Aspartame safety depends on established daily intake limits rather than a single "dangerous" dose. The most widely cited safe limits are:

• Acceptable Daily Intake (ADI): 40 mg per kilogram of body weight per day (JECFA/EFSA standard). At this level, exposure is considered protective for the general population. For example, a 70 kg person could safely consume about 2,800 mg per day under this limit, though typical dietary exposure is much lower. This ADI has been reaffirmed by major health authorities, and real-world exposures are generally well below it. [ADIs and safety assessments are consistently reported by EFSA and WHO/FAO experts]
• Some regulatory bodies, notably the FDA in the United States, have used a slightly higher point of reference for labeling and regulation, commonly cited as about 50 mg per kg of body weight per day. In practice, most people’s daily intake remains well below this level. [Regulatory summaries and health agency statements]

How to interpret your personal risk

• Typical daily exposure: For the average consumer, daily intake from diet beverages, sugar-free products, and tabletop sweeteners tends to be far below the ADI of 40 mg/kg/day. Estimates cited by health authorities often place average consumer exposure at roughly a third or less of the ADI, though high-end consumers who ingest many products containing aspartame could approach the upper safety margins. [Exposure assessments from EFSA and WHO reports]
• Carcinogenicity assessment: The International Agency for Research on Cancer (IARC) classified aspartame as possibly carcinogenic to humans (Group 2B), based on limited evidence in humans. This does not specify a safe level, but it informs risk awareness at very high or cumulative exposures. Regular dietary exposure within established ADIs is still considered unlikely to pose a clear cancer risk according to current international evaluations. [IARC and JECFA/EFSA assessments]

Practical guidance

• If you weigh 70 kg, consuming up to about 2,800 mg of aspartame per day would be within the 40 mg/kg ADI (per EFSA/JECFA). This roughly translates to several liters of diet soda per day, depending on the product’s aspartame content. Real-world products typically contain lower amounts per serving, so reaching the ADI would require unusually high intake across many products. [ADI calculations and example references]
• If you have special health concerns, such as pregnancy, phenylketonuria (PKU), or specific medical conditions, you should follow medical guidance from your healthcare provider, as individuals with PKU must monitor phenylalanine intake, since aspartame releases phenylalanine when metabolized. [PKU guidance and general safety notes]

Bottom line

• There isn’t a single “dangerous dose” for aspartame; safety is defined by daily intake limits. For the general population, staying well below the ADI (40 mg/kg/day) is considered protective, while values around 50 mg/kg/day are used by some regulatory frameworks. If you’d like, provide your weight and typical daily intake, and a rough estimate can be calculated to show how your exposure compares to these guidelines. [ADI references and regulatory summaries]