Blue Vitriol

Traditional Use

Primary Actions

• Induces vomiting to expel thick phlegm or recently ingested toxins - a drastic emergency use reserved for severe phlegm obstruction of the throat, chest, or upper body.
• Resolves toxicity and clears putrid tissue - traditionally applied to mouth sores, severe gum disease, throat lesions, and toxic swellings.
• Dries dampness and corrodes pathological accumulations - especially in external preparations for ulcers, erosions, and stubborn local lesions.
• Promotes tissue regeneration after removing necrotic or infected material - a classical logic behind its inclusion in throat and oral powders despite its harsh nature.

Secondary Actions

• Dan Fan is the mineral copper sulfate pentahydrate and is far more often discussed in modern practice as an external or emergency-use substance than as a routine decoction ingredient.
• Calcined Dan Fan is traditionally preferred for many external indications because processing changes its harshness and handling characteristics.

Classic Formulas

• Dan Fan San (胆矾散) - classical powder traditions using minute amounts of Dan Fan for severe gum, mouth, or throat lesions where corrosive toxin-clearing action is desired.
• Er Sheng San (二圣散) - a throat-obstruction formula tradition pairing Dan Fan with Bai Jiang Can to expel phlegm and relieve acute blockage.

Classical References

• Me & Qi describes Dan Fan as sour, acrid, and cold, entering the Liver and Gallbladder channels to induce vomiting, resolve toxicity, dry dampness, remove putridity, and promote tissue regeneration.
• Shen Nong Ben Cao Jing historically records this mineral under the name Shi Dan, while later materia medica identify it with copper-bearing blue crystals from ore oxidation.
• Yi Lin Zuan Yao states that Dan Fan moves Liver wind, drains Liver fire, and removes toxins, while later commentators warn against using it for cold-constrained throat presentations.