UK Weight Loss Injection Guide
Weight Loss Injections Explained
The complete guide to Semaglutide, Tirzepatide, Retatrutide and Melanotan 2 — how they work, what results to expect, and why thousands of UK customers choose Slim Shots.
The Weight Loss Injection Revolution
Weight loss injections have transformed the way people across the UK approach fat loss. Semaglutide and Tirzepatide — the active ingredients behind Ozempic®, Wegovy®, and Mounjaro® — have delivered results that diet and exercise alone rarely achieve. Now, the next generation is here: Retatrutide, a triple-agonist injection that targets three receptor pathways simultaneously for even more powerful fat loss.
At Slim Shots, we supply Semaglutide, Tirzepatide, Retatrutide and Melanotan 2 tanning injections — all lab-verified, pharmaceutical-grade, and delivered discreetly across the UK. This page gives you everything you need to know about how these injections work and what to expect.
Important: The information on this page is for educational purposes. Always consult a qualified healthcare professional before starting any injectable weight loss programme.
How Do Weight Loss Injections Work?
Semaglutide is a GLP-1 receptor agonist — it mimics the natural GLP-1 hormone that regulates appetite, slows gastric emptying, and controls insulin secretion. The result? You feel fuller for longer, eat less, and your body burns stored fat more efficiently.
Tirzepatide goes further as a dual GLP-1/GIP agonist, targeting two receptor pathways at once. This dual action produces superior weight loss results compared to single-agonist options — which is why it's become one of the most sought-after weight loss injections in the UK.
Retatrutide is the most advanced option available — a triple agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. Early data shows it may deliver the most significant weight loss results of any injectable currently available.
Our Weight Loss Injections in Detail
Semaglutide
GLP-1 Receptor Agonist · Same active ingredient as Ozempic® & Wegovy®
Semaglutide is the most widely recognised weight loss injection in the UK. As the active ingredient in Ozempic® and Wegovy®, it has been clinically studied in large-scale trials showing significant body weight reductions in participants over 68 weeks. It works by suppressing appetite, reducing caloric intake, and improving metabolic function.
Typically administered as a once-weekly subcutaneous injection, Semaglutide is dosed gradually — starting low and increasing over several weeks to minimise side effects and maximise results.
Tirzepatide
Dual GLP-1/GIP Agonist · Same active ingredient as Mounjaro®
Tirzepatide is widely regarded as the most effective weight loss injection currently available in mainstream use. As the active ingredient in Mounjaro®, it targets both GLP-1 and GIP receptors — producing superior fat loss results compared to Semaglutide alone. Clinical trials have reported average weight reductions significantly higher than those seen with single-agonist options.
Like Semaglutide, Tirzepatide is administered as a once-weekly subcutaneous injection with a gradual dose escalation protocol. It's become the go-to choice for those who want maximum results from their weight loss injection.
Retatrutide
Triple GLP-1/GIP/Glucagon Agonist · The Future of Weight Loss Injections
Retatrutide is the most advanced weight loss injection available today. Unlike Semaglutide (single agonist) or Tirzepatide (dual agonist), Retatrutide simultaneously activates three receptor pathways: GLP-1, GIP, and glucagon. This triple-action mechanism produces the most powerful appetite suppression and fat-burning effect of any injectable currently on the market.
Phase 2 clinical data has shown remarkable weight loss results with Retatrutide, with participants achieving reductions that surpass those seen with both Semaglutide and Tirzepatide. It represents the cutting edge of injectable weight loss science.
Melanotan 2 (MT2)
Tanning Injection · UK's Most Popular Tanning Peptide
Melanotan 2 (MT2) is the UK's most popular tanning injection. It works by stimulating the body's melanocortin receptors, triggering increased melanin production — the pigment responsible for skin colour. The result is a deep, natural-looking tan that develops with minimal sun exposure.
MT2 is typically administered as a small subcutaneous injection, with users reporting visible tanning results within days. It's widely used across the UK as an alternative to sunbeds and prolonged UV exposure.
Comparing Weight Loss Injections
How do Semaglutide, Tirzepatide and Retatrutide stack up against each other — and against branded alternatives?
| Injection | Mechanism | Branded Equivalent | Slim Shots Price |
|---|---|---|---|
| Semaglutide | GLP-1 Agonist | Ozempic® / Wegovy® | Fraction of branded cost |
| Tirzepatide | Dual GLP-1/GIP Agonist | Mounjaro® | Fraction of branded cost |
| Retatrutide | Triple GLP-1/GIP/Glucagon | Next-gen (no branded equiv. yet) | Available now at Slim Shots |
| Melanotan 2 | Melanocortin Agonist | UK's #1 tanning injection | Competitive UK pricing |
What Healthcare Professionals Say
Quotes from registered healthcare professionals, sourced from publicly available educational resources.
Hywel McGlinchy
Author on Simple Online Pharmacy
"One of the main things people notice with GLP-1 medicines is that their appetite changes. That effect is central to how these treatments work when used for weight management."
Dr Zoe Miller
Author on Asda Online Doctor
"These medicines were first developed for diabetes management, and only later did weight-related benefits become a major focus of research and clinical use."
Stuart Gale
Author on Oxford Online Pharmacy
"Changes in appetite and eating behaviour are often reported quite early in treatment, even before the full effect on weight is seen."
Why Buy Your Weight Loss Injections from Slim Shots?
Lab-Verified Purity
Every batch of Semaglutide, Tirzepatide, Retatrutide and MT2 is independently tested at accredited UK laboratories.
Fraction of Branded Prices
Same active ingredients as Ozempic®, Wegovy® and Mounjaro® — at a fraction of the cost.
Fast, Discreet UK Delivery
Temperature-controlled, plain packaging with full tracking — delivered fast across the UK.
Trusted Since 2019
Thousands of satisfied UK customers. Slim Shots has been the go-to weight loss injection supplier since 2019.
Expert Support 7 Days a Week
Our team is available via WhatsApp and email to answer your questions about dosing, delivery, and product selection.
Full Certificates of Analysis
Purity reports and batch testing documentation available for every product we supply.
Ready to Buy Weight Loss Injections in the UK?
Shop Semaglutide, Tirzepatide, Retatrutide and Melanotan 2 — lab-verified, discreetly delivered across the UK.
Same active ingredients as Ozempic® · Wegovy® · Mounjaro® · Fast UK delivery · Trusted since 2019