Also known as: Trametes versicolor, Coriolus versicolor, PSK, PSP, Yun Zhi
BotanicalGood evidence
A common bracket fungus and the most thoroughly researched medicinal mushroom, thanks to decades of supervised use in Japan and China. Standardised to beta-glucan and protein-bound polysaccharide content.
Typical dose
1.0–3.0 g per day
Split across the day, with food
What it is
Trametes versicolor is one of the most common fungi in the world, growing in overlapping fan-shaped brackets on dead hardwood, banded in concentric rings that give it its name. You will have walked past it in any British wood.
Two protein-bound polysaccharides are the compounds of interest: PSK, developed in Japan, and PSP, developed in China. Both have been used under medical supervision in those countries for decades, which is why turkey tail has a far larger research record than the other medicinal mushrooms.
As with the whole mushroom category, the fruiting body versus mycelium-on-grain question decides what you actually get. Beta-glucan content is the honest quality marker; total polysaccharide figures can be inflated by starch from the growing substrate.
How it works
Beta-glucans and the protein-bound polysaccharides interact with receptors on immune cells in the gut lining, modulating immune activity rather than simply stimulating it.
Turkey tail also acts as a prebiotic. Its polysaccharides reach the colon largely intact and are fermented by gut bacteria, shifting microbial composition, which is an increasingly emphasised part of how it may work.
Antioxidant activity has been described, as it has for most fungi in this category. The immune and prebiotic routes are the better characterised of the mechanisms.
What the evidence shows
Turkey tail has the largest body of supervised clinical research of any medicinal mushroom, accumulated over decades of use in Japan and China. That research sits in medical settings and is not a supplement application, but it does mean the compounds are unusually well characterised.
For supplement use in healthy people, the relevant evidence is thinner. Small trials have reported changes in immune cell populations and favourable shifts in gut microbiota composition.
Whether those changes translate into anything a healthy person would notice is not established. Turkey tail is the best-researched mushroom in this index, and that research mostly concerns a context that is not why it is sold in a tub.
Dosing
Common supplemental range is 1 to 3 g daily of extract, split across servings and taken with food.
Judge products on the same three points as any mushroom: fruiting body or mycelium on grain, declared beta-glucan percentage, and whether the extract is hot-water or dual-extracted. Beta-glucans are water-soluble, so hot-water extraction is the relevant method here.
A product declaring beta-glucan content is telling you something; one declaring only total polysaccharides may be counting the starch it was grown on. Effects reported in research accrue over weeks.
At a glance
Common forms
Hot-water fruiting body extract, PSK, PSP, Mycelium on grain, Within mushroom complexes
Half-life / duration
Not well characterised; effects accrue over weeks
Timing
Split across the day, with food
Competition status
Permitted — not on the WADA Prohibited List
Category
Botanical
Safety and side effects
Turkey tail is well tolerated, with a long record of use. Digestive effects such as gas, bloating and darkened stools are the most commonly reported and are generally mild.
Because it modulates immune activity, speak to your doctor before use if your immune system is being managed or suppressed for any reason.
Anyone sensitive to fungi or moulds should avoid it. Speak to your doctor before use if you take regular medication or are under medical care.
Who should avoid it
Speak to your doctor before use if your immune system is being managed, if you are under medical care, or if you take regular medication. Avoid if sensitive to fungi or moulds. Not established at supplemental doses in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
