What Are Functional Beverages?

The term sounds official. It is not. Here is what it means, how the rules work, and what to check on a can.

"Functional beverage" is one of those terms that sounds like a regulatory category and is really a marketing one. If you have wondered what are functional beverages, and what separates them from soda or juice, this guide covers the definition, the rules that actually apply, and a short checklist for reading a can.

What are functional beverages?

They are drinks sold on the idea that they do more than quench thirst or supply calories.

A 2024 editorial in the journal Foods defines functional foods and beverages as products that "encompass raw, cooked, or processed edible substances that provide health benefits beyond basic nutrition" [1]. The Academy of Nutrition and Dietetics describes functional foods more simply, as foods that can have a beneficial health effect when eaten regularly and in certain amounts, and says minimally processed whole foods as well as fortified or enhanced foods can qualify [2].

That second point matters. By that broad definition, orange juice or yogurt might count. In practice, the shelf label "functional beverage" usually means a drink with something added: a botanical extract, an adaptogen, extra vitamins, electrolytes, probiotics, or a plant compound such as kanna. The added ingredient is the selling point.

Is "functional beverage" a legal category?

No. The Academy of Nutrition and Dietetics states that "there is currently no legal definition for functional food," and that the FDA regulates the label claims such foods carry [2].

FDA says the same thing in a guidance document on complementary and alternative medicine products: "functional foods" are not defined as a regulatory product category, and a product of that kind would be regulated as either a food or a drug, depending on its claims [3]. So a company can call a drink "functional" freely. What it cannot do is make claims that are false or misleading, and FDA considers a product's labeling, advertising and other representations when deciding what the product is [4].

Is a functional drink a food or a supplement?

Usually a conventional food, because the law treats beverages as conventional foods.

This is the part most shoppers never hear about. FDA's 2014 guidance on distinguishing liquid dietary supplements from beverages says that a dietary supplement is a product that "is not represented for use as a conventional food," and that beverages are conventional foods [4]. A liquid can be represented as a conventional food through its name, packaging, serving size, recommended daily intake, composition, directions for use and marketing. The guidance gives examples:

• Names with food terms such as "drink," "water" or "soda" can represent a product as a conventional food [4].
• Packaging resembling common beverage containers, such as a pop-top aluminum can, can imply a single-serving soft drink [4].
• A product that has a Supplement Facts panel may still be a conventional food if its statements say it is meant to "refresh" or "rehydrate" [4].

The guidance is nonbinding, and FDA says it looks at a combination of factors in context [4]. We are not lawyers, and we are not saying any particular brand is misclassified. We are saying that "can of fizzy drink" and "dietary supplement" sit in some tension, which is why powders, liquid concentrates and capsules are the more usual supplement formats.

The ingredient rules differ too. FDA explains that a substance added to a conventional food must generally be used under a food additive regulation, be generally recognized as safe (GRAS) for that use, or fit another exception. A dietary ingredient in a supplement does not have to be GRAS, but ingredients not marketed in the U.S. before October 15, 1994 are "new dietary ingredients" with their own notification requirements [4]. FDA also notes that an ingredient lawful in a supplement may not be lawful in a soft drink [4]. We did not verify how each kanna drink on the market handles this question, and you will not find the answer on the front of the can.

Does anyone approve these drinks before sale?

Not in the way people assume.

FDA says it "does NOT have the authority to approve dietary supplements for safety and effectiveness" before they are sold, and that it is the responsibility of supplement companies to make sure their products meet safety standards [5]. FDA also says that, in many cases, firms can sell supplements without notifying the agency, and that the FTC reviews the truth and accuracy of supplement advertising [7]. For conventional foods, the pathway is different, as described above, but there is no agency review of a drink's marketing claims before it ships.

The practical point: "functional" on a can is not an endorsement from anyone. It is a brand's description. The rest is up to you and, if you take medicines, your clinician.

What kinds of functional drinks are there?

This is our own shorthand rather than an official taxonomy, since no official one exists. Roughly, shoppers run into these groups:

Our non-alcoholic kanna drink comparisons live on the ranking page. Other plants in this space, like kava, have their own safety stories; see kanna vs kava.

How do you read a functional drink label?

Look at the dose, the form of the ingredient, and whether anyone has studied it in people at that amount.

1. Find the milligram amount. A blend that lists ingredients without amounts, sometimes called a proprietary blend, tells you very little.
2. Check the extract type. "Extract" is not one thing. NCCIH cautions that "standardized," "verified" or "certified" on a supplement label does not necessarily guarantee quality or consistency, and that what is on the label may not be what is in the product [6].
3. Compare with studied doses. A trial that used 25 mg of one specific extract does not tell you what a different extract at a different dose does. Our kanna dosage page walks through this.
4. Look at the facts panel. A "Supplement Facts" panel and a "Nutrition Facts" panel are not the same, and FDA says the panel alone does not settle a product's category [4]. It still tells you how the brand is presenting the product.
5. Scan for medicine warnings. NCCIH notes that supplements may interact with your medications [6]. A responsible brand lists them.
6. Read the claims with a skeptical eye. Absolute phrases like "proven" or any claim about a medical condition should make you look harder. Study results apply to the product that was studied.

Where do kanna drinks fit?

Kanna is a typical functional ingredient: a plant with a long traditional history and a small body of human research, now added to cans.

The human studies used a standardized extract called Zembrin, in small groups of healthy adults, at doses around 8 to 25 mg [8]. A 2026 review described the evidence as mixed [9]. We summarize it in what the studies show rather than repeating it here. Kanna also has a medicine-interaction caution: WebMD lists SSRIs, SNRIs, MAOIs, tricyclics, antipsychotics, triptans and St. John's wort as concerns, and says it is not known how sceletium affects pregnancy [10].

As a transparency note, kannadrinks.com is published by Psilly Goose, whose Silly can lists 35 mg of kanna (without stating the extract's standardization), 3,000 mg of lion's mane, 40 calories and no caffeine; see where it lands on our ranking. Whatever brand you consider, run it through the checklist above first. For a look at how capsules and tinctures compare with cans, see kanna drinks vs capsules, and for the other ingredient in many of these cans, see kanna and lion's mane.

This page is general information, not medical advice or legal advice. These statements have not been evaluated by the FDA. Functional beverages are not intended for any disease or health condition.

References

1. Abbasi AM, Guo X, Chen Y. Functional properties of foods and beverages (editorial). Foods 2024;13(17):2763. PubMed Central
2. Academy of Nutrition and Dietetics. Functional foods. eatright.org
3. U.S. Food and Drug Administration. Guidance for industry: Complementary and alternative medicine products and their regulation by the Food and Drug Administration (footnote on "functional foods"). fda.gov
4. U.S. Food and Drug Administration. Guidance for industry: Distinguishing liquid dietary supplements from beverages. January 2014. fda.gov
5. U.S. Food and Drug Administration. FDA 101: Dietary supplements. fda.gov
6. National Center for Complementary and Integrative Health. Using dietary supplements wisely. nccih.nih.gov
7. U.S. Food and Drug Administration. Information for consumers on using dietary supplements. fda.gov
8. Nell H, et al. A randomized, double-blind, parallel-group, placebo-controlled trial of Extract Sceletium tortuosum (Zembrin) in healthy adults. J Altern Complement Med 2013;19(11):898-904. PubMed
9. de Jong M, et al. Mesembryanthemum tortuosum and Zembrin: mixed evidence from in vivo animal and clinical studies on their antidepressant and anxiolytic effects. Planta Med 2026;92(8):806-823. PubMed
10. WebMD. Sceletium: Uses, side effects, interactions. webmd.com

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