Aspartame
The short version
An intense low-calorie sweetener about 200 times sweeter than sucrose, used in diet beverages.
A low-calorie sweetener. It's approved and fine for most people, but those with the rare condition PKU must avoid it, and in 2023 the WHO's cancer agency listed it as 'possibly carcinogenic' — a weak, debated classification. Those open questions are why we flag it.
Safety profile
ADI of 40 mg/kg body weight (EU). In 2023 the IARC classified aspartame as 'possibly carcinogenic' (Group 2B), while JECFA reaffirmed the ADI. People with phenylketonuria (PKU) must avoid it since it contains phenylalanine — explicit warning labels are mandatory.
Sources
- EFSA — Aspartame topic page (full re-evaluation of E 951, December 2013; page last reviewed 10 Sep 2026) — European Food Safety Authority, 2013. EU ADI 40 mg/kg bw/day; ADI not applicable to PKU patients
- WHO — Aspartame hazard and risk assessment results released (IARC and JECFA, 14 July 2023) — World Health Organization, 2023. IARC Group 2B (2023) and JECFA reaffirmed ADI 40 mg/kg
- 21 CFR 172.804 — Aspartame (eCFR, current to 13 Oct 2026) — US Office of the Federal Register / FDA, 2026. Mandatory US phenylketonuria label statement
- FDA — Timeline of Selected FDA Activities and Significant Events Addressing Aspartame (content current as of 30 May 2023) — US Food and Drug Administration, 2023. US approval history (1974 approval, 1975 stay, 1981 dry foods); US ADI 50 mg/kg set 1983
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.