The fruiting body is the mushroom you can see and pick: the cap, stem and gills. Mycelium is the hidden network of fine threads that grows through soil, wood or, in a factory, a tray of grain. Both are fungal tissue. They are not the same material, and a product made from one is not a product made from the other. For a mushroom tea, the sensible choice is a blend built on fruiting bodies, with the percentage stated plainly on the pack.
Below, we explain what each part is, what research does and does not show, how to read labels such as “100% fruiting body” or a percentage figure, and how we approach it at MycoBrew.
TL;DR
- The fruiting body is the reproductive stage of a fungus. Mycelium is its vegetative, mostly hidden stage. Their differences come from which genes are switched on, not from different genomes.
- Studies find the two can differ in their compounds, and the pattern varies by species, strain and how the fungus was grown. Neither is proven “better” in every case.
- Human evidence for functional mushroom benefits is limited for both forms. Treat any bold health claim with caution.
- On a label, look for the part of the mushroom used, the percentage, and whether grain is included in the weight.
- Our teas use 40% fruiting body mushrooms, are caffeine-free and are lab-tested.
Table of Contents
- What a fruiting body and mycelium actually are
- What studies say about the differences
- What the evidence says about benefits
- What “100% fruiting body” and a fruiting body percentage mean
- Is eating mycelium good for you?
- Which is better, then?
- Our view at MycoBrew
- Choosing a mushroom tea by what you want from the cup
- Try a fruiting body tea
- A quick checklist for reading any mushroom product
- FAQ
- Sources
What a fruiting body and mycelium actually are
A fungus spends most of its life as mycelium. This is a web of thread-like cells that spreads through its growing medium, absorbing nutrients. When conditions are right, the mycelium builds a fruiting body above ground to release spores. That is the shiitake in a stir-fry, the lion’s mane with its shaggy white spines, the reishi with its glossy bracket.
A 2022 academic comparison of edible fungi describes mycelium as the often-hidden vegetative form and the fruiting body as the reproductive stage. It also notes that their visible differences result from differential gene expression rather than changes to the genome. In other words, it is one organism running two different programmes.
That matters for what ends up in your cup. Because the programmes differ, the chemistry can differ too.
Where each one comes from in a product
Fruiting bodies are grown to maturity, harvested, dried and then milled or extracted. This takes time and space, and it is why they cost more to source.
Mycelium is often grown in a bioreactor or, more commonly in supplements, on a solid substrate such as rice or oats. Once the grain is colonised, the whole lot may be dried and ground. That is where the labelling questions begin, because what you buy can be a mix of fungal tissue and the grain it grew on. We come back to this below.
What studies say about the differences
The most useful single source here is the 2022 review by Berger and colleagues, which compared mycelium and fruiting bodies of edible fungi directly. Its findings are more nuanced than the usual online debate suggests.
- Compounds vary by species, strain and growing conditions. In that review, fruiting bodies of Agaricus bisporus contained more ergothioneine, while mycelium of Lentinula edodes (shiitake) released more lovastatin into digestive juices. Neither result makes one form the universal winner.
- Protein is similar. Direct comparisons found similar protein concentrations in fruiting bodies and mycelia, while other metabolites depended on the substrate, the strain and the developmental stage.
- Fruiting bodies tend to be richer in some compound groups. The review reports that fruiting bodies contained high concentrations of phenolic and indole compounds. A separate 2021 review of medicinal mushrooms says bioactive metabolites occur in mycelium and, above all, in fruiting bodies, with the distribution depending on the species.
So the fair summary is this: fruiting bodies are the better-studied and more traditional material, and they are generally where researchers find the richest range of the compounds people talk about. Mycelium is not worthless. Berger et al. conclude that fungal biomass produced under food-grade conditions at industrial scale could be a safe, nutritious food ingredient. But “nutritious ingredient” is a different claim from “delivers the same compounds as the mushroom”.
A note on beta-glucans
Beta-glucans are the compounds most often cited in this debate. Because they sit in the cell walls of fungi, they are present in both forms. The practical problem is measurement. Starch from grain can show up in some broad tests for polysaccharides, which is why a headline “polysaccharide” figure can say little about beta-glucan content. If a brand quotes numbers, ask what was actually measured and how.
What the evidence says about benefits
This is where honesty matters most, so here is the plain position.
The 2021 medicinal mushroom review lists reported activities including antimicrobial, anti-inflammatory, immunomodulatory, antioxidant and prebiotic effects. It also states that most research is in vitro or preclinical, with only a small number of human clinical studies available.
Which? reported that most functional mushroom research is in vitro or in animals, that the human studies are generally small, and that Great Britain’s Nutrition and Health Claims Register had no approved health claims for mushrooms. The Guardian made a similar point: levels of potentially active compounds vary with species, cultivation and whether an extract comes from fruiting bodies or mycelium, and doses in many products are hard to establish.
Lion’s mane as an example
Lion’s mane is the species most often linked with focus, so it is worth looking at what the research actually holds. A 2025 systematic review of Hericium erinaceus included five randomised controlled trials, three pilot clinical trials and mainly laboratory studies. It found some improvement in cognitive symptoms, but said the evidence was limited by small samples, short durations and very different preparations. Those preparations include both fruiting body and mycelial material, which is part of why the results are hard to compare.
Reishi and the gut
A 2024 review of Ganoderma lucidum says potentially active compounds occur at both the fruiting-body and mycelial stages and may affect gut flora. It treats this as an area of research, not as established benefit for consumers.
Cancer claims
If you or someone close to you is dealing with cancer, speak to your oncology team before taking any mushroom product. Cancer Research UK says there is not enough evidence that any mushroom can prevent or cure cancer. Early work suggests possible effects on the immune system, which is not the same as treatment.
Supplements are not medicines
Guy’s and St Thomas’ NHS Foundation Trust states that mushroom products are dietary supplements with limited evidence of effectiveness, that their effects cannot always be predicted, and that they are not necessarily regulated like medicines. If you take regular medication, are pregnant or breastfeeding, or have a health condition, ask your GP or pharmacist before adding a new supplement.
What “100% fruiting body” and a fruiting body percentage mean
These are the labelling questions readers search for most, and the answers are simple once you know the terms.
“100% fruiting body” means the product is made from the fruiting body of the mushroom and not from mycelium grown on grain. Some brands describe a “full spectrum” product, which can include substrate, mycelium, primordia (the baby mushroom stage) and fruiting body together.
A fruiting body percentage tells you how much of the product, by weight, is fruiting body. This is the figure to compare. In UK food labelling, a quantitative ingredient declaration (QUID) gives the percentage of particular ingredients. Government guidance says it is required when an ingredient is named in the food’s name, emphasised on the label, characterises the food, or is usually associated with that name. A tea sold as a mushroom tea falls squarely in that territory, so a percentage is something you should expect to see.
Why the percentage is not the whole story
A percentage describes the share of the blend, so it depends on what the rest is. In a tea, the remainder should be botanicals chosen for flavour. In a product built on myceliated grain, the remainder can be the grain itself. That is why we suggest you check four things on any pack:
- Which part of the mushroom is used. “Mushroom powder” or “mycelium” with no mention of fruiting body should prompt a question.
- The percentage, and what it refers to. The whole blend, or the mushroom ingredient only?
- What else is in it. Grain, fillers, flavourings, added caffeine.
- Whether testing is available. A certificate of analysis from an independent lab is a better sign than marketing language.
Extract ratios add a further layer for powders and capsules. A 16:1 ratio, for instance, means 16 kg of raw fruiting body went into 1 kg of extract. That is a different product from a tea made with dried fruiting body, so the numbers are not directly comparable.
Is eating mycelium good for you?
Probably harmless in food-grade form, but that is not the same as beneficial in the way the label may imply. The Berger review supports mycelium as a safe and nutritious food ingredient when produced under food-grade conditions. Mycelium-based foods are also being assessed as novel foods in the UK: the Food Standards Agency and Food Standards Scotland assessed pea protein fermented by shiitake mycelia for safety and nutritional disadvantage. That assessment looked at safety, not health benefits or claims.
The real concern with mycelium supplements is not toxicity. It is what you are paying for. When a product is mycelium grown on rice or oats, part of the weight is grain, and the amount of the fungal compounds you want may be small. This is a labelling and value question rather than a safety one.
Which is better, then?
Here is the honest answer in three parts.
- For a food or tea, fruiting body is the more sensible base. It is the part people have eaten for centuries, it is the part most compound research focuses on, and it is clear what you are getting.
- Mycelium has a place, but it should be described honestly. If a product contains it, the label should say so, and it should not borrow the reputation of the fruiting body.
- Neither guarantees a health outcome. Given the state of human evidence, the best reasons to drink a mushroom tea are taste, ritual and a caffeine-free alternative, with any wellbeing benefit as a bonus rather than a promise.
If you are curious how mushroom ingredients show up in other formats, mushroom coffee versus energy bars looks at ritual versus fuel, which is a useful way to think about why format matters as much as the mushroom.
Our view at MycoBrew
We built MycoBrew around one decision: use fruiting bodies, and say how much. Every blend contains 40% fruiting body mushrooms, alongside botanicals chosen so the cup tastes good rather than earthy or gritty. Our blends are naturally caffeine-free, organic, crafted in the UK, lab-tested, and packed in biodegradable pyramid tea bags.
We choose the species for what they are known for in traditional use and current research interest: Lion’s Mane, Reishi, Shiitake, Maitake and Agaricus. We are careful not to promise medical outcomes. The research on functional mushrooms is still developing, and a tea is a food, not a treatment. What we can stand behind is the sourcing, the stated percentage, the testing and the experience of sitting down with a proper cup.
Our advice is the same as what we do: pick products that tell you which part of the mushroom is inside, give you a percentage, and are happy to show their testing. If a brand cannot answer those three things, keep looking.
— Leroy
Choosing a mushroom tea by what you want from the cup
Flavour and routine usually decide whether a tea becomes a habit, so start there. Here is how our range lines up.
| Blend | Mushroom | Typically chosen for |
|---|---|---|
| Lion’s Mane | Lion’s Mane | A smooth daytime cup in place of coffee |
| Reishi | Reishi | An evening wind-down |
| Agaricus | Agaricus blazei | A daily routine with an immunity focus |
| Shiitake | Shiitake | Everyday wellness drinking |
| Maitake | Maitake | Balance and everyday wellbeing |
The focus, relaxation and immunity labels describe how the blends are positioned and traditionally used, not clinical results. If you want a gentle introduction, our beginner’s guide to functional mushroom tea walks through the species and how to brew them.
Try a fruiting body tea
If you would like to taste the difference a high fruiting body content makes, browse the full MycoBrew range. You can order once or subscribe for recurring delivery at a discount. Each blend is 40% fruiting body mushrooms, caffeine-free and lab-tested, so you know what is in the cup.
A quick checklist for reading any mushroom product
Before you buy, run through these questions. They take a minute and they cut through most of the marketing.
- Does the label say fruiting body, mycelium, or both?
- Is there a percentage, and is it clear what it measures?
- Is grain or another filler listed in the ingredients?
- Is there a certificate of analysis or other independent testing?
- Are the claims modest, or does the pack promise to prevent or treat illness? In the UK, no health claims for mushrooms are currently on the approved register, so bold claims deserve scepticism.
- Does the format suit you? A tea you enjoy and drink daily will do more for your routine than a capsule you forget.
FAQ
Which is better, fruiting body or mycelium?
For teas and foods, fruiting body is the more dependable choice, because it is the part most research examines and it is clear what you are buying. Studies show the two forms can differ in their compounds, and the pattern depends on species, strain and growing conditions. Neither form has proven health benefits in people on the evidence available today.
What does 100% fruiting body mean?
It means the product is made only from the fruiting body of the mushroom, not from mycelium grown on grain. Products described as full spectrum or myceliated grain can contain grain substrate and mycelium as well. Check the ingredients list and ask for testing if it is not shown.
What does a fruiting body percentage mean?
It is the share of the product, by weight, that is fruiting body. In UK labelling, a percentage is expected when an ingredient is named in the product’s name or emphasised on the pack. Look at what makes up the rest of the blend, as that tells you whether you are paying for mushroom, botanicals or filler.
Is eating mycelium good for you?
Food-grade mycelium can be a safe and nutritious ingredient, according to a 2022 academic review. That does not mean it delivers the same compounds as the fruiting body, and mycelium grown on grain may be partly starch. If you are unsure, speak to your GP or pharmacist, especially if you take medication.
Sources
- Mycelium vs. Fruiting Bodies of Edible Fungi: A Comparison (2022)
- Medicinal Mushrooms: Bioactive Compounds, Use, and Clinical Trials (2021)
- Which?: What are functional mushrooms and do they have health benefits
- The Guardian: Functional fungi and medicinal mushrooms
- Systematic review of Hericium erinaceus (2025)
- Regulatory effect of Ganoderma lucidum (Frontiers, 2024)
- Cancer Research UK: Mushrooms
- Guy’s and St Thomas’ NHS: Herbal remedies and dietary supplements
- GOV.UK: Food labelling, giving food information to consumers
- FSA and FSS: Safety assessment of pea protein fermented by shiitake mycelia
- Mushroom coffee versus energy bars
