Bu Gu Zhi (Psoralea Fruit)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Bu Gu Zhi?

  Commonly 5–10 g in decoction, consistent with standard materia medica ranges. It is traditionally stir-fried (often salt- or wine-processed) before use to moderate its properties.

  Source: Sacred Lotus sources & references (Bensky; Chen & Chen). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Bu Gu Zhi?

  Bu Gu Zhi is contraindicated in Yin-deficiency heat patterns — symptoms such as a dry mouth, dry/sore throat, constipation, nocturnal emissions, hematuria, or urinary tract infection — because its warming, yang-tonifying nature can aggravate heat and dryness. It is also traditionally used with caution during pregnancy. It is best used only under a qualified TCM practitioner.

  Source: Sacred Lotus sources & references (Bensky; Chen & Chen materia medica cautions).

Chinese Herb Toxicity & Overdose

• Is Bu Gu Zhi (Psoralea corylifolia) toxic to the liver?

  There is a substantial, documented hepatotoxicity literature for Psoralea corylifolia — published case reports of acute cholestatic hepatitis and, in at least one case, fatal acute liver failure attributed to Fructus Psoraleae or Psoralea-containing products, alongside a formal review noting “probable” causality by standard causality-assessment methods for a Psoralea-containing Ayurvedic product. Laboratory and animal studies (zebrafish and rat models) have identified bakuchiol and related constituents (including 4-hydroxylonchocarpin and corylifol A) as candidate hepatotoxic compounds, with proposed mechanisms involving disrupted bile-acid and lipid metabolism (cholestatic injury). This is reported here as neutral, public safety-relevant reference information, not as usage guidance.

  Sources: PMID 16255343 (case report, acute cholestatic hepatitis); PMID 30975110 (case report and literature review, acute liver failure; notes six prior English-language cases); PMID 19841509 (Ayurvedic Psoralea-containing product, probable hepatotoxicity by CIOMS assessment); PMID 28639266 (rat model, bakuchiol-induced cholestatic hepatotoxicity); PMID 38449808 (zebrafish model, hepatotoxicity of Psoralea corylifolia extract); PMID 37598872 (candidate hepatotoxic constituents). Reference information, not a safety guarantee or treatment instruction.

• This herb is considered toxic.
  (while some Chinese herbs are toxic, it must be noted that many come prepared, or are combined, to mitigate their toxicity)

Herb-Drug Interactions

• No well-established clinical herb–drug interaction list is documented for Bu Gu Zhi, but given the hepatotoxicity literature above, concurrent use with other hepatotoxic medications or in anyone with pre-existing liver disease is a reasonable safety concern for professional awareness — this is precautionary, not a demonstrated specific interaction. Separately, Psoralea-derived psoralens are photoactive compounds (see research), so combining Bu Gu Zhi with photosensitizing drugs or prolonged UV/sun exposure is a plausible theoretical concern rather than a documented clinical interaction. (Flagged for practitioner confirmation.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Bu Gu Zhi (Psoralea corylifolia)?

  Yes — extensive phytochemical, pharmacological, and safety research, including a well-documented photosensitivity mechanism. Psoralea corylifolia was the original source of psoralen, a furanocoumarin compound whose photoactive chemistry underlies both its therapeutic use in PUVA photochemotherapy for psoriasis and vitiligo, and its capacity to cause skin photosensitization (heightened sunburn/rash risk with UV exposure) — this dual nature is a well-established feature of psoralen chemistry, reported here as reference information, not usage guidance.

  • Photoactive chemistry (psoralen) — a 2023 review describes psoralen as a furanocoumarin used historically in photochemotherapy for psoriasis, vitiligo, and leukoderma, alongside anticancer, anti-inflammatory, and anti-osteoporotic research interest; the same photoactivity that enables PUVA therapy is the basis of concern about photosensitivity with unsupervised sun/UV exposure.
  • Bone-health research (efficacy alongside toxicity) — a 2026 meta-analysis specifically evaluated both the efficacy and hepatotoxicity of Psoralea corylifolia for postmenopausal osteoporosis, reflecting the field’s current framing of the herb as pharmacologically active but requiring safety scrutiny.

  Overall, the modern literature on this herb is unusually explicit about balancing documented pharmacological activity against a real, published hepatotoxicity and photosensitivity profile; this is presented strictly as research context, not a therapeutic or safety claim.

  Sources: PMID 37752710 (psoralen phytochemistry/pharmacology review); PMID 42331197 (efficacy and hepatotoxicity meta-analysis, postmenopausal osteoporosis); hepatotoxicity sources cited above. Research context, not a therapeutic claim.

Chinese Herb Notes

• What formulas is Bu Gu Zhi part of, and how does it combine with other herbs?

  Bu Gu Zhi is best known as a core herb of Si Shen Wan (“Four Spirits Pill”), the classic formula for Kidney/Spleen-yang-deficiency diarrhea, where it is combined with Rou Dou Kou (nutmeg), Wu Zhu Yu, and Wu Wei Zi. Its dual role — warming Kidney yang while also warming the Spleen — is why it bridges Kidney- and Spleen-yang tonification in the same prescription rather than being used purely as a Kidney herb.

  Sacred Lotus’s own formula records also link Bu Gu Zhi to Hei Xi Dan and Qi Bao Mei Ran Dan, both classical yang/essence-tonifying and hair-darkening prescriptions. (Traditional formula context, not treatment advice.)

  Source: Sacred Lotus sources & references (formula cross-links); Bensky, Materia Medica (3rd ed.).

This herb is considered toxic