Weight & Metabolic

A daily injectable prescription medicine that mimics a natural gut hormone to reduce appetite and aid weight loss, sold as Saxenda for weight management and Victoza for type 2 diabetes.

Grade A · Approved medicine or robust human trials.

A licensed prescription medicine that mimics a gut hormone to suppress appetite, improve blood sugar, and reliably produce weight loss.

Grade A · Approved medicine or robust human trials.

A prescription injection that mimics two gut hormones at once to reduce appetite, lower blood sugar and drive substantial weight loss.

Grade A · Approved medicine or robust human trials.

An investigational once-weekly injection combining semaglutide with cagrilintide (a synthetic amylin analogue) to achieve greater weight loss than either component alone.

Grade B · Human trials exist but are incomplete.

Cagrilintide is an experimental once-weekly injection mimicking the body's fullness hormone amylin to reduce appetite and body weight. The trial results are impressive, but it is not yet an approved medicine.

Grade B · Human trials exist but are incomplete.

An injectable obesity drug, approved in China but not the UK, that mimics two gut hormones to suppress appetite and increase energy expenditure.

Grade B · Human trials exist but are incomplete.

An experimental once-weekly injectable that hits three metabolic hormone receptors at once and has produced the largest trial weight-loss results seen so far. It is not yet an approved medicine.

Grade B · Human trials exist but are incomplete.

An experimental once-weekly weight-loss and liver-disease injection that works on two metabolic hormone targets at once. Strong trial results so far, but not yet approved anywhere.

Grade B · Human trials exist but are incomplete.

A failed Parkinson's/Alzheimer's brain drug, repurposed as a potent appetite suppressant — it produced striking weight loss in a Phase II trial but has never made it through to a licensed obesity medicine.

Grade B · Human trials exist but are incomplete.

A synthetic fragment of growth hormone designed to burn fat without the hormone's side effects, but human trials showed it failed to produce meaningful weight loss and development was abandoned.

Grade C · Some human data, far from settled.

A lab-made small molecule that blocks an enzyme (NNMT) to nudge fat tissue toward burning rather than storing energy — convincing in obese mice, completely untested in people.

Grade D · No meaningful human evidence yet.

The tail-end snippet of growth hormone that's marketed as a "fat-burning" peptide, based mostly on mouse studies - the human version of this idea (AOD-9604) was tested properly and didn't work.

Grade D · No meaningful human evidence yet.

A clinic-mixed injection of everyday nutrients (methionine, inositol, choline, often with carnitine and B-vitamins) marketed as a fat-burner, with no controlled human evidence that the shot itself burns fat.

Grade D · No meaningful human evidence yet.