I Tried to Figure Out What Weight Loss Injections Actually Cost in the UK. Here's My Notes.

 

I want to be clear upfront about what this post is and isn't.

It is not a review. I'm not here to tell you which weight loss injection to choose, or which pharmacy to use, or whether any of this is right for you. Those are conversations for a doctor.

What this is, is a record of what I found when I spent several hours trying to answer a genuinely simple question: how much do these treatments actually cost in the UK?

The answer, it turns out, is not simple at all. And the reasons why it's not simple are worth writing down because if you've tried to research this yourself, you've probably hit the same walls.

The Starting Point: Three Treatments, Lots of Prices

There are three main injectable weight loss treatments available privately in the UK right now:

Mounjaro (tirzepatide — weekly injection) Wegovy (semaglutide — weekly injection) Saxenda (liraglutide — daily injection)

All three are prescription-only. All three require a proper clinical assessment from a licensed prescriber before you can get them. None of them can be legally purchased without a prescription, regardless of what some websites might imply.

I started by looking up each one on a handful of pharmacy sites. Immediately, the numbers didn't make sense.

Mounjaro: £130 on one site, £200 on another. Same dose. Same drug. Different pharmacy.

Wegovy: £140 on one, £175 on another. Again, same dose.

I spent about 20 minutes confused before I realised the issue wasn't the pharmacies behaving strangely — it was that I didn't understand how the pricing structure worked. Once I figured that out, everything clicked into place.

The Bit That Changes Everything: Titration

GLP-1 medications don't work like a standard prescription where you're on one dose indefinitely from the start. They use a titration schedule you begin at the lowest possible dose and increase gradually over several months until you reach a maintenance dose that's right for you.

The reason is tolerability. Starting high causes nausea and other side effects that most people can't manage. So the protocol is: start low, go slow.

Here's the thing about titration and pricing: the price goes up at every step.

Mounjaro what you pay at each stage:

Dose	Monthly Cost
2.5 mg (start here)	£130–£180
5 mg	£155–£200
7.5 mg	£200–£270
10 mg	£220–£305
12.5 mg	£245–£315
15 mg (top dose)	£260–£340

Wegovy same deal:

Dose	Monthly Cost
0.25 mg (start here)	£130–£170
0.5 mg	£145–£185
1 mg	£175–£220
1.7 mg	£215–£270
2.4 mg (maintenance)	£240–£295

Saxenda is a daily injection, so it's priced differently — roughly £150–£290/month across the titration range.

So when a pharmacy says "from £130/month" — that's the first four weeks. If you're still on treatment six months later, you could easily be paying £260–£340 a month for Mounjaro, or £240–£295 for Wegovy.

That's roughly double the advertised number. Not because the pharmacy changed its prices. Just because of how the treatment works.

The Fees I Kept Finding Buried Somewhere

Once I understood the titration thing, I went back to comparing pharmacies more carefully. And I started noticing something: the pen prices weren't the whole story.

Different providers handle their fees differently. Some bundle everything in — the consultation, the delivery, the monitoring — and charge one all-in price. Others strip all of that out and charge separately.

So I started keeping a little mental list of what was getting added:

• Consultation fee — could be £0 (bundled) or £20–£50 (charged separately, sometimes per renewal too)
• Delivery — Mounjaro and Wegovy need cold chain delivery because they have to be refrigerated. Some providers do this free. Others charge up to £15 per order.
• Programme or monitoring fee — some providers wrap this into a monthly subscription charge on top of the medication

Worst case scenario: I'm looking at £130 pen price + £50 consultation + £15 delivery = £195 actual monthly cost. From a pharmacy advertising "Mounjaro from £130."

Best case: I find a provider at £175 for everything included. Which is actually cheaper.

This is why comparing just the listed pen price across pharmacies doesn't work.

What a Year Actually Costs: The Maths I Did

Since I was going down this rabbit hole anyway, I worked out some realistic annual estimates.

If I were on Mounjaro and stabilised at 7.5 mg:

• Months 1–3 (titration): £130 + £155 + £200 = £485 (low estimate)
• Months 4–12 at 7.5 mg: £200 × 9 = £1,800 (low estimate)
• Year 1 total: roughly £2,285–£3,080 depending on provider

If I went all the way to Mounjaro 15 mg:

• Year 1 total: roughly £2,770–£3,650

Wegovy to full 2.4 mg maintenance:

• Year 1 total: roughly £2,585–£3,205

These are medication only — add fees on top if they're charged separately.

None of these numbers are alarming or surprising once you know about the titration structure. They're just not the numbers that get advertised.

What I Looked for in a Pharmacy

After all this, here's the checklist I ended up with before considering any provider:

✅ GPhC registered? Check the number at pharmacyregulation.org — this is non-negotiable. Any pharmacy dispensing prescription medication in the UK without GPhC registration is operating illegally.

✅ MHRA internet pharmacy logo on the homepage? And is it clickable/linked? A static image of the logo is meaningless. It needs to link to the MHRA registry where you can verify it.

✅ Named prescriber with GMC number? The person signing the prescription should be identifiable. You can verify GMC numbers at gmcuk.org.

✅ All fees shown before I reach payment? If I have to go all the way to checkout to find out what I'm really being charged, that's a no from me.

✅ Real Trustpilot reviews? Not just quotes on the pharmacy's own website. Trustpilot ratings that anyone can read, go verify, and see the negative ones too.

Where I Found the Most Useful Comparison Data

After going through all of this manually, I found a platform that does most of this work aggregated in one place — Healthwise360's weight loss treatment price comparison.

It covers Mounjaro, Wegovy, and Saxenda across every dose step, from 60+ GPhC-registered pharmacies, with no referral relationships with any of them. The interactive comparison tool puts all three treatments side by side so you can actually compare like for like.

There's also a cheapest options UK page if you specifically want to identify the lowest verified costs at the moment, and individual guides for Mounjaro, Wegovy, and Saxenda if you want to understand what you'd actually be taking before thinking about cost.

A Few Things I Want to Be Clear About

I'm not a doctor. Nothing in this post is medical advice. These are prescription-only medicines and a proper clinical consultation is a legal requirement — not optional.

I'm not affiliated with any pharmacy. I don't benefit financially from you clicking any link in this post. The Healthwise360 links are there because it was genuinely the most useful resource I found.

These prices change. Everything here is approximate. Always verify directly with a GPhC-registered pharmacy before ordering anything.

What I hope this post does is save you the three hours I spent getting confused before understanding how the pricing structure works. Because once you understand the titration model, the fee bundling, and the real annual costs — the comparison process makes a lot more sense.