SPZM is an empirical formula from Shanghai with added calcium and magnesium. White peony (bai shao) nourishes blood and alleviates pain. This herb also preserves yin and insures the smooth flow of Qi. If Qi is not flowing smoothly there will be emotional frustration, anger, abdominal distention, lump in the throat, and PMS in women. These factors can also cause Qi stagnation. Peony insures the sinews are moistened and nourished. Pueraria (ge gen), releases the muscle tension and clears heat. It is particularly useful for headache, stiff upper back and neck. Clematis (wei ling xian) dispels wind dampness, opens the channels, and alleviates pain. Spatholobus (ji xue teng) activates, and nourishes the blood. Licorice (gan cao) relieves spasms, particularly of the legs and abdomen, clears heat, and harmonizes the other ingredients. Magnesium is included as it calms spasms and muscles; calcium improves the uptake of magnesium and also has a calming effect.