Shang Lu (Poke Root or Phytolacca)

Chinese Herb Actions

Chinese Herb Dosage

• What is the dosage of Shang Lu, and why does it have a strict ceiling?

  Reference materia medica place the internal dose ceiling at roughly 3–9 g of the vinegar-processed root, decocted — this is a documented upper limit, not a target, and raw Shang Lu is not used internally. As a toxic harsh expellant, Shang Lu is recorded in the literature as a short-term, practitioner-supervised herb; it is never self-administered or used at the discretion of the general reader.

  • Processing is not optional. Raw Shang Lu is markedly more irritant than the vinegar-processed (cu shang lu, 邪商陆) form; a controlled comparison of raw versus vinegar-processed extracts found the processed material produced clearly reduced mucous-membrane irritation and inflammatory markers in animal and in-vitro models. Materia medica sources describe vinegar processing as reducing toxicity while the root is still aged and long-decocted before use.
  • The dose ceiling exists because the margin between an active dose and a toxic dose is narrow — see Toxicity below.

  Source: materia medica consensus (harsh-expellant dosage ranges, cross-checked across multiple reference texts); PMID 23947148 (raw vs. vinegar-processed toxicity comparison, Zhongguo Zhong Yao Za Zhi, 2013). Reference facts only, not a prescription or usage instruction.

Chinese Herb Contraindications & Cautions

• Are there cautions or contraindications for Shang Lu?

  Shang Lu is contraindicated in pregnancy and is documented as having caused teratogenic (birth-defect) effects — this is an absolute caution, not a relative one. It is also unsuitable for patients with Spleen/Stomach deficiency, deficiency-type (rather than excess-type) edema, or generally weak/frail constitution, since a harsh purgative can further damage digestive and overall qi in these presentations.

  • Pregnancy — do not use. Laboratory work on Phytolacca acinosa specifically found abortifacient (pregnancy-terminating) activity in extracts of the root itself (strongest in the seed, then root, then leaf), consistent with the traditional contraindication.
  • Not for deficiency patterns. Reserved, in the traditional literature, for edema/ascites in patients whose underlying constitution is strong enough to tolerate a drastic purge — not for chronic, deficiency-type fluid retention.
  • Raw root is for external use only; internal use calls for the vinegar-processed form (see Dosage).

  Source: this site’s own record caution record (pregnancy/teratogenicity); PMID 3121937 (abortifacient activity in leaves, roots and seeds of Phytolacca acinosa, Journal of Ethnopharmacology, 1987). Neutral reference safety information, not medical advice.

Chinese Herb Toxicity & Overdose

• Shang Lu is classified as toxic; its principal toxic constituents are phytolaccatoxin and triterpenoid saponins (the esculentosides), which affect the gastrointestinal tract and central nervous system. Reported poisoning follows a fairly consistent pattern — onset roughly 20 minutes to 3 hours after ingestion, with nausea, vomiting, severe watery (sometimes bloody) diarrhea, abdominal pain, dizziness, and headache; higher exposures have progressed to confusion, muscle twitching, seizures, and, in documented fatal cases, cardiac and multi-organ failure.

  • Marker toxin. Phytolaccatoxin has been specifically identified and quantified (by TLC-densitometry) as one of the main toxic constituents of Radix Phytolaccae, used for quality-control purposes.
  • Severity is dose-dependent. A U.S. poison-center review of 1,669 human Phytolacca americana exposures in Kentucky (mostly young children, mostly accidental low-level ingestion of berries) found exposures “generally well tolerated,” with 239 adverse events and no deaths in that series — contrasted with a separate case report of a fatal poisoning in a 50-year-old woman who consumed roughly 150 g of stir-fried Phytolacca americana leaves, who died of multi-organ failure within 33 hours. The Chinese Pharmacopoeia recognizes both Phytolacca acinosa and P. americana as source species for Radix Phytolaccae.
  • Hepatotoxicity (preclinical). A zebrafish-larvae study found Phytolacca acinosa extract produced liver-enzyme elevation and hepatocyte damage at higher test concentrations, via oxidative stress and apoptosis pathways — laboratory evidence, not a clinical dosing guide.

  Source: PMID 2092711 (phytolaccatoxin quantification, Zhongguo Zhong Yao Za Zhi, 1990); PMID 36332712 (Kentucky poison-center exposure series, Toxicon, 2022); PMID 40602544 (fatal Phytolacca americana poisoning case, Toxicon, 2025); PMID 34876912 (zebrafish hepatotoxicity study, Evidence-Based Complementary and Alternative Medicine, 2021), DOI 10.1155/2021/3303014. Reference information only, not a safety guarantee -- this herb requires professional supervision.

• 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 studies were found for Shang Lu. Given its traditional diuretic and purgative action, concurrent use with other diuretics, laxatives, or antihypertensive medication is a reasonable precaution for practitioner awareness — this is precautionary reasoning from its mechanism of action, not a demonstrated clinical interaction. (Flagged for practitioner confirmation; no PubMed-indexed clinical interaction study was located.)

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 Shang Lu (Phytolacca acinosa / Radix Phytolaccae)?

  Yes — the available research is mostly toxicological and preclinical (chemistry, animal, and poison-center data); we found no controlled human clinical trials of Shang Lu’s traditional water-draining use. The research base is concentrated on identifying its toxic constituents and characterizing poisoning risk, consistent with its status as a toxic herb.

  • Toxic marker compound — phytolaccatoxin was identified and quantified by TLC-densitometry as a principal toxic constituent of Radix Phytolaccae, supporting quality-control testing.
  • Processing reduces toxicity — a comparative study found vinegar-processed Phytolaccae Radix extract produced clearly reduced mucous-membrane irritation and inflammatory markers versus the raw extract in animal and in-vitro models, supporting the traditional vinegar-processing step.
  • Hepatotoxicity mechanism (preclinical) — a zebrafish-larvae study linked Phytolacca acinosa extract to liver-enzyme elevation, hepatocyte damage, oxidative stress, and apoptosis at higher concentrations.
  • Reproductive toxicity (preclinical) — extracts of the root (and more potently the seed) of Phytolacca acinosa showed abortifacient activity in laboratory testing, providing direct research support for the traditional pregnancy contraindication.
  • Human poisoning epidemiology — a U.S. poison-center series of 1,669 Phytolacca americana exposures (mostly accidental, low-level, pediatric) found outcomes generally well tolerated with no deaths, while a separate case report documents a fatal outcome after ingestion of roughly 150 g of cooked leaf material — together indicating a real, dose-dependent risk gradient rather than uniform severity.
  • Other pharmacology (preclinical) — total saponins from Phytolaccae Radix reduced proliferation and induced apoptosis in a rat model of estrogen-induced mammary gland hyperplasia, comparable to a tamoxifen control; unrelated to the herb’s traditional water-draining use and included here only as a marker of ongoing pharmacological interest, not a therapeutic claim.

  Overall: the modern literature supports the traditional toxicity profile and the value of vinegar processing, but does not yet include controlled human efficacy trials for Shang Lu’s traditional indications.

  Sources: PMID 2092711; PMID 23947148; PMID 34876912 (DOI 10.1155/2021/3303014); PMID 3121937; PMID 36332712; PMID 40602544; PMID 37284304 (DOI 10.3389/fphar.2023.1181730). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Shang Lu different from other harsh expellants like Gan Sui and Da Ji, and what does it combine with?

  Among the harsh expellants, Shang Lu is distinguished by draining fluid through both the urine and the stool at once, plus a topical detoxifying action that the others lack. Gan Sui and Da Ji (Euphorbia species) instead concentrate on fluid and phlegm lodged more specifically in the chest and flanks — Gan Sui is generally regarded as the strongest cathartic of the group, while Yuan Hua is warm (rather than cold) and considered the mildest; Qian Niu Zi acts faster but its effect is less sustained.

  • Shu Zao Yin Zi (“Dredge and Dig Out Decoction”) — a classical formula for severe generalized edema with constipation and dysuria, in which Shang Lu is a principal ingredient alongside Ze Xie, Chi Xiao Dou, Fu Ling Pi, Mu Tong, Bing Lang, and other water-draining/qi-moving herbs. This combination is a formula-level pairing rather than this site’s own record-recorded combo for this herb.

  Source: harsh-expellant category differentiation and Shu Zao Yin Zi composition cross-referenced against multiple independent TCM formula references (multiple online sources). No herb-combination records or composition records exist for this herb in this site’s own record.

This herb is considered toxic