between Saxenda and Victoza?

Saxenda and Victoza contain the same active ingredient, Liraglutide. However, they are used for different purposes and at different maximum doses. Saxenda is generally used for weight management and has a higher target dose (3.0 mg), while Victoza is primarily used for blood sugar management in type 2 diabetes and has a lower target dose (1.8 mg).

The calculator pages linked below let you swap your own vial size, diluent volume, and dose into the same math — these example numbers exist so the comparison renders with concrete figures instead of placeholders.

Frequently asked questions about Semaglutide vs Liraglutide

How is semaglutide reconstituted?
By adding a measured volume of bacteriostatic water to the lyophilized vial through the rubber stopper, then swirling — not shaking — until the powder fully dissolves into a clear solution. The exact diluent volume is up to the user; common choices for a 5 mg vial are 1, 2, or 3 mL.
How many units of semaglutide are in 0.25 mg?
It depends on the concentration of your vial. On a 5 mg vial reconstituted with 2 mL of bacteriostatic water, 0.25 mg is exactly 10 units on a U-100 insulin syringe. On a 5 mg vial reconstituted with 1 mL, the same dose is 5 units.
Why is semaglutide dosed weekly?
Because its half-life is approximately one week, which keeps blood plasma levels stable on a once-weekly injection schedule. That cadence is part of why semaglutide became attractive relative to earlier GLP-1 peptides that required daily dosing.
What's the difference between Saxenda and Victoza?
Saxenda and Victoza contain the same active ingredient, Liraglutide. However, they are used for different purposes and at different maximum doses. Saxenda is generally used for weight management and has a higher target dose (3.0 mg), while Victoza is primarily used for blood sugar management in type 2 diabetes and has a lower target dose (1.8 mg).
Why is Liraglutide injected daily instead of weekly?
Liraglutide was designed to last for about 13 hours in the body. A once-daily injection ensures that there is a stable and effective level of the peptide in your system throughout the day. Other GLP-1 agonists, like Semaglutide, were later engineered to last even longer, allowing for a once-weekly dosing schedule.
What are the commonly reported side effects?
The most frequently reported side effect of Liraglutide is nausea, especially when starting or increasing the dose. Other common side effects can include diarrhea, constipation, headache, or fatigue. These often decrease over time as the body adjusts to the peptide.

Related on Peptide Pilot

Log Semaglutide and Liraglutide side by side in the app

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