Discovery of Insulin 50p (2021)
The Discovery of Insulin 50p of 2021 marks a century since insulin was discovered in 1921, with a crystal-structure design and the hormone's molecular formula. It was the fifth Innovation in Science 50p and was sold only to collectors. It is one of the nine Innovation in Science coins and one of the 172 50p designs struck since 1969.
Discovery of Insulin 50p value
- Uncirculated
- typical £15, range £13 to £16
Worked out from 7 published prices (4 dealer prices, 2 sold-price reports and 1 price guide), each condition from its own prices, checked in September 2026.
The Discovery of Insulin 50p was sold as a brilliant uncirculated collector coin, so wear from change does not come into its price; packaging and surface quality do. A coin still in its Royal Mint pack sells for more than one taken out and kept loose or moved into a capsule or third-party card. Spotting, scratches and handling marks on the crystal pattern reduce the price. Precious metal versions, in silver proof, silver piedfort and gold proof, were limited editions sold at their own prices.
Discovery of Insulin 50p mintage and rarity
The Discovery of Insulin 50p was not issued for circulation, so it has no rarity rank.
How to spot a Discovery of Insulin 50p
An interpretation of insulin crystals fills the reverse, with the word insulin in lower-case letters. Look for the chemical formula beginning with C and running through H, N, O and S, the clearest sign you have the insulin coin rather than another science design. The designer's initials IDLT are also on the reverse. Queen Elizabeth II and the date 2021 are on the obverse. It was a collector issue only, never released into general circulation.
Discovery of Insulin 50p design
Before insulin was found, diabetes had no cure and almost no treatment that worked. In 1921 Frederick Banting, Charles Best and John Macleod, with James Collip, discovered the hormone, which changed the treatment of diabetes and the prospects of the people living with it. The Royal Mint marked the 100th anniversary with the fifth coin of its Innovation in Science series, the first time the discovery had appeared on a UK coin. Iris De La Torre designed the reverse as an artistic interpretation of the structure of insulin crystals, spreading the pattern across the whole face of the coin. Worked into it are the word insulin, set in lower case, and the hormone's molecular formula, a string of chemical symbols for carbon, hydrogen, nitrogen, oxygen and sulphur. Her initials IDLT are on the reverse. Like the other science coins of 2021, it has Jody Clark's fifth portrait of Queen Elizabeth II on the obverse.
It was one of the three coins in the Innovation in Science set issued in 2021.
Discovery of Insulin 50p specifications
- Denomination
- 50p
- Year
- 2021
- Type
- Commemorative
- Issue
- Not issued for circulation
- Series
- Innovation in Science
- Occasion
- Centenary of the discovery of insulin in 1921 by Banting, Best and Macleod
- Designer
- Iris De La Torre
- Composition
- Cupro-nickel
- Weight
- 8 g
- Diameter
- 27.3 mm
- Shape
- Seven-sided
- Edge
- Plain
- Obverse
- Elizabeth II, fifth portrait by Jody Clark
Discovery of Insulin 50p questions
Is the Insulin 50p in circulation?
No. The 2021 Discovery of Insulin 50p went only to collectors, in brilliant uncirculated packs and precious metal proof editions.
What is the formula on the Insulin 50p?
It is the molecular formula of insulin, which lists the carbon, hydrogen, nitrogen, oxygen and sulphur atoms that make up the hormone.
Who designed the Insulin 50p?
Iris De La Torre. Her initials, IDLT, form part of the reverse design.