Aspartame (E951) β€” What You Need to Know

Questionable(4/10)Synthetic

The score is an eNumbers.org editorial summary, not an official agency rating or medical advice. Start with the regulatory status and primary sources below.

What Is Aspartame?

Aspartame is a low-calorie artificial sweetener approximately 200 times sweeter than sugar. It was discovered accidentally in 1965 by James M. Schlatter while he was working on an anti-ulcer drug. It is one of the most studied food additives in history, yet remains one of the most controversial. In July 2023, the World Health Organization's International Agency for Research on Cancer (IARC) classified aspartame as 'possibly carcinogenic to humans' (Group 2B), creating significant public concern, though the WHO's separate nutritional body (JECFA) maintained its ADI.

What Is It Used For?

Used as a sugar substitute in diet soft drinks, tabletop sweeteners, chewing gum, yogurt, and many 'sugar-free' products. Degrades at high temperatures, so it is not suitable for baking.

Function: Intense artificial sweetener
4 mg
Dataset exposure estimate
2800 mg
ADI-derived reference (70 kg)
0.1%
of ADI (typical diet)

Exposure figures are population-level references, not personal limits. Actual intake varies by diet, product and jurisdiction.

Regulatory & Editorial Context

πŸ“Š
Acceptable Daily Intake (ADI)
40 mg/kg bw/day
πŸ›οΈ
Regulatory Status
πŸ‡ͺπŸ‡Ί EU: Authorized
πŸ‡ΊπŸ‡Έ US: Approved
πŸ‡―πŸ‡΅ JP: Approved
πŸ‡¦πŸ‡Ί AU: Approved
πŸ‡¨πŸ‡¦ CA: Approved
⚠️ Key Concerns

Aspartame is contraindicated for people with phenylketonuria (PKU), a rare genetic disorder, because it contains phenylalanine. In July 2023, IARC classified aspartame as Group 2B ('possibly carcinogenic to humans') based on limited evidence from observational studies showing associations with hepatocellular carcinoma. The JECFA (WHO/FAO's food additives committee) simultaneously reviewed the evidence and maintained the ADI of 40 mg/kg bw/day, stating the evidence was 'not convincing' enough to change safe intake levels. The FDA also maintained its position that aspartame is safe. The Group 2B classification is the second-lowest category of carcinogenic hazard and includes many common substances including pickled vegetables and aloe vera extract. The debate continues and ongoing research is warranted.

Editorial context score

eNumbers.org currently assigns Aspartame an editorial context label of Questionable with a score of 4/10. This is 1.8 points below the database average for sweeteners (5.8/10). Dataset reference year: 2023. The dataset's population estimate equals about 0.1% of the listed ADI.

This score is not issued by EFSA, FDA, WHO or another regulator.

Commonly Found In

Diet sodaSugar-free gumTabletop sweetenersSugar-free yogurtDiet iced tea
Example brands:
Diet CokeDiet PepsiNutraSweetEqual

Always check the label for E951 or 'Aspartame'

β–ΆChemical Information
Formula: C14H18N2O5
Molecular Weight: 294.3 g/mol
CAS Number: 22839-47-0
INS Number: 951
Also known as: E951, INS 951, NutraSweet, Equal, APM, N-(L-Ξ±-Aspartyl)-L-phenylalanine 1-methyl ester

Primary Sources

Source review: 2026-08-08

Official references relevant to this page. Check the agency record for current permitted uses, limits and jurisdiction-specific wording.

How eNumbers.org uses sources β†’

Frequently Asked Questions about Aspartame

Current dataset status: FDA β€” Approved; EFSA/EU β€” Authorized. Reported concerns: Aspartame is contraindicated for people with phenylketonuria (PKU), a rare genetic disorder, because it contains phenylalanine. In July 2023, IARC classified aspartame as Group 2B ('possibly carcinogenic to humans') based on limited evidence from observational studies showing associations with hepatocellular carcinoma. The JECFA (WHO/FAO's food additives committee) simultaneously reviewed the evidence and maintained the ADI of 40 mg/kg bw/day, stating the evidence was 'not convincing' enough to change safe intake levels. The FDA also maintained its position that aspartame is safe. The Group 2B classification is the second-lowest category of carcinogenic hazard and includes many common substances including pickled vegetables and aloe vera extract. The debate continues and ongoing research is warranted. Regulatory status and individual risk are not the same; check the primary sources and permitted conditions of use.

Quick Facts

E-Number
E951
INS Number
951
Category
Sweeteners
Origin
Synthetic
FDA Status
Approved
EFSA Status
Authorized
ADI
40 mg/kg bw/day
Dataset Review
2023
Ingredient-level Dietary Notes
Vegan: βœ… YesHalal: βœ… YesKosher: βœ… YesGluten-Free: βœ… Yes

Carriers, processing aids and product certification can change suitability. Verify the final label and certifier.

Disclaimer: This information is for educational purposes only and is not medical advice. Always consult a healthcare professional for health-related decisions.

Related Additives

Other sweeteners in the same family