Organic Shiitake

  • Cholesterol Regulation
  • Digestive Health

4.8 (14 customer reviews)

Settled digestion and heart support. Supports gut health each day while keeping cholesterol in check.

30 capsules · 30 days supply

How would you like it?

Why most customers choose regular shipments:

Pause, swap or cancel any time
No contract or minimum order
  • Delivery on us every 30 days
  • Starter kit worth £54.99
  • Home-compostable refills thereafter

Included in your kit

  • Organic Shiitake, 30-day supply £39.00£27.30
  • Refillable borosilicate glass jar £14.00Free
  • Pocket Mushroom Guide Free
  • Royal Mail delivery £1.99Free

What’s included

  • Compostable capsule pack
  • One month supply

  • Ships same day
  • Delivery on us
  • 60-day guarantee

I’m a chef so I get through kilos of fresh shiitake a week… I’ve held up better than I normally do: fewer days feeling run down, and I got through August without my usual week of feeling like death.

Dom F Chef · Sep 2026

I prefer shiitake on its own to the general mushroom blend I was taking before.

Chloe T Reviewed Jun 2026

Independently certified

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

Ingredients Full product spec

  • ShiitakeOrganic · 8:1 extract
  • >27%Beta-D-glucans

About Shiitake

Shiitake is the only mushroom that contains eritadenine — a compound that lowers cholesterol through a mechanism distinct from statins, by inhibiting the enzyme S-adenosylhomocysteine hydrolase and accelerating cholesterol excretion. Clinical trials using 9g/day of dried Shiitake report 7–12% reductions in total cholesterol and 6–7% reductions in triglycerides. Our 8:1 extract concentrates these compounds to therapeutic levels in a single capsule.

Shiitake Benefits

  • Cholesterol Regulation

    Eritadenine accelerates the excretion and metabolic breakdown of ingested cholesterol. Because it works through a different pathway to statin medications, Shiitake may be a useful dietary supplement for those who are statin-intolerant or looking for complementary support. In clinical studies, daily consumption of dried Shiitake led to measurable decreases in both total cholesterol and triglyceride levels.

  • Metabolic Function

    Laboratory studies suggest Shiitake extracts may influence glucose metabolism, with data indicating reductions in plasma glucose levels and improvements in insulin response. Combined with its cholesterol-lowering properties, this positions Shiitake as a broad metabolic support — addressing lipid and blood sugar pathways through distinct mechanisms.

  • Immune Support

    Lentinan, Shiitake’s primary beta-glucan, is one of the most researched polysaccharides in mycology. It stimulates natural killer cells and macrophages, and is licensed as a pharmaceutical in Japan. Shiitake also shows consistently high antimicrobial activity in laboratory testing, including the strongest anti-candidal action among commonly studied mushroom species.

  • Digestive Health

    Shiitake contains 25–35% soluble and insoluble dietary fibre, including beta-glucans that act as prebiotics to support beneficial gut bacteria. This high fibre density, combined with its antimicrobial compounds, makes it a useful contributor to digestive function and microbiome diversity.

  • Nutritional Profile

    Beyond its bioactive compounds, Shiitake has an excellent nutritional base — high in B vitamins and pro-vitamin D2 (ergosterol), which converts to vitamin D when exposed to UV light. It’s the second most widely cultivated mushroom in the world, with a long culinary history that speaks to both its palatability and its track record as a dietary staple.

We supply one of the most concentrated Shiitake extracts available, clinically dosed and third-party verified for potency. Each capsule serving contains the dry-weight equivalent of 3,600mg of Shiitake.


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

Certification

Certified organic.

We're inspected and certified organic by the Soil Association. Our current certificate is below.

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. Four of them are listed here. Run the same four on anyone else.

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.

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.

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.

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.

Fruited cold on oak logs, harvested as the veil breaks, extracted 8:1 in hot water.

Protocol sheet · rev. 08 · one species

LE-01 01 / 01
A cluster of Shiitake
Shiitake
Lentinula edodes

Cap and stipe from a low-temperature strain, fruited cold on oak logs through winter and spring for thick donko caps. Dried on a rising ramp and extracted in hot water.

Substrate
Organic oak logs · 10–20 cm · felled dormant
Spawn run
12–18 months · shaded · log moisture ≥35%
Induction
12–24 h cold soak · water ≤15°C
Fruiting
8–16°C · 75–90% RH · ≥8°C day–night swing
Harvest
Veil just broken · margin still inrolled
Drying
40°C ≤3 h · ramp to 60°C · ≤10% moisture

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 Shiitake? Share how it's going.

Photo of Organic Shiitake sent by Jan A
Photo 1 of 3

Highlight

Arrived today. Lovely bottle. Just taken the first one so too early for anything else.

Jan A20 Jul 2026

Photo 1 of 3

14 customer reviews

17 Sep 2026

5.0

I'm a chef so I get through kilos of fresh shiitake a week, and I was curious what an extract would be like. Different thing entirely, of course, no flavour to speak of. I've taken it since July as a general wellbeing thing during a brutal summer season in the kitchen. I've held up better than I normally do: fewer days feeling run down, and I got through August without my usual week of feeling like death. Service was friendly when I asked whether I could take it with food. Good people.

Dom Fairley

3 Sep 2026

4.0

Hard to judge

No obvious change after a month. Quality seems excellent, it's just hard to know what it's doing.

Mr R Martin

27 Jun 2026

5.0

Prefer this

I prefer shiitake on its own to the general mushroom blend I was taking before.

Chloe T

Showing 4 of 14

Product details

The full panel.

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

Full ingredient panel

Organic Shiitake 8:1 Hot-Water Extract
Lentinula edodes

450mg (3,600mg equivalent)
Beta-D-glucans >27%

Dosing guidance

Take 1 capsule each morning on an empty stomach.

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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