The Truth About Mushroom Supplements (From Someone Who Gives a Damn)

There has been a lot of interest in mushroom supplements in the past five years—more interest in fungi overall. It's been coined the "Shroom Boom" or "Mycorevolution."

I want to elucidate the fact that we don't know enough about mushrooms to be certain exactly what dosage is "right." There is a lot of product variation in bioactive compounds based on genotypes (strains), part of the fungus used, whether it's an extract, where it's grown, and more.

Language Shapes How We Understand the Fungal World

To start, I want to share that words are how we communicate ideas to others. By defining parts of animals, plants, fungi, or the rest of the natural world around us, we can pass along knowledge and information. Defining a word one way or another is just our best attempt to communicate.

Coming to a consensus on how we describe something helps make learning easier and allows us to research things more deeply. So when you're reading this, please remember that the parts of the mushroom that are so heavily marketed might be one person's way of sharing their knowledge—but it might not be the best. Use your brain and think before you buy.

Mushroom supplement products are still supplements. There is nothing greater than eating whole foods and incorporating mushrooms into your regular diet. But if you want to take mushroom supplements, this is what to consider and what to know about products in the marketplace.

Every Species Is Different—There Are No Blanket Rules

"It depends." This is something I say over and over again. Each species is unique and different. Making blanket statements about what part of the mushroom to take is nonsense because it depends on what species you're interested in. Some compounds are only produced in the mycelial growth form, while others are created over extended periods of time in the fruiting bodies of the fungus.

Most mushroom products are not tested for bioactive compounds, and what's on the label can sometimes be misleading.

The Internet Is Full of Garbage—And AI Isn't Helping

Now, more than ever before, information online is bloated and filled with AI-generated content. You'll see a lot of people talking about one thing or another like they're an expert, when we truly don't know enough. That's why testing and transparency are so important.

Don't fall into the trap of thinking AI has the right answers either. It simply pulls from what's on the internet and parrots it back without knowing what's right or wrong—just what's most prevalent.

Beta-Glucans Are Not a Marker of Quality

Beta-glucans should not be trusted as a reliable indicator of product quality. There—I said it. They're not. They can even be used as filler in products, especially those sourced from East Asia, specifically China.

The fact of the matter is that in Chinese business culture, it's often accepted to mislead or exploit Western buyers. This should be taken seriously when sourcing materials overseas. Always verify everything yourself with in-house and third-party testing.

Don't trust anyone when you're sourcing—regardless of who or where they are—until a long-term, proven relationship is established.

The FDA Barely Requires Testing—And That’s a Problem

Currently, the FDA only requires identity testing once per year. Yes, ONCE per year. That means you can get a clean first batch from a supplier, verify the species and composition, and then receive filler-laden batches for the rest of the year without knowing—unless you test again.

Worse, what part of the batch you test also matters. If you test the top of the barrel or bag, they may have placed the authentic material on top with filler below. You wouldn't know unless you tested the middle and bottom too.

Homogenized mixing of materials is not standard and must be verified. You need to sample from the top, middle, and bottom of each barrel in each shipment. Then test for:

• Product identity

• Purity

• Potency

• Heavy metals

• Pesticides

• Residual solvents

• Aflatoxins

• Microbial loads (Salmonella, E. coli, total coliforms, yeasts, molds, aerobic bacteria, Listeria, Staphylococcus, and Enterobacteriaceae)

  
  

Sounds like a lot of testing, right? So if a supplier says they’ve done it, it must mean it’s a quality product? Not exactly. This is just the bare minimum for selling safe products in the U.S., Canada, and Europe.

Testing for heavy metals, pesticides, aflatoxins, and residual solvents is only required once per year for supplier qualification—not for every batch.

I'll say it again: you need to test for everything until you know for sure that your supplier consistently delivers high-quality products.

One major issue the industry faces is that we don’t have standardized testing protocols for mushroom products. Depending on the lab and the method used—whether it’s HPLC (High-Performance Liquid Chromatography), HPTLC (High-Performance Thin-Layer Chromatography), NMR (Nuclear Magnetic Resonance), or GC-MS (Gas Chromatography-Mass Spectrometry)—you can get wildly different results.

Why? Because not all mushroom products are the same. Mycelium-based products, fruiting bodies, full-spectrum blends, powders, and extracts all have different chemical compositions and solubility characteristics. And what works to test one product type doesn’t work well for others.

Without validated, product-specific testing protocols, numbers on a Certificate of Analysis mean very little.

This is why organizations like AOAC and USP need to co-develop and validate standards tailored to the nuances of mushroom-based supplements. Otherwise, companies will continue to cherry-pick results from labs that happen to show what they want.

Marketing ≠ Transparency

What does this mean for consumers? Think critically. If it seems too good to be true, or the label makes bold claims like “lab verified,” ask yourself:

Is this just marketing?

Because it's easy to fall into that trap and say, "Yeah, they seem trustworthy because they test their product." No. Testing is the bare minimum to ensure the product is safe to consume.

What Should You Look For on Labels?

A lot of websites and influencers will tell you things like "Only consume 100% fruiting bodies" or "Avoid products with fillers like grains and starches."

But those aren't universal rules. Like I said—it depends. There are no blanket statements to be made about mushrooms. We simply don’t know enough.

Finding the right product requires work. Not all species provide the benefits you want. Each species has different cultivars or genotypes. Plus:

• What it grows on

• How long it’s grown

• What part is harvested

...all affect the quality.

To quote a beloved fast food chain: "It’s quality you can taste." That doesn’t mean it’s good or bad quality—just that there’s a quality being delivered.

So Let’s Talk Extracts

They sound great: higher potency, extract the bioactive compounds, no fillers. But that doesn’t necessarily mean any of those things.

10:1 extracts, 4:1, 2:1, 1:1—what do they actually mean? A 10:1 extract means you take 10g of raw material and are left with 1g of finished product. Sounds potent, right? But most mushrooms are 90% water, so if you simply dry fresh mushrooms, you already have something that’s 10:1.

Generally, higher quality products are 4:1 or 2:1, but it also depends on the type of extraction.

When you extract something, you’re inherently separating out parts of the raw material. But what can guarantee that the bioactive compounds were extracted—or that they weren’t stripped away in the process?

Dual extractions sound fancy because two solvents are used. Triple extractions sound even better because that’s what people historically did for thousands of years.

This is one of those historical practices that sounds great in marketing, but may not reflect optimal preservation of bioactive compounds.

Dual extraction generally means both water and ethanol are used, which pulls out both water-soluble and fat-soluble compounds. Heating or not heating the extract also impacts potency. For example, low-temperature extracts (below 200°F) can release more bioactive compounds like erinacines from Lion’s Mane—but that has to be a mycelium-based product to begin with.

Erinacines are also a class of diterpenes, which are fat-soluble and not extractable through water alone. Only a few erinacines have been found to cross the blood-brain barrier, which makes them incredibly unique—and incredibly misunderstood in many formulations.

Triple extraction was historically done with roots and barks to make them safe to consume. The process involved boiling down the raw material three times to sterilize it. But this doesn’t mean it’s more concentrated—it often means bioactive compounds were volatilized or degraded.

Dual extraction is what you should look for in extracted products, especially in liquid form.

Some extracts are spray-dried. This means they take the raw materials, soak them in water, add enzymes and other agents, centrifuge it to remove solids, add a carrier like maltodextrin, then spray it through a high-pressure atomizer at 450°F to turn it into powder.

Sounds intense, right?

So what’s happening to the bioactive compounds at those temps? Isn’t maltodextrin just starch filler? And what about the fat-soluble compounds that aren’t water-extracted?

This is why testing is important.

But contrary to popular belief, maltodextrin can actually be a good thing. It protects the product at high temperatures. It’s a carrier. But remember: only water-soluble compounds are extracted this way—like certain polysaccharides.

The polysaccharides people talk about most are high molecular weight ones that are immunomodulating and support digestion, bloating, and other GI issues. Some do much more. For example, proteoglucan (found in Maitake – Grifola frondosa) and lentinan (found in Shiitake – Lentinula edodes).

There’s a great product out there called Maitake Gold, a fruiting body extract also known as D-Fraction. That’s something to look for.

People often talk about grain in mushroom products like it’s a dirty word. But growing on grain isn’t inherently bad—it can actually make products safer and easier to work with. Mycelium secretes secondary metabolites into the substrate, so you're still capturing bioactive compounds, just with less potency per gram than pure mycelium.

Liquid cultures are probably the king of the mycelium world—cleaner, more controlled, and substrate-free—but expensive and rarely used at scale.

The real issue isn’t the grain—it’s transparency. Is the brand being honest about what part of the fungus is used? Are they testing for actives? Are they using grain just to cut corners, or as part of a thoughtful cultivation method?

Functional Mushrooms—A Few Worth Talking About

There are a few species I think are worth calling out—not as a ranked list or hierarchy, but because they illustrate how nuanced this space is.

Lion’s Mane (Hericium erinaceus) is one of those. I personally would only take mycelium-based products here. Erinacines—compounds shown to promote nerve growth factor—are found in the mycelium, not the fruiting body. Hericenones from the fruiting body exist too, but they’re weaker in terms of bioactivity and don't cross the blood-brain barrier the way certain erinacines can. Plus, Lion’s Mane fruiting bodies are short-lived and mostly water—so what exactly are you concentrating in an extract?

Then there’s Reishi (Ganoderma lingzhi), a classic. This one develops woody fruiting bodies rich in triterpenes like ganoderenic acids and ganoderic acids, which are well studied. Dual extractions—particularly in liquid form—can work well for Reishi. Historically, people have even consumed just the spores, which adds another layer to the puzzle. And there’s ongoing conversation among growers and researchers about whether other Ganoderma species might outperform lingzhi. That's a whole other rabbit hole.

Cordyceps militaris gets the pop culture spotlight, partly thanks to "The Last of Us." It’s rich in cordycepin, adenosines, and mannitol (sometimes referred to as cordycepic acid). The strain CS-4 is common in commercial cultivation, but that doesn't make it the best. Cordycepin is water-soluble, so you don’t necessarily need a dual extract. Keep an eye on the grow method and whether the brand is using unique genotypes.

Turkey Tail (Trametes versicolor) has been studied since the 1950s for immune benefits. Polysaccharide-K (PSK) and polysaccharide-peptide (PSP) are found in the mycelium and fruiting body—because yes, mushrooms are basically tightly woven mycelium. The mycelial products can be just as effective, depending on what you're looking for.

And Chaga (Inonotus obliquus)—well, this one's complex. What people typically use is the sclerotium, not the true fruiting body. Wild-crafted Chaga from birch trees is often praised for containing betulinic acid, but that compound comes from the birch itself. You could just use birch bark. That said, wildcrafting raises real ethical concerns. Chaga takes years to form and grows almost exclusively on birch trees in cold forests. Overharvesting and irresponsible foraging practices are already impacting forest ecosystems. We need to start asking ethical questions about where our Chaga is coming from, how much is being taken, and whether that harvesting is reciprocal and sustainable. Also, Chaga produces oxalic acid, which in high or regular doses can damage the liver and kidneys. If you're going to use it, ask the supplier how it’s grown or harvested, and avoid brands that don’t understand the difference between mycelium and sclerotium.

Milligrams per dose matters. 500mg of 10 species = 50mg each—not enough.

Aim for 400–1000mg per species daily. Start small, increase with experience. Always talk to your doctor first.

How to Vet a Brand Mini-Checklist (and Suppliers)

Questions to Ask a Mushroom Brand:

• Can they provide a full Certificate of Analysis (CoA) for each batch?

• Do they test for product identity for every batch?

• Do they test for heavy metals, aflatoxins, residual solvents—on every lot?

• Do they list the extraction method and part of the fungus used?

• Can they trace the product back to the grower and substrate?

• Are they using validated lab methods or just “beta-glucan” buzzwords?

• Is the brand talking about regenerative practices?

• Are they sourcing wild mushrooms responsibly?

• Do they grow on synthetic substrates with high energy inputs?

The Bottom Line

Let’s be honest—just because a product says it's lab-tested, or lists fancy extraction ratios, doesn't mean it's high quality. A lot of what’s out there is just marketing dressed up as science.

If reading this article made you more confused—welcome to the conversation. That’s the point. The mushroom supplement space is complex, unregulated, and filled with gray areas. We just don’t know enough to say one product is always better than another. That’s why gimmicky claims like:

• “10,000mg per dose!”

• “10:1 extract!”

• “30% beta-glucans!”

• “3rd party tested!”

…don’t mean much unless we know what was tested, how, and why.

It depends. It's not just whole mushrooms vs mycelium. It depends on each species independently from one another. Each part of the fungus has benefits, who or what they benefit is another topic entirely.

Start asking yourself:

What kind of supplement industry do we want to build—one built on marketing, or one built on evidence?

How do we respect the intelligence of the consumer, the complexity of fungi, and the future of wellness—at the same time?

Join the Movement

We need proper testing for bioactives. If you're a consumer, formulator, or big brand, advocate for better standards.

At Spore Growth Partners, we make our better future. Let’s raise the bar—together. If you’re a grower, formulator, researcher, or someone who gives a damn about the future of functional mushrooms—reach out.

Let’s stop selling magic and start building science.

—Spore Growth Partners