A short history of diabetes research
From early clinical descriptions to insulin, molecular understanding, monitoring, immune modulation, and cell replacement.
By The Diabetes Guide editorial project · Updated 30 Sept 2026
On this page
Before insulin, severe diabetes could be fatal quite quickly. Insulin was made ready for use in 1921–1922, and tools have improved ever since.
Step 1: 1921–1922
The Toronto team’s work led to the first treatment of a patient with insulin in 1922.
For example: A lifeboat arriving after a long wait.
Step 2: Better tools
Purified insulin, meters, HbA1c, pumps, CGM and new medicines built step by step.
For example: From candle to lightbulb to smart lamp.
Step 3: Still unfinished
Devices manage sugar; cell therapy needs immune care. A cure is not guaranteed by history.
For example: A good start does not make the finish line closer than it is.
Remember: Each milestone solved one problem, not every problem.
The full story
Want more? Below is the detailed version with the real science words. It is fine to skip it.
The turning point
Before insulin treatment, severe insulin-deficient diabetes was generally fatal within a short period. The Toronto work in 1921 and treatment of Leonard Thompson in 1922 transformed that outlook. Banting, Best, Macleod and Collip contributed through experimental work, leadership and purification; discovery was a collective scientific process. 1
Ancient descriptions
Physicians describe excessive urination and wasting, without modern disease classification.
19th century
Experimental research increasingly connects the pancreas to glucose regulation.
1921
The Toronto insulin experiments establish a transformative treatment direction.
1922
Human insulin treatment becomes a clinical reality.
Later 20th century
Purified and recombinant insulin, glucose meters, HbA1c measurement and pumps reshape management.
21st century
CGM and automated delivery connect sensing to treatment; incretin therapies broaden Type 2 options.
2025–2026
Cell-replacement evidence and expanded immune-modulation indications address disease mechanisms.
Progress does not erase the remaining work
Devices can improve regulation while autoimmunity persists. Cell therapy can restore secretion while immune suppression remains necessary. Historical milestones should be read as specific capabilities gained, not a narrative that makes a universal cure inevitable. 234
Trace the evidence
Sources and further reading
1.The discovery of insulin (opens in a new tab)
Nobel Prize educational archive · 2026 · Reference
Who was studied, limits and source check
Limitations: Historical educational account accessed in 2026; not a clinical evidence source.
Source checked 2026-09-30. See the original publication for full methods.
2.Diabetes Technology: Standards of Care 2026 (opens in a new tab)
American Diabetes Association · 2026 · Guideline
Who was studied, limits and source check
Limitations: Access, training, device labeling, and safe-use capacity affect applicability.
Source checked 2026-09-30. See the original publication for full methods.
3.FDA accelerated approval: teplizumab in selected recently diagnosed pediatric Stage 3 T1D (opens in a new tab)
US Food and Drug Administration · 2026 · Regulatory
Who was studied, limits and source check
Population: Children aged 8–17 recently diagnosed with Stage 3 T1D
Sample: PROTECT: 328 participants
Limitations: June 12 accelerated approval based on C-peptide preservation, a surrogate. Confirmatory clinical benefit and label conditions matter.
Source checked 2026-09-30. See the original publication for full methods.
4.Stem Cell–Derived, Fully Differentiated Islets for Type 1 Diabetes (opens in a new tab)
Reichman et al.; New England Journal of Medicine · 2025 · Early human study
Who was studied, limits and source check
Population: Selected adults with T1D, severe hypoglycemia and impaired awareness
Sample: 14 with ≥12-month follow-up; 12 at full dose
Limitations: Small, uncontrolled interim analysis; required immunosuppression; serious adverse events and deaths occurred. Not a routine cure.
Source checked 2026-09-30. See the original publication for full methods.
Source checking is an editorial literature check, not independent medical review. This page is for learning. It cannot diagnose you or make a treatment plan. Evidence labels describe the cited claims, not the whole topic.
What does “Established” mean?
Doctors and scientists agree. This is well known. Like “the sun rises in the east”.
Keep reading
The body
The one-page mental model
Diabetes means there is too much sugar in the blood for too long, because the body does not have enough insulin or cannot use it well.
Type 1
Type 1 diabetes: the complete journey
Type 1 diabetes is usually an autoimmune condition. The body’s defence system harms the beta cells, so less and less insulin is made.
Type 2
Type 2 diabetes: how the system changes
Type 2 diabetes happens when the body’s need for insulin grows and the pancreas cannot keep up, so sugar slowly rises.