The method of stimulating a substance is disclosed. The method has the steps of activating an acoustic shock wave generator or source to emit acoustic shock waves; and subjecting the substance to the acoustic shock waves stimulating said substance wherein the substance is positioned within a path of the emitted shock waves and away from a geometric focal volume or point of the emitted shock waves. In one embodiment the emitted shock waves are divergent or near planar. In another embodiment the emitted shock waves are convergent having a geometric focal volume of point at a distance of at least X from the source, the method further comprising positioning the substance at a distance less than the distance X from the source. The substance is a tissue having cells. The tissue can be an organ of a mammal. The mammal may be a human or an animal. The organ may be a heart, a brain, skin, a liver or a kidney or any other organ. The tissue may be muscle, cartilage, tendon, bone, teeth or gums. The tissue may be a part of the vascular system, a part of the nervous system, a part of the urinary or reproductive system, a part of the lymph node or pituitary systems, a part of the ocular system or a part of a skeletal system.