Black Soybean — Safety & Interactions

Hei Dou · Sojae Semen Nigrum

Contraindications

  • Known soy allergy or hypersensitivity
  • Marked bloating or impaired digestion aggravated by beans and legumes

Cautions

  • Hei Dou is generally food-grade and mild, but concentrated soy supplements are not equivalent to ordinary culinary amounts
  • Large or concentrated soy intake may not be appropriate in every hormone-sensitive context, especially when used as supplement-style extracts rather than food

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
Tamoxifen Soy isoflavones such as genistein may antagonize tamoxifen effects on estrogen-dependent breast cancer Moderate Memorial Sloan Kettering Integrative Medicine - Soy
Aromatase inhibitors Soy-based supplements may affect treatment efficacy through estrogen-related and aromatase-related signaling Moderate Memorial Sloan Kettering Integrative Medicine - Soy
Levothyroxine Case reports suggest soy products may interfere with levothyroxine absorption Moderate Memorial Sloan Kettering Integrative Medicine - Soy

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.