Nothing pulls from the body free radical, poisonous molecular debris better than suction.
One misinterpretation of the marks that sometimes occur as result of Cupping are that they are bruises.
Unless the Cupping was done too strong in a contraindicated case, no "bruising" occurs.
What these marks under the skin are, post Cupping, is stagnation, dead cellular debris, pathogenic factors, and most importantly - Toxins being drawn out of the bio-system. Some capillary seepage occurs, but it is minimal to the acidic agents being removed.
Blood tests have been done to measure the levels of toxins, pesticides and acids being drawn out of the body with shocking results.