E955

Sucralose (Splenda)

Last reviewed: 11 May 2026

Chlorinated, heat-stable sweetener used across UK baking products, protein bars and reduced-sugar foods.

What it is

E955 is sucralose, made by selectively replacing three hydroxyl groups on a sucrose molecule with chlorine atoms. Discovered in 1976; approved in the UK from 2004 and in the US by the FDA in 1998.

• About 600 times sweeter than sucrose
• Zero calories — 85–95% passes through the gut unchanged
• Heat-stable enough for most cooking applications (with the caveat above on high-temperature breakdown)
• Sugar-like sweetness profile with much less aftertaste than saccharin or stevia
• The dominant sweetener in UK baking-targeted products and protein bars where aspartame's heat instability would fail

Where you'll see it on a UK label

Foods that need heat-stable sweetness

• Protein bars and reduced-sugar baked goods
• Reduced-sugar cereals and granola
• Low-sugar jams, sauces and syrups
• Sugar-free chewing gum and mints
• Reduced-calorie ice cream and yoghurts

Drinks

• Some diet soft drinks (often in blends with acesulfame K)
• Sugar-free energy drinks
• Protein shakes and meal-replacement drinks

Table-top sweeteners

• Splenda (yellow packets)
• Some Canderel variants

Non-food

• Toothpaste, mouthwash, chewable vitamins, liquid medicines

What the science shows

DNA damage — the 2023 Schiffman et al. paper

A 2023 paper from researchers at North Carolina State and the University of North Carolina (Schiffman et al., Journal of Toxicology and Environmental Health Part B) characterised sucralose-6-acetate — a minor metabolite and contaminant — and reported it caused DNA strand breaks in cultured human cells at levels detectable in commercial sucralose batches. The paper called for regulatory review and was widely covered in UK media. JECFA acknowledged the need for further evaluation in subsequent communications. EFSA's existing opinion has not been formally revised at the time of writing. This is a recent signal in a previously cleaner dossier — the honest framing is that the toxicology questions are more active than the older approval narrative suggested.

Gut bacteria

A 2018 study reported reductions in beneficial gut bacteria (notably Bifidobacteria) with sucralose intake; follow-on animal work has shown microbiome shifts that persisted for weeks after exposure ended. Human trials are mixed and generally short. The microbiome question recurs across non-nutritive sweeteners; the dose, baseline microbiome and study length all appear to matter.

Glucose and insulin response

Despite passing through largely unmetabolised, sucralose has shown effects on insulin response in some short human trials, particularly when consumed with carbohydrate. The clinical significance for people with or at risk of type 2 diabetes is unsettled. The simple "no-calorie, no-effect" framing isn't supported by the more recent data.

High-temperature breakdown

Sucralose decomposes above ~120°C, generating chloropropanols and at higher temperatures trace polychlorinated dibenzo-p-dioxins (PCDDs). The BfR (Germany) issued a 2019 warning about high-temperature baking applications. Real-world exposure depends heavily on the product matrix and cooking conditions — a low-sugar ready meal reheated in a microwave is a very different exposure to a sucralose-only baking blend at 200°C.

Regulatory status

UK/EU: Approved (E955). ADI 15mg/kg body weight per day (EFSA).

US: FDA approved 1998 (general use).

JECFA: 2023 communication acknowledged the need for further review in light of the Schiffman et al. data on sucralose-6-acetate. EFSA's existing opinion has not been formally revised at the time of writing.

BfR (Germany): 2019 advisory against using sucralose in high-temperature cooking applications.

Reading a UK label

Look for "sucralose", Splenda or E955 in the ingredient list. Sucralose dominates the categories where aspartame can't survive (baking, long-shelf-life sauces, protein bars) — if a reduced-sugar product is meant to be cooked or has been heat-processed, sucralose is more likely than aspartame. At the 15mg/kg ADI, a 70kg adult's daily limit is 1,050mg — about 70 sachets of Splenda — well above any normal dietary intake. The ADI isn't where the recent toxicology questions sit; the sucralose-6-acetate work is about the molecule itself, not the dose threshold.

Last updated: 11 May 2026