Claimed effect · Insulin

Does Insulin help with diabetic retinopathy?

A
Grade A — established in humans1 large RCT (DCCT, n=1,441, 6.5 yr) · effect size: large
Short answerEstablished in humans. 1 large RCT (DCCT, n=1,441, 6.5 yr) point the same way: a large effect. Intensive insulin therapy — pump or three or more daily injections with frequent glucose monitoring — reduced new retinopathy by 76% and slowed existing retinopathy by 54%. Kidney and nerve complications fell too.

What the studies show

Intensive insulin therapy — pump or three or more daily injections with frequent glucose monitoring — reduced new retinopathy by 76% and slowed existing retinopathy by 54%. Kidney and nerve complications fell too.

“In the primary-prevention cohort, intensive therapy reduced the adjusted mean risk for the development of retinopathy by 76 percent (95 percent confidence interval, 62 to 85 percent), as compared with conventional therapy.”

Verbatim, from the abstractThe Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med, 1993;329:977–986

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.

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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 help with diabetic retinopathy?
Yes, as far as human trials can show it: 1 large RCT (DCCT, n=1,441, 6.5 yr). LYO grades this outcome A.
What studies are behind the grade?
Intensive insulin therapy — pump or three or more daily injections with frequent glucose monitoring — reduced new retinopathy by 76% and slowed existing retinopathy by 54%. Kidney and nerve complications fell too.
Is Insulin approved for this?
Insulin is an approved medicine (Approved (Rx)); whether this particular outcome is a licensed indication is stated on the compound page's regulation section.

Other outcomes for Insulin

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 →