The category is not cooling off

Google Trends measures how a search term's popularity moves over time, worldwide, indexed to its own peak. It cannot tell you sales, but it is the closest thing to a live read on genuine curiosity, and it cannot be bought or gamed by a brand's marketing budget. Here is where nine functional mushroom terms stood in 2018 against where they stand now.

Every single one of these nine terms moved up over the period. Not one went down, and chaga, already a well-known search term back in 2018, still grew from a much higher starting point than the others.

The science did not stay still either

Search interest can be a mood. Peer-reviewed publishing is slower to move and much harder to fake. We counted every paper on PubMed with each species' scientific name in the title or abstract, by year, from 2015 to 2025.

Growth in peer-reviewed papers published, 2015 to 2025. We are showing growth rate rather than raw totals here because the starting points are wildly different, Reishi had four times as many papers as Chaga back in 2015, so a straight side-by-side of totals would flatter the mushrooms that already had a head start. Raw counts below, so you can check our math.

Seven firms priced this category. They disagree by three and a half times.

The paid market reports all sell the same promise: the real size of the functional mushroom category, in dollars. They cost a few thousand euros each. We are not going to buy seven of them, and neither are you, but every one of these firms publishes its headline number for free on its own marketing page to advertise the report. So we collected them and put them side by side, which is the one thing none of them do.

Here is what each firm says the global functional mushroom market was worth in 2025.

Global functional mushroom market, 2025, as published by each firm. Two more firms are in our source list but are not plotted here because they do not state a 2025 figure: Business Research Insights starts at $47.1B in 2026, and Technavio publishes only growth, not a base size.

The gap is not a rounding error. It is a definition. The firms at the bottom count supplements, extracts and powders. The firms at the top also count mushroom coffee, functional drinks, cosmetics and pharmaceutical applications. Same category name, two different questions, roughly a 3x difference in the answer. Nobody is lying. They are measuring different things, and a headline number quoted without its definition is close to meaningless.

So we would not trust any single number on that chart, and we would not trust an average of them either, because averaging two definitions gives you a figure that describes nothing real. If you need one number to hold on to, use the cluster that matches your question: roughly $12B for supplements and extracts, or roughly $36B if you count everything with a mushroom in it.

What they do agree on

Here is the part we found genuinely interesting. The firms cannot agree within 3x on how big the category is today, but they land remarkably close on how fast it is growing. Eight forecasts, seven of them inside a three point range.

That agreement is worth more than the size estimates, and there is a reason for it. A growth rate is far less sensitive to where you draw the category's boundary than a dollar total is: whether or not you count mushroom lattes, the whole thing is compounding at about the same clip. Independent firms, incompatible definitions, and the growth curve still comes out the same shape.

Worth holding next to Signal 1. Worldwide search interest in these terms has grown many times over since 2018, while the money is forecast to compound at about 9% a year. Curiosity is running well ahead of the spending. Those are two different things, and anyone selling you the search-trend chart as if it were a sales chart is skipping that step.

The EU Novel Food status of functional mushrooms, in plain English

We learned this one the hard way. Turkey Tail is classified as a novel food in the EU, which caused a payments provider to flag our store and forced us to reformulate a product line in 2026. The European Commission's own Novel Food status catalogue is accurate, but it is split across a searchable database, a consultation table, and a PDF regulation, and it is written for regulatory affairs teams, not for a small producer trying to figure out what they can legally sell. So we pulled together the plain-English version.

The short version: if you are selling a fruiting-body extract of Lion's Mane, Reishi, Maitake, Shiitake or Chaga in the EU, you are almost certainly fine. The moment mycelium powder or Turkey Tail enters the formula, get a straight answer before you launch, not after.