Green Vitriol — Safety & Interactions

Zao Fan · Melanteritum

Contraindications

  • Pregnancy
  • Active gastritis, peptic ulcer, or severe stomach irritation
  • Large unsupervised internal doses
  • Use as an ordinary decocted supplement

Cautions

  • Internal Zao Fan can cause nausea, abdominal pain, vomiting, constipation, or diarrhea if the dose is excessive or the stomach is weak.
  • Traditional practice generally prefers pills, powders, or external use rather than long boiled decoctions.
  • Because it is fundamentally an iron salt, modern medication-style absorption issues matter when it is taken internally.
  • MSK page not found - drug interaction data not available from Memorial Sloan Kettering integrative medicine database

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
Tetracycline or fluoroquinolone antibiotics - ferrous iron can reduce drug absorption
Levothyroxine - ferrous iron can reduce absorption
Antacids or high-calcium supplements - may reduce iron absorption from internal Zao Fan use

Pregnancy

Not recommended during pregnancy. Consult a qualified practitioner before any use.

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.