The roots petals used to make Indigo Herbs Mai Men Dong Tincture undergo stringent checks to ensure all of the roots develop to their fullest potential whilst adhering to exceptionally high quality standards. After careful selection and cleaning the plant material undergoes a process of cold percolation in order to extract the active constituents into tincture form. The cold percolation method employs a gradient circulation of the solution which keeps the plant ingredients in perpetual contact with the ethanol. This technique is faster and more efficient than maceration and ensures there is less waste of precious plant materials. This premium quality product is manufactured to GMP standards and Quality Assured by Indigo Herbs. It is 100% pure botanical ingredients, completely free of synthetic ingredients with absolutely nothing added.