If you’re deciding between Mounjaro and Saxenda, the biggest real-world difference is simple:

Mounjaro (tirzepatide): once weekly injection
Saxenda (liraglutide): once daily injection

Everything else dose build-up, tolerance, and eligibility flows from that.

Table of Contents

Fast answer: weekly vs daily what it changes

Weekly (Mounjaro) often suits people who…

want fewer injections and fewer “daily reminders”
prefer a weekly routine (same day each week)
find consistency easier with one scheduled injection

Daily (Saxenda) often suits people who…

prefer a daily habit (like brushing teeth / daily meds)
feel more comfortable with gradual daily adjustment
don’t mind injecting daily at roughly the same time

Neither is “automatically better.” The best option is the one you can follow safely and consistently with clinician guidance.

1) What each medicine is (active ingredient)

Mounjaro = tirzepatide

Mounjaro contains tirzepatide and is used for weight loss and weight maintenance in adults by regulating appetite (fullness, less hunger, fewer cravings).
If you want the mechanism explained clearly, read How Mounjaro Works for Weight Loss.

Saxenda = liraglutide

Saxenda contains liraglutide, described in the UK leaflet as a weight loss medicine similar to the natural hormone GLP-1.

2) Dosing build-up: how you step up to a maintenance dose

Mounjaro dose build-up (weekly)

The Mounjaro KwikPen leaflet states:

start at 2.5 mg once a week for 4 weeks, then
increase to 5 mg once weekly, and
if needed, increase by 2.5 mg steps (7.5, 10, 12.5, 15) staying at each dose at least 4 weeks before moving up.

Saxenda dose build-up (daily)

The Saxenda leaflet states adults typically follow:

Week 1: 0.6 mg once daily
Week 2: 1.2 mg once daily
Week 3: 1.8 mg once daily
Week 4: 2.4 mg once daily
Week 5 onwards: 3.0 mg once daily

Why titration exists (both medicines): it’s mainly to improve tolerance, especially for stomach-related side effects early on.

3) The “continue or stop” rule (Saxenda has a clear one)

Saxenda’s UK leaflet is very direct: adults should only continue if they have lost at least 5% of their initial body weight after 12 weeks on the 3.0 mg/day dose.

This matters because it sets expectations:

Saxenda is often treated as a “trial with a checkpoint” (continue only if response is meaningful by that point).

4) Eligibility & NHS access (the UK reality)

Even if you’re choosing privately, UK guidance shapes how clinicians think.

NICE TA664 recommends liraglutide (Saxenda) for managing overweight/obesity only for a narrow subgroup, including:

BMI threshold (≥35, or ≥32.5 in certain minority ethnic groups),
non-diabetic hyperglycaemia,
high cardiovascular risk, and
prescribing through a specialist multidisciplinary Tier 3 weight management service.

So on the NHS, Saxenda access is typically not “anyone with a BMI over X” it’s more restricted and specialist-led.

5) Side effects (high level) and what “weekly vs daily” can feel like

Both leaflets list GI side effects and dehydration risk as things to watch especially early.

What changes with frequency:

With daily dosing (Saxenda), some people feel they can “nudge” tolerance week-by-week because it’s a daily habit with weekly titration.
With weekly dosing (Mounjaro), side effects can cluster around the injection day in some people, and dose steps happen over multi-week blocks.

Practical habits that help either way:

smaller meals early on
steady hydration (important if nausea/diarrhoea happens)

Comparison table: differences that matter

Difference	Mounjaro	Saxenda	Why it matters
Injection frequency	Once weekly	Once daily	Adherence style: weekly routine vs daily habit
Active ingredient	Tirzepatide	Liraglutide (GLP-1-like)	Different medicine class
Dose build-up	2.5 mg weekly → 5 mg weekly; +2.5 mg steps as needed	0.6 mg daily → 3.0 mg daily by week 5	Different escalation tempo
Response checkpoint	Not stated like Saxenda’s in leaflet excerpt	Continue only if ≥5% weight loss after 12 weeks on 3.0 mg/day	“Trial period” logic is clearer for Saxenda
NHS recommendation	(separate NICE appraisal)	NICE TA664 is narrow + Tier 3 specialist services	Access can be more restricted on NHS

“Which one should I choose?” (safe, non-prescriptive)

Use this as a clinician discussion guide:

If you struggle with daily routines, a weekly injection may be easier to stick to.
If you prefer a daily habit and like the idea of a clear “12-week checkpoint,” Saxenda’s continuation rule may appeal.
If NHS pathway matters: Saxenda’s NICE recommendation is specialist Tier 3 and narrow.

If you’re going ahead with Mounjaro on MedCare, start here:
Mounjaro weight loss injection pen.

FAQs

Is Saxenda really daily?

Yes. The Saxenda leaflet shows a once-daily dosing schedule, titrating up weekly to once daily from week 5 onwards.

Is Mounjaro really weekly?

Yes. The Mounjaro KwikPen leaflet specifies once-weekly dosing starting at 2.5 mg once weekly for 4 weeks, then increasing.

When should Saxenda be stopped if it isn’t working?

The UK leaflet says adults should only continue if they have lost at least 5% of initial body weight after 12 weeks on 3.0 mg/day.