Research pipeline · Educational
Weight loss research pipeline
Several compounds in late-stage trials have reported weight reductions above anything currently licensed, retatrutide at 28.7% over 68 weeks, CagriSema at 22.7%. None of them is approved by the MHRA, EMA or FDA, and none can lawfully be prescribed, sold or supplied for human use. This section covers what the trials actually showed and where each compound sits in the approval process.
Why we do not sell these
“Research use only” is not a legal exemption. Under the Human Medicines Regulations 2012, supplying a molecule for human medicinal use without a marketing authorisation is unlawful, and attaching a research disclaimer does not change that where the marketing around it points to personal use. The MHRA has enforced against vendors on exactly that basis.
Beyond legality: vials bought this way have unverified identity, purity and dose, no pharmacovigilance behind them, and no clinician monitoring the person using them. For compounds that affect glucose handling and heart rate, that is the risk, and it is why this section is educational rather than a catalogue.
That applies to every compound on this page. Searching "buy retatrutide" returns vendors, and the volume of them is not evidence that it is available — retatrutide has no marketing authorisation from any regulator, so there is no lawful supply for a vendor to be part of. What is being sold is a powder of unverified identity with a disclaimer attached.
Compounds in development
- Phase 3 trials
Retatrutide
Eli Lilly · GLP-1 / GIP / Glucagon
28.7%Phase 3 · 68 weeksRetatrutide is an investigational triple hormone receptor agonist being developed by Eli Lilly for obesity. It acts on three receptors, GLP-1, GIP and glucagon, where Mounjaro acts on two and Wegovy on one.
Read the evidence - Submitted to regulators
CagriSema
Novo Nordisk · GLP-1 / Amylin
22.7%REDEFINE 1 · 68 weeksCagriSema is an investigational combination of semaglutide, the molecule in Wegovy, with cagrilintide, an amylin analogue. In the REDEFINE 1 trial it produced a mean weight reduction of 22.7% at 68 weeks, outperforming semaglutide alone.
Read the evidence - Phase 3 trials
Survodutide
Boehringer Ingelheim · GLP-1 / Glucagon
14.9%Phase 3 · 49 weeksSurvodutide is an investigational dual GLP-1 and glucagon receptor agonist from Boehringer Ingelheim, and the first in that class to publish Phase 3 results. It produced a mean weight reduction of 14.9% over 49 weeks.
Read the evidence - Phase 3 trials
Orforglipron
Eli Lilly · GLP-1
OralPhase 3 programme · ongoingOrforglipron is an investigational once-daily tablet from Eli Lilly. Unlike every licensed weight-management treatment, it is a small molecule rather than a peptide, which is what allows it to be taken orally without the absorption constraints peptides face.
Read the evidence
Common questions
When will the new weight loss drug 2026 coverage refers to actually be available?
No date can be given, and any provider offering one is guessing. Between a reported Phase 3 result and a medicine you can be prescribed sit a full regulatory submission, a review that runs many months, a national licence, and — separately — a decision about whether a health system will fund it. Each of those has failed for weight-management compounds before. The honest position is that a trial result tells you what a molecule did in a study, not when it will reach a pharmacy.
What are weight loss peptides, and are research peptides UK sellers offer the same thing?
Peptides are short chains of amino acids, and the licensed weight-management medicines are peptides — semaglutide and liraglutide both are. The difference is authorisation, not chemistry. What research peptides UK sites sell are unlicensed medicines: no marketing authorisation, no verified identity, purity or dose, no pharmacovigilance, and no clinician monitoring the person injecting them. That is the whole distinction, and it is the one that matters.
Can you buy research peptides for weight loss in the UK?
Not lawfully for human use. Compounds sold online as "research use only" peptides are unlicensed medicines under the Human Medicines Regulations 2012, and the disclaimer does not change that where the surrounding marketing points to personal use. The MHRA has taken enforcement action against such vendors, and seizures of trafficked weight-loss and peptide products have run into the tens of millions of pounds.
Why are unlicensed peptides risky beyond the legality?
Identity, purity and dose are unverified. There is no marketing authorisation behind the vial, no pharmacovigilance if something goes wrong, and no clinician monitoring you. With injectable compounds that affect glucose handling and heart rate, that combination is the problem, not the molecule in the abstract.
Which weight loss drug is coming next?
Retatrutide has reported the highest late-stage figure to date at 28.7% over 68 weeks, and CagriSema has reported 22.7% at 68 weeks with regulatory filing anticipated. Neither is approved. Reporting trial results is not the same as approval, and no launch date can be assumed until a regulator has reviewed a full submission.