Which is Best: Mycelium or Fruiting Bodies?

As interest in functional mushrooms continues to grow, so does the conversation around which part of the fungal organism offers the greatest benefits: the mushroom fruiting body or the mushroom mycelium? At Fungi Perfecti®, we’ve spent 40+ years cultivating mushrooms, conducting research, and exploring the remarkable potential of fungi. Through decades of hands-on experience, scientific investigation, and a growing body of peer-reviewed research, we’re convinced that mushroom mycelium is the most beneficial part of the mushroom lifecycle. 

That’s not to say mushroom fruiting bodies—the familiar caps and stems many recognize as mushrooms—aren’t valuable. Quite the opposite. Fruiting bodies have been used for thousands of years across cultures around the world and have played an important role in traditional wellness practices. We celebrate that history and the many ways USA-grown mushrooms continue to benefit people today. 

But we also believe the debate over whether mycelium or fruiting bodies are "better" misses a much larger story. 

The fruiting body visible above ground is only one stage in a much larger lifecycle. Beneath the surface lies mycelium: a vast network of microscopic threads that serve as the primary life stage of the fungal organism. While fruiting bodies have received most of the attention throughout history, advances in mycology are revealing that mushroom mycelium holds extraordinary, untapped potential of its own. 

At Fungi Perfecti, we’ve embarked on a journey of discovery that's gone beyond the benefits offered by fruiting bodies alone. We’ve journeyed past what we can see and ventured into a territory of enormous potential that lies unseen, just below the surface.

Is Mycelium Good for You?

Beneath the forest floor and woven throughout nearly every landscape lies mushroom mycelium. Often stretching for miles unseen beneath our feet, these vast networks of microscopic threads help support the health and resilience of the natural world. Mycelium forms critical relationships with plants, recycles nutrients, responds to environmental challenges, and helps sustain the ecosystems upon which all life depends.

For decades, scientists and mycologists have studied the remarkable role mushroom mycelium plays in nature. As the primary life stage of the fungal organism, mycelium serves as both a communication network and a protective system within its environment. In many ways, it’s the beating heart of every environment it calls home, acting as the immune system of the natural world.*

At Fungi Perfecti®, we strive to understand not just how the benefits of mycelium interact with the natural world, but importantly, how they can support human health. Just like humans, the environment has an immune system, and Fungi Perfecti has demonstrated through emerging science that mycelium can be the bridge that connects them.*

What Does Science Say About Mushroom Mycelium?

Our belief in the potential of mushroom mycelium is backed by a long-standing commitment to scientific discovery. Every year, we reinvest more than $1 million into scientific research, including research specifically examining the benefits of our Host Defense products. In partnership with the NIH, we published a trial examining the benefits of our Turkey Tail mushroom mycelium. We’ve also conducted much of our research in collaboration with leading institutions such as Bastyr University, the University of Minnesota, UC San Diego, and The George Washington University. *

Recently, we conducted a peer-reviewed, randomized, double-blind clinical study evaluating a combination of Turkey Tail and Agarikon mushroom mycelium in healthy adults. The study assessed safety, tolerability, and selected immune-related biomarkers. These findings contribute to the growing body of research exploring the role of functional mushrooms in supporting healthy immune function.*

When thinking about immune health, it’s important to understand that immune systems shouldn’t be “switched on” all the time. They should remain calm when threats are absent, but ready to act when they encounter challenges. We published a recent preclinical study demonstrating that extracts made from Lion’s Mane mushroom mycelium supported immune responses in vitro that remained calm and ready to act in the face of everyday challenges. Placed under the same challenging conditions, immune cells in vitro displayed a different result when exposed to an extract made entirely from imported Lion’s Mane fruiting bodies.

What Do the Experts Say About Mushroom Mycelium?

All the research we’ve done at Fungi Perfecti stems from the guidance and expertise of our founder, mycologist Paul Stamets, and our dedicated team of scientists. World-renowned for his discoveries about the power and potential of mushroom mycelium, Paul has paved the way for generations of new mycologists. He has authored eight books about fungi—including Mycelium Running—and has authored over 30 peer-reviewed scientific articles.

Through his work as a mycologist, Paul recognized that mushroom mycelium expresses 10 times more genes than those expressed by fruiting bodies. He also discovered that mycelium produces a wide array of bioactive compounds that can support human health. With his initial findings demonstrating that mushroom mycelium had the potential to aid both people and planet, Paul founded Fungi Perfecti to help fund these goals, which are part of Fungi Perfecti’s core values today.*

This research was so conclusive that Fungi Perfecti launched Host Defense® Mushrooms™, a supplement line designed to make it easy for people to experience the benefits of mushroom mycelium for themselves. Under Paul’s direction, Host Defense has focused on harnessing the unique benefits of mushroom mycelium and translating decades of mycological research into innovative mushroom supplements formulated to support human wellness.*

With every discovery he’s made, Paul has confirmed mushroom mycelium’s benefits to human health. Much like the character named after him on Star Trek: Discovery, Paul has led us all into a new frontier of fungal science, and there’s no going back.

What is the Best Way to Grow Mushroom Mycelium to Support Efficacy?*

Through Host Defense, we’ve discovered that mycelium grown on organic brown rice is the most bioavailable way to make our Host Defense mushroom supplements. To cultivate our mushroom mycelium, we use a process known as solid-state fermentation. During this process, the mycelium grows throughout organic brown rice, metabolizing and transforming it at both a chemical and physical level.

As the mushroom mycelium develops, it doesn't simply sit on top of the substrate—it actively consumes, alters, and integrates with it. Over time, the rice is transformed into a new, fermented matrix infused with fungal tissue and the diverse compounds produced by the mycelium during its growth.

A useful comparison is yogurt production. Just as beneficial bacteria transform ordinary milk into yogurt through fermentation, mushroom mycelium transforms the organic brown rice into something entirely new. The end result is not simply rice and mycelium existing side by side, but a fermented whole created through the natural metabolic activity of the fungal organism. 

Mycelial Biomass: How Does Solid-State Fermentation Aid Immune Health?*

Here’s where we discovered something remarkable: Mushroom mycelium transforms the rice, producing unique compounds that transform it to uniquely support immunological activity. This transformation process creates new bioactive compounds in the myceliated rice that are not present in plain, unfermented rice or pure mycelium.

Additional human cell model studies demonstrated that when the mushroom mycelium and the myceliated rice are together in one product, they work cooperatively to expand the spectrum of immune support beyond what either could provide alone! That’s why we use both the mycelium and the myceliated rice in all of our products—because they work.*

This transformative and cooperative process is one of the reasons we believe mushroom mycelium represents such an exciting frontier in fungal science. Solid-state fermentation allows us to harness the dynamic biology of the mushroom organism's primary life stage as it grows, adapts, and interacts with its environment.*

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.