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GLP-1 medicines (UK)
UK GLP-1 Centre — weight-loss and diabetes medicines
Plain-English UK guidance on the GLP-1 receptor agonist medicines — semaglutide (Wegovy / Ozempic), tirzepatide (Mounjaro), liraglutide (Saxenda / Victoza). Patient-pathway view: access routes, prescriber interactions, side-effect literacy, and counterfeit-pen safety. For the regulatory analysis, see the UK Law hub.
Brand guides
Wegovy UK guide
Semaglutide for weight management. FixDose pen, NICE TA875, lawful access, counterfeit identifiers.
Mounjaro UK guide
Tirzepatide KwikPen, NICE TA1026, Feb 2026 falsified-pen alert, lawful access.
Ozempic UK guide
Semaglutide for type 2 diabetes. Off-label weight-loss caveats and the supply pressure picture.
Saxenda UK guide
Daily-injection liraglutide for weight management. Where it still fits post-Wegovy/Mounjaro.
Rybelsus UK guide
Oral semaglutide for type 2 diabetes. Why food timing is critical and why there's no oral Wegovy.
Active ingredients
Semaglutide (active ingredient)
Pharmacology, UK access pathways, the Wegovy / Ozempic / Rybelsus split.
Tirzepatide (active ingredient)
Dual GLP-1 / GIP mechanism. Trial data, side-effect picture, UK pathway.
Liraglutide (active ingredient)
Daily-injection GLP-1; Saxenda for weight, Victoza for diabetes.
Comparisons
Side effects
Mounjaro side effects (UK)
Common, less common, serious, and red flags. UK patient reference.
GLP-1 nausea
Why it happens, the dose-step curve, what helps in practice.
GLP-1 constipation
Under-reported. The fluid / fibre / laxative escalation ladder and bowel-obstruction red flags.
GLP-1 gallbladder risk
Trial signal, mechanism, symptoms to recognise, when to seek urgent care.
GLP-1 pancreatitis
Red-flag symptoms, what to do, why a history of pancreatitis matters.
GLP-1 pregnancy & fertility
Contraindicated in pregnancy. Washout, contraception, and restored-fertility risk.
Side-effect literacy
Overview across the GLP-1 class. Yellow Card reporting.
Access and supply
NHS access pathway
Tier 3 weight-management services, NICE criteria, GP referral.
Private clinics — what good looks like
Registration checks for evaluating a private prescriber.
NHS vs private GLP-1
Cost vs eligibility vs speed. The honest trade-off.
Talking to your GP
Questions for before, during, and after a GLP-1 prescription.
GLP-1 shortages & supply
Why GLP-1s run short, what to do if yours is unavailable, why grey market is the wrong answer.
Counterfeits and reporting
Fake Mounjaro pens
Feb 2026 MHRA alert on falsified 15 mg KwikPens. Identifiers and reporting.
Fake Ozempic pens
Counterfeit Ozempic patterns and what to check.
Fake Wegovy pens
FixDose pen format, counterfeit patterns, what to check before injecting.
Fake Saxenda pens
Daily multi-dose pen format. Lower counterfeit volume but still on MHRA's radar.
Fake retatrutide pens
No licensed reference product exists. Every retatrutide vial sold outside a trial is by definition unverified.
Check a UK online pharmacy (GLP-1)
The six-check protocol before paying for a GLP-1 prescription.
What to do if your pen looks wrong
The immediate action ladder. Stop, photograph, report — don't inject.
Bought from social media — what to do
Action ladder for the Instagram / TikTok / Telegram supply path. Chargeback, Action Fraud, platform reporting.
Practical use
Investigational (not licensed)
Retatrutide UK status
Investigational triple-agonist (GLP-1 / GIP / glucagon). Lawful access via clinical trial only.
Cagrilintide UK status
Long-acting amylin analogue. CagriSema combination with semaglutide. Investigational.
Amycretin UK status
Single-molecule GLP-1 / amylin co-agonist. Early-stage investigational.
Related
- Semaglutide and UK law — regulatory analysis.
- Tirzepatide and UK law — regulatory analysis.
- Fake weight-loss pens and UK law — MHRA enforcement.
- How to check a UK pharmacy — GPhC / PSNI register lookup.
- GLP-1 medicines FAQ — 15 common questions answered.