Professional Formulas Ferrum Phosphoricum (Cell Salt 4) is a homeopathic formula that supports vascular system health and the transport of oxygen throughout the body. Use according to standard homeopathic indications for self-limiting conditions. Common Materia Medica indications: low fever, head cold, sleeplessness, sore throat, upper respiratory complaints. Recommended Use: Place drops under tongue 30 minutes before/after meals. Adults and children 12 years and over: Take 10 drops up to 3 times per day. Consult a physician for use in children under 12 years of age.