What the studies show
Intensive treatment added about 2.9 kg over ten years in UKPDS — the reason insulin is the wrong tool for anyone seeking to lose weight and one reason the GLP-1 drugs exist.
Several well-run randomised trials in people, pointing the same way. You can plan around this. It still says nothing about whether the effect is worth the side effects for you.
- 1UK Prospective Diabetes Study (UKPDS) Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33).Lancet, 1998;352:837–8533,867 newly diagnosed patients, 10 years.
In context
Insulin is the 51-amino-acid hormone that lets cells take up glucose; recombinant human insulin and its engineered analogues are the treatment for type 1 diabetes and a mainstay of type 2. The landmark trials are settled: intensive insulin therapy cut new diabetic eye disease by 76% over six and a half years in the DCCT, and intensive glucose control reduced microvascular complications by a quarter over ten years in UKPDS. The cost, quantified in the same trials, is severe hypoglycaemia. It is on this site as the reference peptide, and because it is on WADA's list.
Insulin is approved (rx). Legal status differs by country — see the regulation section or the jurisdiction pages.
Questions
Is Insulin proven to cause weight gain?
What studies are behind the grade?
Is Insulin approved for this?
Other outcomes for Insulin
- ADiabetic retinopathy (type 1, intensive vs conventional)1 large RCT (DCCT, n=1,441, 6.5 yr)
- AMicrovascular complications (type 2)1 large RCT (UKPDS 33, n=3,867, 10 yr)
- ASevere hypoglycaemiaadverseBoth landmark RCTs
Written and maintained by LYO Research — how pages are written and checked. Reviewed 7 October 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →