What is it?
Sucralose is a man-made sweetener made from table sugar. During manufacture, three parts of the sugar molecule are swapped for chlorine atoms. The result is about 600 times sweeter than sugar. It adds almost no calories.
E-numbers / Sweeteners / E955
Sucralose
also: Splenda · Trichlorogalactosucrose
The sweetener in Splenda, made by swapping parts of a sugar molecule for chlorine. A 2025 trial found a month of it cut insulin sensitivity by a fifth.
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Water, Blackcurrant Juice From Concentrate (12%), Flavourings, Antioxidant: Ascorbic Acid; Colour: Anthocyanins; Acid:Malic Acid; Sweetener: Sucralose.
E955
Sucralose
Regular intake is linked to reduced insulin sensitivity and changes in gut bacteria in human trials.
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UK supermarket foods that declare E955: 1,493 of the 43,325 we checked (3.4%)
Counted by its code or its name in the ingredient list.
Only 1.2% of these labels print “E955”. Most use the name: look for “sucralose”.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
How common it is in UK food, by aisle
- Soft drinks and juices859 products33% of 2,627
- Yoghurt, milk and dairy129 products5.7% of 2,273
- Fruit, vegetables and salad104 products4% of 2,631
- Chocolate and sweets86 products4.2% of 2,045
What sucralose is, what it does and where you will see it
Why it’s worth knowing. Regular intake is linked to reduced insulin sensitivity and changes in gut bacteria in human trials. When heated in baking, sucralose can break down into chlorine-containing compounds whose safety at those amounts regulators have not confirmed.
What does it do?
It triggers sweet taste receptors on the tongue, and in the gut, without giving the body any glucose to use. In the gut it may act on taste receptors that affect how sugar is absorbed and which hormones are released after eating. That is the suggested route for the effects on insulin and gut bacteria seen in recent trials.
Where you will see it
Diet fizzy drinks, squash, flavoured waters, reduced-sugar yoghurts, protein bars and shakes, chewing gum, sweetener sachets and tablets, sugar-free jams, sauces and some lower-sugar baked goods. UK labels call it sucralose or E955.
What the science says
It reduced insulin sensitivity in healthy adults
A 2025 randomised trial gave healthy adults sucralose for 30 days. Their insulin sensitivity fell by about a fifth compared with a dummy, and their blood sugar and insulin were higher after a test meal. An earlier ten-week trial found similar signs. One suggested reason is that sucralose acts on sweet receptors in the gut and changes gut bacteria, but the full chain is not yet proven.
30 days of sucralose in healthy lean adults cut insulin sensitivity by 20.3% compared with a dummy, and raised blood sugar, insulin and GLP-1 after a test meal.
2025Randomised trial in peopleRomo-Romo et al., randomised placebo-controlled triple-blind trial, Clinical Nutrition ESPEN
Ten weeks of sucralose in healthy young adults was linked to changes in gut bacteria and altered blood sugar and insulin.
2022Randomised trial in peopleFrontiers in Nutrition / PMC8880058
It changes gut bacteria
Several human trials have found that regular sucralose makes the mix of gut bacteria less varied and shifts which species are there, along with the short-chain fatty acids they make. Researchers suggest this may feed low-level gut inflammation and changes in how the body handles sugar. The evidence is building, but what it means at normal UK intakes is uncertain.
Sucralose made gut bacteria less varied and changed short-chain fatty acids in healthy adults, compared with a dummy.
2025Randomised trial in peopleRomo-Romo et al., randomised placebo-controlled triple-blind trial, Clinical Nutrition ESPEN
In mice, sucralose changed gut bacteria and was linked to signs of liver inflammation.
2017Animal studyJournal of Toxicology and Environmental Health / PMC5522834
Heating it in baking
Heated to baking temperatures, sucralose can break down and form chlorine-containing compounds called chloropropanols, which are a known toxic concern. In 2026 European reviewers were asked to allow it in more baked goods. They could not confirm that was acceptable, because of how these compounds might form across the range of baking methods. This is the main open question for regulators.
Reviewers kept sucralose's current uses and daily limit, but could not conclude on extending it to cakes, biscuits and pastries, because of uncertainty over chlorinated compounds formed in baking.
2026Regulator reviewEFSA re-evaluation opinion, EFSA Journal
Where it stands with the regulators
Approved in the UK and the EU
Daily limit. 15mg per kg of body weight a day, kept unchanged by European reviewers in 2026. The UK FSA has not separately updated it.
- Legal basis
- On the Food Standards Agency's approved list for Great Britain, carried over from EU law at the end of the Brexit transition period. European reviews published since then are not automatically adopted in Great Britain.
- Permitted foods
- Flavoured soft drinks · Reduced-energy or no-added-sugar jams and marmalades · Reduced-energy or no-added-sugar sweets · Chewing gum · Reduced-energy or no-added-sugar ice cream and ice lollies · Reduced-energy or no-added-sugar breakfast cereals · Some reduced-energy baked goods (current uses only) · Weight-control foods · Sweetener tablets and powders
- Maximum levels
- Set for each type of food, for example 400mg per litre in flavoured soft drinks.
- History
- Sucralose was first approved in the EU under the 1994 sweeteners directive and carried into UK law at the end of the Brexit transition in December 2020. European reviewers completed a full review in 2026, kept the daily limit and current uses, and could not confirm the safety of extending it to more baked goods. The FSA has not formally adopted that review. European opinions are not automatically adopted in Great Britain, though the FSA may act case by case.
Who should be careful
People who often eat sucralose-sweetened baked goods, such as cakes, biscuits or protein bars heated during manufacture, may be taking in breakdown products that regulators have not been able to clear. People watching their blood sugar or insulin, including those at risk of type 2 diabetes, should know about the trial evidence on insulin. Look for sucralose or E955.
The honest read
The 2026 European review kept its approval for current uses. But two threads in the research are now harder to wave away. Human trials show regular sucralose changes gut bacteria and measurably reduces insulin sensitivity. And what happens when it is heated in baking has been left open by regulators rather than settled. Both matter more for someone eating sucralose-sweetened baked goods every day than for an occasional diet drink.
Common questions about sucralose
What is sucralose?
Sucralose (E955) is a calorie-free man-made sweetener about 600 times sweeter than sugar. It is made from sugar by swapping three parts of the molecule for chlorine atoms. It is the sweetener in Splenda.
Is sucralose bad for you?
It has no calories. But the research has moved on. A 2025 randomised trial found 30 days of sucralose cut insulin sensitivity by about a fifth in healthy adults, and human studies show it changes gut bacteria. It is approved in the UK and EU, but no calories is not the same as no effect, and that matters most for daily use.
Does sucralose raise blood sugar?
In a 2025 trial, a month of daily sucralose lowered insulin sensitivity and raised blood sugar and insulin after a test meal. Regular use may affect how your body handles sugar over time.
Has sucralose been fully cleared by regulators?
It is approved in the UK and EU. But in 2026 European reviewers could not confirm its safety in more baked goods, and the recent human trials on insulin and gut bacteria are not yet reflected in the rules. Approved is not the same as settled.
Is sucralose an artificial sweetener?
Yes. It is a man-made, high-intensity sweetener made by chemically changing sugar. It is not a natural sweetener like stevia, and it is not a sugar, even though it is made from one.
Is E955 banned in the UK?
No. Sucralose is approved in the UK and is on the Food Standards Agency's list. The 2026 European review kept its current EU uses but did not approve extending it to more baked goods. The UK approval rests on the rules inherited from the EU, and the FSA has not separately adopted the 2026 review.
Does sucralose affect insulin?
Human trials suggest it can. In a 2025 randomised trial, 30 days of sucralose in healthy adults cut insulin sensitivity by about 20% compared with a dummy. How it works is not fully proven, but sweet receptors in the gut and changes in gut bacteria are the leading explanations.
What foods contain E955?
Diet fizzy drinks, sugar-free squash, flavoured water, reduced-sugar yoghurts, protein bars and shakes, chewing gum, sugar-free jams and sauces, and some lower-sugar baked goods. Splenda sweetener is mainly sucralose.
Is E955 vegan?
Yes. It is made from sugar by a chemical process, with nothing from animals.
Sources
- EFSA re-evaluation of sucralose (E955) as a food additive, 2026
- EFSA news: EFSA finds sucralose safe when used as currently authorised, cannot confirm safety of extending its use
- UK FSA regulated products register: E-955 sucralose
- UK FSA food additives authorisation guidance: post-Brexit re-evaluation programme not in assimilated law
- Sucralose consumption modifies glucose homeostasis, gut microbiota, Curli protein and related metabolites in healthy individuals: randomised placebo-controlled triple-blind trial, Clinical Nutrition ESPEN, 2025
- Ten-Week Sucralose Consumption Induces Gut Dysbiosis and Altered Glucose and Insulin Levels in Healthy Young Adults, Frontiers in Nutrition / PubMed PMC8880058, 2022
- Gut Microbiome Response to Sucralose and Its Potential Role in Inducing Liver Inflammation in Mice, Journal of Toxicology and Environmental Health / PMC5522834, 2017
Last reviewed: 9 November 2026
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