Is Aspartame Bad for You?
Two World Health Organization bodies looked at it in July 2023 and reached different kinds of conclusions. The International Agency for Research on Cancer classified aspartame as possibly carcinogenic to humans, Group 2B, on the basis of limited evidence for cancer in humans, specifically for hepatocellular carcinoma, a type of liver cancer, along with limited evidence in experimental animals. JECFA concluded the data gave no sufficient reason to change the acceptable daily intake of 0 to 40 mg per kilogram of body weight.
For scale, the WHO said an adult weighing 70 kg would need to drink more than 9 to 14 cans a day of a diet soft drink containing 200 or 300 mg of aspartame to exceed that intake, assuming no other intake from other foods. The FDA says it disagrees with IARC’s conclusion that the studies support classifying aspartame as a possible carcinogen to humans, and that its scientists identified significant shortcomings in the studies IARC relied on.
Aspartame has to be named in the ingredient list, and the FDA says the label must include a statement telling people with phenylketonuria, or PKU, that the product contains phenylalanine. Federal rules require that statement on the principal display panel or the information panel of any food containing aspartame.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceIARC classified aspartame as possibly carcinogenic to humans (Group 2B) on the basis of limited evidence for cancer in humans, specifically for hepatocellular carcinoma, a type of liver cancer, and limited evidence in experimental animals. World Health Organization, IARC and JECFA ↗
- Government sourceJECFA concluded that the data evaluated gave no sufficient reason to change the previously established acceptable daily intake for aspartame of 0 to 40 mg per kilogram of body weight. World Health Organization, IARC and JECFA ↗
- Government sourceThe WHO said a 70 kg adult would need to drink more than 9 to 14 cans a day of a diet soft drink with 200 or 300 mg of aspartame to exceed the acceptable daily intake, assuming no other intake. World Health Organization, IARC and JECFA ↗
- Government sourceThe FDA says it disagrees with IARC’s conclusion that the studies support classifying aspartame as a possible carcinogen, and that its scientists identified significant shortcomings in the studies IARC relied on. US FDA ↗
- Government sourceThe FDA says consumers can find aspartame by name in the ingredient list, and that the label must include a statement informing people with PKU that the product contains phenylalanine. US FDA ↗
- Regulatory filingUnder 21 CFR 172.804, the label of any food containing aspartame must carry a statement for phenylketonurics that it contains phenylalanine, on the principal display panel or the information panel. eCFR, 21 CFR 172.804 ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.