Is Aspartame in Flavored Water? What You Need to Know

December 10, 2025 •

3 min read

Over 6,000 products worldwide contain the artificial sweetener aspartame. While often found in diet sodas and other sugar-free drinks, many consumers wonder if this additive is also a common ingredient in flavored water. The answer is yes, but it depends entirely on the brand and product line.

Quick Summary

Yes, many flavored water products contain aspartame, particularly those labeled as "diet" or "zero-calorie," while many others use alternative sweeteners or natural fruit essences. Checking the product's ingredient list is the most reliable way to determine if a specific flavored water contains aspartame.

Key Points

Check the Label: Always inspect the ingredient list for "aspartame" or its E-number, E951, to confirm its presence in flavored water.
Look for 'Diet' or 'Zero-Calorie': Aspartame is most commonly used in flavored water products labeled as sugar-free or diet.
Distinguish from Natural Flavors: The presence of "natural flavors" on a label does not guarantee the absence of artificial sweeteners.
Consider Alternatives: Brands like Hint and Waterloo use only natural essences, while others may use sweeteners like stevia or sucralose.
Note Regulatory Classifications: While regulatory bodies like the FDA affirm aspartame's safety within limits, the WHO's IARC classifies it as a possible carcinogen, highlighting ongoing debate.
DIY is an Option: For full control over ingredients, try making your own flavored water with fruit and herbs.

Identifying Aspartame in Flavored Water

To find out if your flavored water contains aspartame, the most important step is to read the nutrition label. Manufacturers are required to list all ingredients, including artificial sweeteners. Look for the name "aspartame" or its E-number, E951. For individuals with phenylketonuria (PKU), labels will also carry a mandatory warning: "PHENYLKETONURICS: CONTAINS PHENYLALANINE," since aspartame contains this amino acid.

Where Aspartame is Most Likely Found

Aspartame is a popular choice for sweetening drinks because it is approximately 200 times sweeter than sugar and contains very few calories. Consequently, it is most often included in product lines that are marketed as 'zero-calorie,' 'diet,' or 'sugar-free'. The stable chemical structure of aspartame is well-suited for the long shelf life of most packaged beverages. However, some manufacturers opt for other sweeteners to avoid aspartame's controversial reputation and reported aftertaste.

Reading the Label Beyond the Front

Do not rely solely on front-of-package claims like "natural flavors" or "zero sugar." The term "natural flavors" can still appear alongside artificial sweeteners on the ingredients list. A truly natural, sugar-free, artificially sweetened beverage will explicitly state its sweetener source, whether it's stevia, monk fruit, or another option. The ingredients list is the only definitive source of information.

Comparison of Flavored Water Sweeteners

This table outlines the key differences between common sweeteners used in flavored water, helping you understand what to look for when shopping.


Feature	Aspartame	Sucralose	Stevia	Natural Fruit Essence
Calorie Content	Low-calorie (minimal)	Zero-calorie	Zero-calorie	Zero-calorie
Sweetness	~200x sweeter than sugar	~600x sweeter than sugar	~200-400x sweeter than sugar	Mild to no sweetness
Source	Synthetic (from amino acids)	Synthetic (chlorinated sugar)	Plant-based	Extracted from natural fruits
Brand Names	NutraSweet, Equal	Splenda	Truvia, PureVia	Common in many brands
Common Use	Diet sodas, powdered mixes, some flavored water	Zero-calorie beverages, baked goods	Naturally sweetened drinks	Seltzers, fruit-infused waters
Stability	Not heat-stable	Heat-stable	Heat-stable	Highly stable

Flavored Water Alternatives without Aspartame

If you prefer to avoid aspartame, numerous flavored water options are available that use different sweeteners or rely solely on natural fruit essences.

Brands with Natural Sweeteners

Hint Water: Infused with natural fruit essences, containing zero calories and no artificial sweeteners.
Volvic Touch of Fruit Sugar Free: Uses a mix of fruit flavorings and often another sweetener besides aspartame.

Sparkling Waters with Natural Flavors

Many sparkling water brands achieve flavor through natural essences or fruit oils, not sweeteners. These products are typically calorie and sugar-free.

Waterloo Sparkling Water: Uses natural flavors and contains no sugar or artificial sweeteners.
La Croix: Flavored with natural essence oils, providing flavor without sugar or sweeteners.

The DIY Approach: Infused Water

Making your own flavored water is the most controlled way to ensure it is free of aspartame and any other additives. Simply add slices of fruit, cucumber, or herbs to a pitcher of still or sparkling water and let it infuse. Popular combinations include lemon and mint, strawberry and basil, or cucumber and lime.

A Note on Controversies and Regulations

The safety of aspartame has been a subject of extensive research and debate for decades. Organizations like the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have repeatedly confirmed its safety for general consumption within established acceptable daily intake (ADI) levels. For example, a 150-pound person could consume a dozen cans of diet soda daily without exceeding the ADI. However, the World Health Organization's International Agency for Research on Cancer (IARC) has classified aspartame as "possibly carcinogenic to humans" (Group 2B), a classification based on limited evidence. This does not indicate a widespread danger at normal consumption levels, but rather highlights the need for continued research. For individuals with phenylketonuria (PKU), aspartame should be strictly avoided. For others, making an informed choice involves considering the available science and personal health preferences.

Conclusion

Yes, aspartame can be an ingredient in flavored water, particularly in products marketed as zero-calorie or diet options. Consumers must check the ingredient list to confirm the presence of aspartame, as well as other sweeteners like sucralose or stevia. For those looking to avoid this specific artificial sweetener, many brands offer alternatives using natural flavors or different sugar substitutes. Ultimately, understanding product labeling empowers you to make informed decisions about your beverage choices based on personal health goals and preferences.

Frequently Asked Questions

No, aspartame is not in all flavored water. It is typically found in diet, zero-calorie, or sugar-free varieties. Many brands use other sweeteners or natural fruit essences instead.

To know for certain, check the ingredients list on the product label. Aspartame is listed by name or as E951 in Europe. If you have PKU, the label must also state that it contains phenylalanine.

Phenylalanine is one of the amino acids that make up aspartame. It is important because individuals with the genetic disorder phenylketonuria (PKU) cannot properly metabolize it and must avoid aspartame.

Yes, several brands, including Hint Water and Waterloo Sparkling Water, use natural fruit essences for flavor instead of artificial sweeteners.

Regulatory bodies like the FDA and EFSA have determined that aspartame is safe for most people when consumed within acceptable daily intake (ADI) levels. However, the WHO's IARC classifies it as 'possibly carcinogenic,' and it should be avoided by individuals with PKU.

Besides aspartame, other common artificial sweeteners include sucralose (Splenda), acesulfame potassium (Ace-K), and plant-based stevia derivatives.

Plain seltzer or sparkling water does not contain aspartame. However, flavored seltzer products may or may not, so it is necessary to check the label.