Jackson's Mineral Salts #8 Magnesium Phosphate 6X - According to Dr. Schuessler and other homeopathic references, Magnesia phosphorica (Mag phos) is an important mineral salt in the body related to helping muscles and nerves relax. Menstrual cramping, stomach cramping, muscular cramping, shooting, darting, and spasmodic pains, neuralgia, sciatica, and neuritis are all related to an imbalance of this salt in the body.