Home / Chinese Herb / PSORALEA FRUIT [补骨脂, BU GU ZHI]


Name : Psoralea FruitBuGuZhi-PsoraleaFruit_opt

Chinese Name : 补骨脂

Latin Name : Fructus Psoraleae


This herb is the fruit of the plant Psoralea corylifolia L.of the family Leguminosae. It is said to be transplanted originally from Persia (Now Iran). Today it is grown in th Henan and Sichuan Provinces of China. After collection in autumn, it is dried in the sun, and used unprocessed or stir baked with saltwater.

Psoralea is a strong aphrodisiac herb. Traditionally, it was used to tone the genital organs and to treat impotence, treatened abortion, the discomforts of pregnancy, insufficient erections, polyuria, incontinence of urine in children, and sexual disorders.

Use of Psoralea Fruit in TCM

Pungent, bitter in taste, and warm,  it acts on the kidney and spleen meridians.

Effects, Medicinal Uses, and Combinations

  1. Stimulate kidney yang:
  • For lumbago, psoralea fruit is commonly prescribed with eucommia bark and walnut kernel. It is also used with cuscuda (tu si zi) lycium fruit, epimedium, and walnut kernel, as in Bu Gu Zhi Wan.
  • For impotence, premature ejaculation, seminal emission, sexual inadequacy, and polyuria, it is blended with dodder seed, epimedium, and lycium fruit in a decoction.
  1. Invigorates deficient kidney and spleen: for diarrhea before dawn, psoralea fruit is used with nutmeg, schisandra fruit, and evodia fruit (wu zhu yu), as in Si Shen Wan (R-28).
  2. Treats skin ailments: the tincture preparation of psoralea fruit can be applied externally on the skin to relieve psoriasis, vitiligo, and alopecia areata (loss of hair).
  3. Treats frequent urination and enuresis in children: in its powdered form, 1.5. to 2.5 g daily before sleep is administered,or it is used with fennel in pills or capsules with good results.


In a decoction of 5 to 10 g. For external application, 0.5 to 1.0 percent alcoholic psoralea fruit tincture is used to treat common skin ailments, particularly for leukoderma (vitiligo), psoriasis, and alopecia areata.


People who are yin deficient, blood deficient, and have excess fire, with tooth pain, should use psoralea with caution.

Side Effects and Toxicity

No adverse reactions have reported at the suggested therapeutic dose. LD50 of the total oil of the herb, bakuchiol, and isopsoralen in mice by oral administration were 38 C 3.5 g/kg, 2.3 C 0.18 mg/kg , and 180 C 30 mg/kg, respectively.

Chemical Constituents

The fruit of the herb contains flavonoids, coumarins, monoterpenes. The flavonoid compounds isolated include corylifolin, bavachin, corylifolinin, isobavachalone, bavachromene, and neobavachalcone. The coumarins include psoralen, isopsoralen, psoralidin, isopsoralidine, angelicin, and corylidin. In the monoterpene group, the chemical bakuchiol was isolated. Other ingredients in the fruit, including volatile oil, fats, and alkaloids, have been isolated.

Pharmacological Findings

  1. Action on the coronary vascular system:
  • Dilates coronary arteries and increases blood circulation.
  • Corylifolinin enhanced cardiac contractility in guinea pids and rats, stimulated a frog heart, and counteracted heart failure due to lactic acid.
  1. Antitumorous.
  2. Action on the skin pigments: psoralea preparations increase dermal circulation and can cause the skin to produce new dark pigment.
  3. Prevents excessive bleeding of the uterus.
  4. Antisenility, diuretic, and uterine muscle contraction properties have been noted.

Clinical Findings

  1. The mixture of proralen and isopsolaren given orally, intramuscularly, or externally was effective in the treatment of vitiligo. In some cases, it was supplemented with sunlight or ultraviolet irradiation. The filtrate of psoralea fruit soaked in a 20 percent alcohol solution fo seven days can be used externally for vitiligo. The external application of the herb extract combined with sunlight radiation gave good therapeutic results.
  2. A 100 percent psoralea decoction was given intramuscularly at 3 ml daily to 120 subjects with psoriasis. After ten treatments, itching was significantly reduced and skin scaling decreased. After forty treatments, seventy-seven subjects had marked beneficial results, thirty-three subjects had moderate results, and ten subjects were unchanged.