Can Hei Shun Pian treat acne?
Acne, also known as pimples, might be treated with Heishunpian under medical guidance as an adjunct therapy, but it should not be used alone or if the patient's constitution is unsuitable. If in doubt, it is recommended to consult a doctor in advance. Detailed explanation is as follows:

Heishunpian has a pungent taste and is hot in nature; it is toxic and acts on the heart, spleen, and kidney meridians. It functions to warm and support yang energy, dispel cold, and relieve pain. According to traditional Chinese medicine (TCM) theory, acne might develop due to internal damp-heat or yang deficiency with cold stagnation. When acne is manifested as yang deficiency with cold stagnation and impaired circulation of qi and blood, Heishunpian may help alleviate acne by warming yang and dispersing cold, thereby improving the cold-stagnation condition within the body and promoting the circulation of qi and blood.
However, for acne patients with a heat constitution or yin deficiency with fire hyperactivity, using Heishunpian may aggravate internal heat pathogens, worsening acne symptoms such as increased redness and pain. Furthermore, since Heishunpian is toxic, its use must strictly control dosage and be conducted under the guidance of a qualified physician. Overuse or improper use may lead to toxic reactions, such as numbness of the tongue and lips, nausea, and vomiting.
In addition, Heishunpian may have contraindications with other herbs—for example, it interacts adversely with Banxia (Pinellia) and Gualou (Trichosanthes), among others—so it is important to avoid simultaneous use with these herbs during treatment.