Educational information, not medical advice — ask your doctor or midwife.
Bukuryo is a dried fungus used in Kampo, the herbal medicine of Japan. Its Latin name is Wolfiporia cocos. It is also known as Poria sclerotium.
The part used is the sclerotium, a hard pale lump that grows on pine roots under the soil. Kampo uses it to help the body pass extra water, to settle the stomach, and to support weak digestion. Kampo calls that last job a spleen tonic.
Here is the honest verdict. Bukuryo has been used for hundreds of years, but human trials of it on its own are very thin. Long use in a tradition is not proof that a herb works.
No one knows for sure how Bukuryo works. Most of what we know comes from lab dishes and animal tests, not from people.
Lab work points to two groups of parts. Triterpenes (fat-like natural chemicals) may make the kidneys pass more water and salt. Long sugar chains called polysaccharides may act on immune cells in the gut.
These findings are early. They do not prove that taking Bukuryo does the same thing in your body.
You will most often meet Bukuryo as dried white cubes or slices. These are simmered in water to make a decoction, which is a strong herbal tea.
Other forms are common in Japan. Granules (ekisu) are dried extract powders made by drug firms. Capsules, tablets and loose powder are sold too.
Bukuryo is also one part of many well-known Kampo formulas, such as Goreisan, Saireito and Ryokeijutsukanto. In China, ground Poria is baked into a sweet pastry called fuling cake.
Poria appears in the Shennong Bencao Jing, an old Chinese drug book written around 200 CE. It has been used across East Asia for about two thousand years.
Japanese doctors took it into Kampo and made it a staple. By the Edo period (1603-1868) it sat in a large share of everyday formulas. It is still one of the most used single drugs in Japan today.
Get emergency help if your face, lips or tongue swell, if a rash spreads fast, or if you struggle to breathe.
See a doctor the same week if swelling is new, sits in only one leg, or comes with breathlessness. Swelling can be a sign of a heart, kidney or liver problem that needs proper tests.
Also see a doctor if you feel weak, crampy or very dizzy, or if your problem has not improved after four weeks.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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