Functional Beverages: What Actually Moves Units

Functional beverages are drinks sold on a benefit rather than on flavor: energy, hydration, protein, digestive health, focus. That definition is doing a lot of work, because where you draw its edge decides whether the category is worth $50 billion or $200 billion, and every published market-size figure draws it somewhere different.

The more useful question for anyone buying or selling into this set is narrower. Which functional claims actually move units, at what price, and do they still move when the promotion stops. That is answerable from transactions, and the answer is less flattering to the category than the trend decks are.

Key takeaways

• The functional set is five sub-sets with different economics: energy, hydration and electrolyte, protein, gut health, and focus or nootropic. Averaging them produces a number that describes none of them.
• Functional items over-index on dollars far more than on units, because the claim carries a price premium. That is the category's real economic argument.
• Rank claims by non-promoted velocity per item, not by growth rate. Several functional sub-sets sell more slowly than the unclaimed rest of the cooler once you strip the deal weeks out.
• Cold placement is the confound. An ambient functional item and a cold one are not comparable, and most launch post-mortems in this category are really placement post-mortems.
• A velocity read is not a health claim. Transactions show what sold; they say nothing about whether a benefit was delivered or a shopper believed it.

What counts as a functional beverage

There is no regulatory definition, which is exactly why the market sizes disagree. The working definition that survives contact with a planogram is this: a packaged non-alcoholic drink whose front panel sells a physiological benefit, where the benefit is the reason for the price rather than an afterthought on a flavor.

Two of those sub-sets are big enough to deserve their own reads and will get them: energy, which is the only sub-set that beats the unclaimed cooler on non-promoted velocity, and protein. This page is about the set as a whole and about the one comparison you cannot make from a market-size report: which functional claims actually move units once they are on your own shelf.

Why the published functional beverages numbers disagree

A figure worth citing carries its source and its period. Research and Markets put the global functional beverage market at $154.44 billion in 2023, growing at 5.5% a year over 2018 to 2023, and projected $204.74 billion by 2028 at 6.3% a year, as reported by FoodNavigator in January 2025. That is a global number on a definition the report chose, and any US figure quoted next to it is measuring a different thing.

You will find US market sizes ranging from roughly $50 billion to over $65 billion for the same year, from research firms selling reports at four figures. The spread is not sloppiness. It is the definition: include or exclude bottled water with added vitamins, RTD coffee, sports drinks and the fortified end of juice, and you can move the number by tens of billions without measuring anything differently. Quoting one of those in a buyer meeting is a risk with no upside, because the buyer has Circana and you do not know which definition your number used.

Sourced figures that do tell you something, because their boundaries are stated: Circana reported that soft drinks carrying prebiotic fiber, botanical blends, adaptogens, added vitamins or low-sugar formulations were outpacing traditional diet sodas at double-digit annual growth, reported by FoodNavigator in July 2025. In the same period PepsiCo acquired Poppi for $1.95 billion in May 2025, and Olipop was valued at $1.85 billion in a February 2025 funding round. Those are transactions rather than estimates, and they tell you what the category's own operators believe.

The claim is not the category

Here is the read that first-party point-of-sale supports and a market-size report cannot. Tag every item in the packaged beverage set with its front-panel functional claim, then compare velocity per item in the same stores over the same period, and equivalize the price so a 12 oz can and a 20 oz bottle are comparable. See equivalized volume if that step is unfamiliar; skipping it is the most common way this analysis goes wrong.

A worked example across 212 grocery and convenience doors, 52 weeks, all units expressed as 12 oz equivalents.

The headline reconciles three ways. Functional items are 107 of the 250 items in the set, or 42.8%. They are 214.4 of the 450.9 units, or 47.6%. And at a weighted $1.72 per equivalized 12 oz against $0.94 for everything else, they are $369 of the set's $592 in weekly dollars per store, or 62.4%. Forty-three percent of the items, forty-eight percent of the units, sixty-two percent of the dollars. That progression is the honest commercial case for functional beverages, and it is stronger than the growth rates usually quoted for them.

Which functional claims move units without a promotion

Now strip the deal weeks out. Multiply velocity per item by the share of units that were not on promotion and you get the number that predicts whether an item survives its next line review.

Sorted that way, only energy beats the unclaimed rest of the cooler. Every other functional sub-set sells fewer non-promoted units per item than an ordinary flavor-led beverage in the same doors, and two of them, gut health and nootropic, are selling half or more of their volume on deal. A buyer looking at raw growth rates sees five winners. A buyer looking at this column sees one clear winner in energy, one honest builder in protein, a hydration set at rough parity with an ordinary beverage, and two sub-sets whose volume is mostly rented.

Protein is the interesting middle. It is slower than the unclaimed set, but it moves 71% of its units at full price, which is the highest share in the table. An item that sells slowly at full price and an item that sells quickly on constant deal have completely different futures, and only one of them survives a margin review. This is the same logic as baseline sales applied at claim level.

The three ways this read goes wrong

• Cold versus ambient. A functional item on an ambient shelf next to one in a cold door is not a fair comparison, and reading their velocities side by side will tell you a product failed when it was never given the same chance. Segment by placement before drawing any conclusion.
• Distribution masquerading as demand. When a sub-set grows 40%, decompose it: did items per store rise roughly in line with dollars, or did dollars rise on stable item counts? The first is a reset, the second is demand. Entering a category on the first signal, two years late, at full slotting cost, is how this goes badly.
• Unequivalized price. Functional packs run small and expensive. A raw average retail across a set containing 12 oz cans and 28 oz bottles is arithmetic, not information.

Where the set actually sits, and why that decides its economics

Almost all functional volume is cold-vault volume, and the cold vault is the most contested space in the store. NACS reported that packaged beverages accounted for 18.7% of convenience in-store sales in 2025, up 0.8 points on 2024, and that packaged beverages and beer together made up just over a quarter of both in-store sales and in-store gross profit, with packaged beverages carrying over 80% of that profit.

That is the frame a functional brand is actually pitching into. The buyer is not deciding between your item and nothing; they are deciding between your item and the door space currently held by something with a known non-promoted velocity. Which is why the third column of the second table above is the one that matters in a line review, and why a national growth rate is close to irrelevant in that room.

What a functional beverages read cannot tell you

Transactions record what sold, at what price, in what basket, at what time. They do not record whether a benefit was delivered, whether the shopper believed the claim, or anything about who the shopper was. This page makes no health claim about any functional beverage and no claim about consumer motivation, because point-of-sale data cannot support either and the vocabulary of this category makes the slip easy.

The defensible sentence is 'items carrying a prebiotic claim sold 1.24 units per item per store per week, 51% of them on promotion'. The indefensible one is 'shoppers are turning to gut health'. The first is what the data says. The second is a story about people written from a table about cans.

How Scout fits

Scout reads store-level POS and holds item attributes, price, promotion and placement in the same model, so the claim-tagged comparison above is a view rather than a project, and the non-promoted split is a default rather than a special analysis. In a category promoted this heavily, that split is the difference between knowing an item's base and guessing it.

The boundary worth stating: Scout's numbers are transactions. It does not run consumer research, it does not measure attitudes, and it makes no claim about health outcomes. Where a question genuinely needs a person rather than a receipt, it needs loyalty-linked data or a survey, and Scout will not be the source.

Related: beverage industry trends and functional ingredients.