Mycelium vs Fruiting Body: Which Makes the Best Mushroom Supplements?

Medicinal mushrooms have been used for centuries, but only recently has the conversation shifted to the mycelium vs fruiting body debate. While the fruiting body has traditionally been prized for its high concentration of beta-glucans and polysaccharides, some modern supplements now include mycelium on grain and mycelial biomass, claiming additional benefits.

It’s easy to see why mycelium was overlooked in the past—it grows mostly underground, out of sight, and intertwined with its growing medium. But today, thanks to modern cultivation, both mycelium and fruiting body extracts are readily available.

So, in the battle of mycelium vs fruiting body —which one truly offers superior benefits in mushroom supplements? Stick with us as we unpack the science behind these two fascinating fungal components and how they impact your health.

When we say “mushroom,” you probably immediately think of the cute little cap-and-stem creature that pops up on your lawn after a rain. While these are technically mushrooms, they aren’t the entire fungus–they aren’t even the majority of the fungus.

No, the “mushroom” is only the reproductive structure produced by the fungus, otherwise known as the “fruiting body.”

The vast majority of the fungus exists beneath the surface as a sprawling web of filaments, similar to the roots of a plant. This dense web, which serves as the vegetative body of the fungus, is called the “mycelium,” and it does nearly all the work to sustain the life of the fungal organism.

Before we can really break down the differences between fruiting body vs mycelium, we need to make an important point: Both parts of the fungus are crucial, of course, working harmoniously together to sustain the fungal life cycle. 

The mushroom life cycle, which relies equally on the fruiting body and the mycelium, goes a little something like this:

You probably know that mushrooms are good for you, but do you know why?

According to both anecdotal reports and modern research, medicinal mushrooms have a slew of potential health benefits. 

Some mushrooms, like Chaga, Turkey Tail, Reishi, Maitake, and Shiitake have been linked to immunomodulatory effects, meaning they may help to boost immune responses to keep us well and fight off common ailments. 

Some of these mushrooms and others, like Cordyceps and Lion’s Mane, have been classified as nootropics, or substances that boost cognitive function by impacting the way the body produces and uses certain neurotransmitters. Some medicinal mushrooms have even been linked to more specific therapeutic opportunities, like treating Alzheimer’s Disease or various types of cancer. 

How can these fantastic fungi do all of this? The answer lies in a few bioactive compounds that can be found in all mushrooms. The two most prominent and well-researched bioactive compounds found in mushrooms are:

• Beta-glucans, which are a form of dietary fiber known to have a positive effect on the digestive system and gut-brain axis. Various types of beta-glucans, which are primarily found in the cell walls of fungi and cereals (like oats and barley), have been linked to improved cognitive function. Beta-glucans may also support immunity and are considered to be both antibacterial and antiviral. 
• Triterpenoids, a compound responsible for the fungi’s adaptive capabilities, which are frequently described as “anti-inflammatory, antiviral, antimicrobial, and antitumoral agents, as well as being immunomodulatory compounds.”

So, if you want a mushroom supplement that carries all of the benefits associated with medicinal mushrooms, you want one that is full of these bioactive compounds. That’s where the mycelium vs fruiting body debate becomes very clear. Let’s look at the difference:

While the mycelium and the fruiting body are two parts of the same whole, they are very different. Specifically, the fruiting body of the fungus usually has a beta-glucan content of 30% or more. The mycelium, on the other hand, only has a beta-glucan content of around 5%, sometimes falling as low as zero.

Those numbers alone make it very clear cut – supplements made from fruiting bodies are higher quality with more bioactive, health-boosting compounds. But the differences don’t stop there. Mycelial products are also heavily degraded, containing a large amount of starch.

Why? Because mycelium, being the dense mass of filament that it is, is impossible to separate from its growing medium. In fact, during the mushroom growth cycle, it becomes so intertwined with the substrate that the two become nearly indistinguishable from each other. 

So, when mycelial products are made, the mycelium is “harvested” with the substrate–which is usually a grain like oats or rice–and the entire block of starchy mycelium is ground up together. 

Ultimately, even the triterpenoids and other beneficial compounds that may exist in the mycelium are also degraded by the starch, producing a final product that is seriously lacking bioactive compounds. 

Fruiting body supplements, however, are made from the reproductive part of the mushroom that grows out of the substrate. This cap and stem “mushroom” portion of the fungi are easy to harvest separately from the mycelium and grain material and can therefore be used to produce supplements that are much more pure and potent (in terms of beta-glucans and triterpenoids). 

With numbers this clear, you may be wondering why any companies even make mycelial products. What use do they even have? 

As it turns out, mycelium is extremely useful. It’s being used in all sorts of ways, from making biodegradable packing foam to producing vegan meat substitutes. It’s great for many things – just not for making wellness supplements, but that doesn’t stop supplement companies from producing myceliated products. 

Why?

In short, it’s because of greed. Thanks to the way that FDA guidelines are laid out, companies can exploit the ambiguity between “mycelium” and “mushrooms.” Products that contain fungi mycelium can legally be labeled as mushroom products so long as they specify that they are made with mycelium. Since many consumers don’t know the difference, it simply doesn’t matter. 

Plus, these regulations are not highly enforced and many manufacturers skirt these requirements without consequence. It’s entirely too true that mushroom products are misleading. In fact, one 2017 review found that of 19 reishi supplements purchased online, only five tested in accordance with their labels, meaning they contained some amount of reishi. 

Because consumers don’t understand the difference between mycelium and mushrooms and don’t know how to verify the quality of a mushroom product, companies can get by selling these poorly made, counterfeit products. And there’s plenty of incentive for companies to do this. 

For one, mycelium products are much cheaper and easier to produce. 

Think about it:

Mycelium forms early on in the mushroom growth cycle. Eventually, it will produce fruiting bodies in order to help the fungi reproduce, but what if manufacturers didn’t have to wait that long? What if mycelium could be harvested in mere days or weeks after introduction to the grain spawn? And what if half the weight of the final product was the grain itself?

Obviously, mycelium products are cheaper and faster to produce, which means that these companies can turn a bigger profit at the expense of their product quality. 

But these shady companies won’t tell you that, of course. In fact, they’ve come up with some pretty convincing marketing techniques to help sell their myceliated products. Let’s take a look at some of these false claims:

There are plenty of marketing ploys used to sell mycelium products, but, most often, you’ll come across two main statements:

This argument balances on the fact that the fruiting body could not exist without the mycelium–an argument that is based on truth and that appeals to proponents of “natural” medicines. 

It is, of course, true that mycelium is necessary for the production of fruiting body supplements. It is the life-giving structural body that helps to feed the fruiting bodies so that they can mature and do their important job of releasing spores to continue the fungal life cycle. 

However, the fruiting body, once mature, contains bioactive compounds that are independent of mycelium. The health benefits of these compounds are not at all reliant on the mycelium. While it is true that the mushroom mycelium may contain a diverse range of other bioactive compounds that may complement the effects of fruiting body compounds, they haven’t been found to be significant enough to counter the fact that mushroom mycelium always comes with a load of added starch and not very many of these bioactive compounds.

So, of course, another creative marketing ploy exists to justify the use of these starch additives:

This claim, which is the most common claim used to prop up the mycelium supplement market, originated with Paul Stamets, author of  “Mycelium Running: How Mushrooms Can Help Save the World” and owner of Fungi Perfecti LLC, a company that produces a variety of myceliated mushroom products. 

These products, most of which are not pure extracts, are made from mushroom mycelium that’s grown on a brown rice substrate. The products subsequently contain plenty of this rice material–but not as an additive, as a specific ingredient with its own proposed health benefits. 

According to Stamets, the fermented rice substrate is biologically active, offering a unique range of benefits that complement the mushroom-derived beta-glucans. In fact, Stamets claims that no mushroom compound is complete without mycelium and myceliated substrate. 

His claims balance one study that, despite its small sample size, included an open peer review process and has been reviewed by many experts in the field. In this research, the brown rice substrate was found to have substantial effects on immune function–another fact that may be true. However, the fermentation process, just like with yogurt or sauerkraut, generally produces bioactive probiotics. These compounds, while definitely beneficial, are hardly unique to mushrooms alone. 

Plus, the study has a few flaws, as some of the expert reviewers have pointed out. For one, the sample size was so small that it’s statistically irrelevant. Second, the two compounds being tested in this study–the mycelium and the substrate–were merely separated by scraping the mycelium from the substrate's surface. In other words, neither substance tested was “pure,” rather they were both contaminated with bits of the other substance, making it hard to get a clear picture of how the substrate acts on it's own.

Plus, while the research does compare the effects of the substrate to the effects of the mycelial material, there’s no comparison made to the effects of fruiting body supplements. Therefore, this is hardly an argument as to why mycelial products and the fermented grains on which they are grown are the superior supplemental form of fungi. 

If you look at the full picture, it’s obvious that fruiting body supplements are superior, albeit often more expensive and harder to find in the mycelium-flooded market. 

As an added assurance, consider that commercial mushroom farming is particularly new, and the harvesting and use of mycelium is a modern invention. Before modern farming techniques came into play (where mycelium is grown on controlled blocks of the substrate), the mycelium grew in tangled webs beneath the soil or inside the bark of trees. In other words, it couldn’t easily be harvested and was not the portion of the fungi body used in ancient medicinal practices. 

All historical data we have to back up the use of medicinal mushrooms–which far outweighs the amount of modern research that is available–specifically comes from the use of fruiting body mushrooms. So, to argue that mycelium supplements are better is to argue with both science and history. 

Even so, the market is flooded with mycelial products and mushroom supplements that are essentially just capsules full of grain and starch. How do you combat that as a health-conscious consumer that wants to get the most beta-glucan-bang for your buck? You have to read the label and know what to look for. 

Choosing a high-quality mushroom supplement is the most important factor in whether you will experience true benefits–and not all mushroom supplements are safely and responsibly made, regardless of which part of the mushroom they contain.  

If you want a mushroom product that’s biologically active, look for one made from fruiting bodies. Ideally, a great mushroom supplement should be made from 100% fruiting bodies. This should be clearly displayed on the label. 

And don’t stop there–the label should also display some sort of beta-glucan content. A good mushroom supplement should contain at least 20% beta-glucans or more. If the beta-glucan content is not displayed, it's likely that the product doesn't contain any. 

Here are some other things to consider:

• Whole mushroom or mushroom extract? Is the supplement made from whole, dried mushrooms that are ground into a powder, or is it a mushroom extract? Whole mushroom powder will contain all of the nutrients and fiber and bioactive compounds. An extract, however, will contain a concentrated version of the mushroom's bioactive beta-glucans, and is often the kind of formula chosen for medicinal use. 
• How is it made? Take a look at the entire manufacturing process. High-quality supplements should be made in a cGMP-compliant facility using FDA-approved ingredients. A great product will be made using organic and responsibly sourced ingredients.
• Is it lab tested? Like all supplements in the U.S., regulations are lower than what’s required for pharmaceuticals. So, it's up to you to check and make sure that products contain what they say they contain. For mushroom supplements, that means third-party lab tests that prove potency and purity. 

1. “The Monkey Head Mushroom and Memory Enhancement in Alzheimer’s Disease” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9331832/
2. “Current Uses of Mushrooms in Cancer Treatment and Their Anticancer Mechanisms” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9504980/
3. “Three Different Types of β-Glucans Enhance Cognition: The Role of the Gut-Brain Axis” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8927932/
4. “Effects of triterpenes on the immune system” https://pubmed.ncbi.nlm.nih.gov/20079412/
5. “Evaluation on quality consistency of Ganoderma lucidum dietary supplements collected in the United States” https://www.nature.com/articles/s41598-017-06336-3
6. “The mycelium of the Trametes versicolor (Turkey tail) mushroom and its fermented substrate each show potent and complementary immune activating properties in vitro” https://bmccomplementmedtherapies.biomedcentral.com/articles/10.1186/s12906-019-2681-7