Individual Herbs Notebook

Ma Yin Hua

Pharmaceutical: Radix Rhododendra ovata
Taxonomy: Rhododendron ovatum

Other names: Ovateleaf Rhododendron Root

Category: Herbs that Clear Heat



Properties: None given

Meridans Entered:
Primary: None given


Traditional Actions/Indications:
  1. Clears Damp-Heat and resolves Sore Toxins
    Damp-heat vaginal discharge
    Swollen welling abscess and clove sores

Suggested Daily Dosage: 1-6g in decoction. See cautions regarding toxicity of rhododendrons.


Cautions: Large doses and prolonged use due to presence of Grayanotoxins found in all rhododendron species. Symptoms begin up to 3 hours after consumption and include neurological, cardiovascular and gastrointestinal signs such as nausea, vomiting, salivation, headache, blurred or double vision, sweating, weakness, hypotension, slow heart rate, fainting, drowsiness, drunkenness, hallucinations, seizures and death. BhaduriHauck (2016) estimates the lethal dose at 0.2% body weight, or approx 150g for a 75kg adult but adverse effects may be reported much sooner. There is no antidote but cardiovascular effects are usually treated with atropine, from belladonna, henbane or datura species.


Notable Constituents:
Does not appear in any formulae listed on this site
Research Links & References: (click to display)