Is cupping beneficial or harmful? Let's talk about it.

Cupping is indeed a kind of physical therapy, but at least in most of the introductions I have seen about cupping, it is classified as "massage" and called "a bloodletting therapy", which is the first time I have seen it. Because one of the most important functions of cupping is to use the pressure difference generated by adsorption to stretch muscles, nerves, blood vessels and subcutaneous glands locally, and its working principle is the same as massage. The most significant function is to help relax muscle tissue, the second is to expand local subcutaneous blood vessels and lymphatic vessels by negative pressure effect and adjust their contraction function and permeability, and the third is to produce some benign stimulation to local nerves and subcutaneous glands. Among them, the benign stimulation of cupping on local nerve tissue and subcutaneous glands and the effect of temporary stress on endocrine regulation belong to the so-called "soothing effect", and I have no opinion. And if relaxing muscle tissue and regulating vasomotor function of blood vessels and lymphatic vessels are also "soothing means, not therapeutic means", are Antan tablets, phenytoin, nicotinic acid, vasorelaxants and dibazol, which relax muscles and relieve spasms, also "placebos"?