Indicated for Cramps, Colic, Dry Cough. Magnesia phosphorica is a homeopathic remedy often used for cramps everywhere. Indications for its use include being worse from cold water, cold air and touch and better from warm applications, pressure and bending double. Cramps may come and go. Magnesia phosphorica is a mineral remedy. Active ingredient: Magnesia phosphorica [HPUS]. Inactive ingredients: Sucrose/lactose pellets.