Medicinal mushrooms in the UK: separating evidence from hype

Which mushrooms are being studied, and for what

The term ‘medicinal mushrooms’ usually covers species with a long history in traditional medicine systems and an active research literature today:

• Reishi (Ganoderma species), studied mainly for polysaccharides and triterpenes.
• Turkey tail (Trametes versicolor), a common British bracket fungus, studied for protein-bound polysaccharides.
• Lion's mane (Hericium erinaceus), studied for compounds called hericenones and erinacines. In Britain it is rare in the wild and protected by law.
• Cordyceps (Cordyceps militaris and cultivated strains related to Ophiocordyceps sinensis).
• Shiitake and chaga, studied for beta-glucans and other compounds.

What the evidence shows so far

Most research on medicinal mushroom compounds comes from laboratory studies on cells and from animal experiments. These are useful for generating hypotheses but cannot show that a product benefits people. Human trials exist for some species and preparations, yet many are small, short, use different products and doses, and are sometimes funded by manufacturers. Results from one extract cannot be transferred to another product. Overall, the evidence is promising in places but far from the confident claims seen in marketing.

Quality, identity and safety of products

Two products labelled with the same species can be very different. Key questions include whether the product contains fruiting bodies or mycelium, whether mycelium was grown on grain and contains a large share of starch, which extraction method was used and whether beta-glucan content was measured. Contamination with heavy metals or pesticides and misidentified species are known problems. People who take medicines, are pregnant or have a health condition should talk to a doctor or pharmacist before using mushroom supplements.

How mushroom products are regulated in the UK

In Great Britain, mushroom supplements are regulated as food, not as medicines:

• Food supplements are covered by food supplements regulations, such as the Food Supplements (England) Regulations 2003, with equivalent rules in Scotland and Wales.
• Health claims must be authorised on the GB nutrition and health claims register. According to the Advertising Standards Authority, there are currently no authorised claims for mushrooms themselves.
• Disease claims: foods may not claim to prevent, treat or cure disease; medicinal claims are only allowed for products licensed by the MHRA.
• Novel foods: foods not widely eaten in the UK or EU before 15 May 1997 need authorisation from the Food Standards Agency. The ASA has warned that turkey tail and some cordyceps species are likely to be considered unauthorised novel foods.

Northern Ireland follows EU rules in many food areas, so check separately if you sell there.

Studying medicinal mushrooms at Fungaris

Our medicinal mushroom school teaches the topic as a science: biology of the species, chemistry of bioactive compounds, extraction and analysis, critical reading of clinical evidence, safety and regulation. The courses do not train practitioners to treat patients and make no health claims for any product. Students learn to read a clinical trial critically, to judge product labels and certificates of analysis, and to explain the UK rules on claims and novel foods to customers or colleagues.