Bestseller

Organic Reishi

  • Immunity
  • Nervous System Support

4.8 (103 customer reviews)

Robust everyday defences. Supports your immune response over time, settles the nervous system daily.

30 capsules · 30 days supply

Temporarily unavailable

We test against the registered reference sample of Reishi. The current batch came back with less than 90% consistency with that reference, so Reishi is off sale while we find out why.

  • Delivery on us
  • 60-day guarantee

Nothing for the first fortnight and I nearly cancelled. Week three I started sleeping through. Give it a few weeks before you make your mind up.

Gary M Reviewed Feb 2026

A capsule after dinner I can manage… Three months in, I’m calmer in the evenings and I sleep more soundly, and on the rare night I forget I do notice.

Sally-Anne B Reviewed Jul 2026

Falling asleep was never my problem. Staying asleep was… I still wake some nights but I go back off, which is the bit that’s new. Feeling much more human at work.

Vanessa L Reviewed Feb 2026

I run a little shop and spend most evenings worrying about it. Less of that since I started the Reishi.

Euan Reviewed Apr 2026

Independently certified

Soil Association Organic
B-Corp pending
Third-party lab tested

Ingredients Full product spec

  • ReishiOrganic · 16:1 extract
  • >1.75%Ganoderic acids
  • >15%Beta-D-glucans

About Reishi

200 triterpenoids, 2000 years of medicinal use: Reishi's influence on vital biological systems earned it the moniker “Mushroom of Immortality”. We extract it at an industry-leading 16:1 concentration for peak efficacy.

Reishi Extract Benefits

  • Immune Support

    Triterpenes and beta-glucans activate natural killer cells and macrophages, enhancing your immune system's surveillance and response capabilities. Clinical studies show improved lymphocyte counts and immune cell activity.

  • Stress Resilience

    Ganoderic acids stimulate GABA receptors and regulate cortisol response, helping your body adapt to both acute and chronic stress. Supports your natural capacity for homeostasis under pressure. 

  • Cellular Protection

    Ganoderic acids increase production of superoxide dismutase and glutathione - your body's primary antioxidant enzymes - protecting liver, heart and brain cells from oxidative damage.

  • Cardiovascular Support

    Ganoderic acids act as natural ACE inhibitors, helping regulate blood pressure and vascular tone. These same triterpenes help modulate cholesterol levels by regulating HMG-CoA reductase activity.

  • Sleep & Recovery

    Triterpenoids enhance GABA signalling in the brain, promoting deeper sleep architecture and natural circadian rhythm regulation without sedation or grogginess We supply the most powerful, highly concentrated extracts on the market. Each capsule serving contains an industry-leading 7,200mg of Red Reishi (at 16:1 extraction ratio), with a minimum of 4% triterpene content. The Functional Mushroom Company is committed to unparalleled standards—delivering scientifically substantiated, potent mushroom supplements. Each product is rigorously researched and ethically sourced, embodying our dedication to purity and efficacy for individuals who prioritise integral health and genuine quality

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Ingredients and full panel

Independent testing

Third-party lab reports.

Our extracts are tested by an independent laboratory for heavy metals, pesticides, microbes and solvents. The full report and our organic certificate are below.

Batch dossier

Latest results

01 · Purity

Contaminant panels

Heavy metals
Clean
Pesticides
Clean
Microbials
Clean
Solvents
Trace remnants

Note: these contaminant results are from a combined sample.

Full test results PDF · 4.5 MB · Batch 26060025 Opens in a new window Latest organic certificatePDF · 230 KB · Licence DA31648 Opens in a new window

02 · Commitment

We're confident these are the highest quality mushroom extracts available anywhere in Europe. If you find a more potent product, we'll refund every order you've ever placed with us.

Every order · no time limitHow it works

Carbon-neutral shipping Method

Us versus them

Why we’re different.

This is a hard product to make properly — months of cultivation, then extraction that takes real expertise — and a very easy one to fake: gummies, tinctures, ten-species blends at doses too small to matter. In one study, 74% of mushroom supplements didn't contain what the label claimed.

We publish the things that can be checked: what's in the capsule, who measured it, and what they found. Five of them are listed here. Run the same five on anyone else.

Bioactives
Measured Beta-glucans only
Ganoderic acids (immunity and sleep) measured every batch

Tested for beta-glucans — also found in porridge

Authenticity
Fingerprinted Mislabelled
NMR-verified every batch — what's on the label is in the bottle

74% didn't match the label in one published test¹

Format
Capsules in glass Format varies
A fixed dose in capsules, in amber glass

Gummies, tinctures, loose powder

Dose
Meaningful dose Undisclosed
Therapeutic doses, disclosed in full

Weak doses in kitchen-sink blends

Contaminants
Four panels None published
Heavy metals, pesticides, microbials, solvents

Supplier paperwork (i.e. take their word for it), or nothing published

¹ Wu D. et al., Scientific Reports, 2017.

How to read a label

7 signs of a high quality mushroom extract

Mushroom supplements vary in quality more than almost any other category. Unlike creatine or magnesium — simple compounds, easy to standardise — mushrooms contain hundreds of bioactive compounds that demand the right growing conditions, careful extraction, and independent verification for each species.

Here's what to look for

Bioactive compounds

Know what you're buying

Look for species-specific markers: hericenones in Lion's Mane, ganoderic acids in Reishi, cordycepin in Cordyceps. These are what you're paying for. If a label doesn't specify, the product probably doesn't contain meaningful amounts.

See the ganoderic acids row

Species verification

DNA and NMR testing

A 2017 study of 19 commercial reishi products found 74% did not contain what the label claimed.¹ DNA or NMR testing confirms you're getting the actual species — not a cheaper substitute. Our Lion's Mane extract carries Purity-IQ's Certified Authentic mark, which covers identity, purity and batch-to-batch consistency.

Purity-IQ: our authenticated extracts(opens in a new tab)

Clear extraction method

Bioavailability starts here

Mushroom cell walls are made of chitin — the same substance that gives crab shells their hardness. Without proper extraction, your body can't absorb them. Many brands sell dried powder with no extraction at all. This ends up being very expensive fibre.

See cultivation & processing

Honest concentration ratio

High numbers aren't always better

Extraction concentrates mushroom — 8:1 means 8kg of raw mushroom reduced to 1kg of powder. How far a species can be concentrated and still hold as powder varies: Lion's Mane tops out around 8:1; Reishi is stable well beyond it. A ratio with no measured bioactive beside it is a number, not evidence.

See the batch dossier

Format matters

How it's delivered affects what you absorb

Gummies require heat and additives that degrade sensitive compounds. Tinctures are mostly water and alcohol, so deliver small doses. Capsules protect compounds from degradation and deliver measurable, consistent amounts.

See the materials catalogue

Third-party tested

Potency, purity, heavy metals, microbial

Independent lab verification of potency, purity, heavy metals, and microbial contamination. If a company won't share their batch reports, ask why.

Download the test results

Certified organic

The substrate is audited, the result is tested

Mushrooms hyperaccumulate compounds from their environment — good and bad. Organic certification audits the growing medium; independent testing checks the result. Look for an established certifying body like the Soil Association.

See the organic certificate

Cultivation & processing

One species, one protocol.

First-season fruit from buried oak logs, cut before spore drop, extracted 16:1 in hot water and ethanol.

Protocol sheet · rev. 08 · one species

GL-01 01 / 01
Reishi fruiting bodies
Reishi
Ganoderma lingzhi

Fruiting body only. First-season fruit from short oak logs buried under forest shade, cut as the white rim closes with no spore-collection hold. Dual extract in hot water and ethanol.

Logs
Organic oak · felled in winter · steam-sterilised
Spawn run
22–28°C · dark · 60–90 days
Burial
Sandy soil · 1–3 cm cover · ~70% shade
Fruiting
24–28°C · 85–95% RH
CO₂
≤1,000 ppm · kidney-shaped caps
Harvest
White rim gone · before spore drop
Drying
40–50°C · ≤12% moisture
Learn more about Reishi

FAQ

Common questions.

These are the questions we get asked most.

Where are your mushrooms sourced?

Our mushrooms are sourced from the pristine, remote mountain regions of Southeast China, an area celebrated for its rich heritage and long-standing expertise in cultivating medicinal mushrooms.

This location, far removed from industrial areas, allows us to harvest organic certified mushrooms of the highest quality. Emphasising purity and potency, we select only the finest mushroom fruiting bodies, grown and wild-harvested in carefully protected environments.

Are your mushroom extracts made from mycelium or fruiting body?

We’ve chosen to focus exclusively on utilising the fruiting bodies of mushrooms for our extracts. While mycelium, the vegetative part of fungi, does possess beneficial properties, the industry-wide practice of growing mycelium on grain substrates (known as myceliated grain) often results in products with high starch content and significantly diluted levels of active mushroom compounds. This dilution potentially compromises the health benefits that these compounds can offer.

To avoid any ambiguity in the potency and purity of our products, we therefore opt for mushroom fruiting bodies. These parts of the mushroom are not only the most recognised and studied but are also rich in crucial bioactive compounds such as beta-glucans and triterpenes.

What is the recommended dose?

Our standard recommended dose is 1000 mg(about 1/2 teaspoon or 2 capsules) per day for general health and immune support. This dosage can be adjusted according to individual health needs and goals. It is important to consult with a healthcare professional for personalized advice, especially if you have specific health conditions or are taking other medications.

Should I take functional mushroom supplements with food or on an empty stomach?

It is generally recommended to take mushroom supplements on an empty stomach for optimal absorption of the active compounds. However, individual responses can vary, and some people may prefer or require taking them with a small amount of food. Listening to your body and making adjustments as needed is key, and consulting with a healthcare professional can provide additional guidance tailored to your specific needs.

How long should I take mushroom supplements?

Mushroom supplements are best taken consistently over an extended period — as part of a daily routine, rather than as a quick fix.

I'm not feeling anything, are they working?

Medicinal mushrooms, as adaptogens, generally show their effects over time with consistent use. The body’s response to these compounds varies from person to person; some may experience benefits within weeks, while for others it might take longer. Consistent, long-term use is key to experiencing the full range of benefits these mushrooms offer.

I'm nervous to start using mushrooms. Are there any side effects or safety considerations?

Medicinal mushrooms have been used safely for thousands of years. While allergic reactions or sensitivities are rare, they can occur. We recommend individuals who are taking medication or have preexisting health conditions consult with a healthcare practitioner before starting mushroom supplements.

What are the capsules made from?

Our capsules are made from hydroxypropyl methylcellulose(HPMC), a plant-derived material. This choice is in line with our commitment to natural, environmentally friendly, and health-conscious practices. HPMC is suitable for a variety of dietary preferences, including vegan, kosher, and halal diets, and is free from animal products, making it an excellent choice for those who prefer or require plant-based supplements.

Where can I download your lab reports?
Why don't you sell liquid extracts/tinctures?

The decision not to sell liquid extracts or tinctures is grounded in our commitment to offering the most potent and effective mushroom products. Most liquid tinctures on the market are predominantly composed of alcohol and water, with active mushroom compounds comprising only a small fraction of the total product. This means that customers are often paying for a product where the majority is water and alcohol, not the beneficial mushroom compounds. 

Additionally, the vast majority of scientific research on the benefits of medicinal mushrooms is based on studies using hot water or dual extracts in powdered form. This body of research supports the efficacy of powdered extracts over liquid forms in delivering health benefits. By focusing on powdered extracts, we ensure that our products are aligned with scientific evidence and provide a higher concentration of active compounds, offering greater efficacy and value to our customers.

What is the shelf-life of your products?

Our products have a shelf life of 36 months after opening. To ensure optimal preservation, they should be stored away from intense heat and light. 

Do you accept returns?

We accept returns within 30 days of delivery, provided the items are unused and in their original condition. Please note that we cannot accept returns of opened packages. While customers are responsible for the return shipping costs, we are committed to ensuring a smooth and fair return process. In cases of damaged or defective items, we request customers to contact us immediately for resolution, including replacement or refund as appropriate.

I have so many more questions, where do I find the answers?

You can find a comprehensive FAQ section on our website that addresses a wide range of common inquiries.

More questions Show fewer

TFMC

The power of mushrooms, advanced by mycologists.

The company manifesto, in seventy-four seconds. Filmed at Tremenheere Sculpture Gardens, near Penzance in west Cornwall.

1:14
Tremenheere Sculpture Gardens, Cornwall16:9 · Sound on

The company manifesto, in seventy-four seconds. Filmed at Tremenheere Sculpture Gardens, near Penzance in west Cornwall.

Component by component

Materials catalogue

The four things in the box, what each one is made of, and what to do with it when it is empty.

Reviews

Customer reviews

Taking Organic Reishi? Share how it's going.

Photo of Organic Reishi sent by Gary Mills
Photo 1 of 5

Highlight

Give it a few weeks

Nothing for the first fortnight and I nearly cancelled. Week three I started sleeping through. Give it a few weeks before you make your mind up.

Gary Mills10 Feb 2026

Photo 1 of 5

103 customer reviews

18 Jul 2026

5.0

A capsule I can manage

I've had reishi as a tea and as a tincture before and never kept either up, too much faff. A capsule after dinner I can manage. It's become part of my evening routine along with turning the big light off and putting my phone in the kitchen. Three months in, I'm calmer in the evenings and I sleep more soundly, and on the rare night I forget I do notice. People complain about the price of good supplements but I spent more than this a month on wine I didn't need.

Sally-Anne Brook

23 Apr 2026

5.0

I have spent a small fortune on sleep over the years. Pillow sprays, weighted blanket, an app that plays rain. So I ordered this with my arms folded. First week nothing. Second week I thought maybe. By the end of the month I'd had more decent nights than bad ones for the first time in ages, and I'm not lying there with my brain doing laps. It hasn't fixed everything, a stressful day is still a stressful night. But it's the only thing in that long list I'd buy again.

Gemma Stokes

20 Feb 2026

5.0

Falling asleep was never my problem. Staying asleep was. I'd be out by 10.30 and then wide awake at 3 with a list running through my head. A colleague who's into her mushrooms suggested reishi and pointed me here because, in her words, 'they don't cut corners'. I've been taking one each evening since early January. I still wake some nights but I go back off, which is the bit that's new. Feeling much more human at work. Recommended, and the packaging is a delight.

Vanessa Li

Showing 4 of 103

Product details

The full panel.

Dose, allergens, certifications and sourcing, spelled out in full.

Full ingredient panel

Organic Reishi 16:1 Fruiting Body Dual Extract
Ganoderma lingzhi

450mg (7200mg dry weight equiv)
beta-d-glucans >15%
triterpenes >4%
ganoderic acids > 1.75% 

Dosing guidance

Take 1 capsule in the evening, ideally on an empty stomach (a couple of hours after eating).

Store in a cool, dry place out of direct sunlight. Keep out of reach of children. Not to be taken as an alternative to a balanced diet. Do not exceed the recommended daily dose. Seek advice from a health professional if pregnant or nursing.

Shelf life: 36 months after opening at room temperature

Cultivation & extraction

Our Lion's Mane, Reishi, Maitake and Shiitake extracts are made from fruiting bodies, grown on wood with natural light, fresh air and spring water. Our Chaga is wild-harvested as conks from living birch trees. Our Cordyceps is liquid-fermented mycelium — the form used in the published research.

We use temperature-controlled extraction and vacuum-drying to condense the mushrooms into a high-concentration powder extract. Maitake and Shiitake are extracted in hot water; our other extracts use hot water and ethanol.

Allergens

Contains none of the 14 allergens regulated under UK food law.

The capsule shell is hydroxypropyl methylcellulose (HPMC), a plant-derived material. It is free from animal products and suitable for vegan, kosher and halal diets.

Certifications

Certified organic by the Soil Association, licence DA31648.

Lion's Mane extract carries Purity-IQ's Certified Authentic mark, which verifies identity, purity and batch-to-batch consistency.

Extraction is carried out in a facility certified to cGMP and ISO 22000.

Potency and contaminant testing by Altitude Consulting. B Corp certification pending.

Recycling

Our supplements are packaged in eco friendly mycelium packaging, a material made from mushrooms and straw.

To properly dispose of the packaging, simply break apart and place it in your organics bin or compost heap.

Also true of every batch

Standards we hold ourselves to.

Beyond the assay: how the company is run, what the pack is made of, and what the formula leaves out.

Certified organic
Species authenticated
B Corp pending
Registered vegan
Compostable packaging
Plastic-free packaging
Living wage employer

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