Magnesia phosphorica is used as a Homeopathic medicine (tissue salt). Homeopathic potencies accredit their strength and efficacy to the electromagnetic signatures of the original substrate; these are scientifically created dilutions and succussions of medicines such that generally not even a molecule of the original substrate or medicine is present in the medicine.

As a Homeopathic or used simply as a micro-nutritional, Magnesia phosphorica has demonstrated effectiveness against the following symptomology: "Indicated in tired, exhausted, neurotic subjects when suffering from darting, spasmodic pains which are relieved by pressure and warmth...it should be remembered in chorea, and contractions of single muscles, and cramps such as writer's cramp..." (Blackwood)

-"The great antispasmodic remedy...cramping of muscles with radiating pains..neuralgic pains relieved by warmth...especially suited to tired, languid, exhausted subjects...indisposition for mental exertion;" -twitching of eyelids; supraorbital pains worse right side relieved by warmth externally applied; -severe neuralgic pain in ears, worse behind right ear; -toothache better by heat and hot liquids; -hiccough with retching day and night; -enteralgia relieved by pressure; -ovarian neuralgia; -intercostal neuralgia; -nervous spasmodic palpitation; constricting pain around heart; -involuntary shaking of hands; chorea; twitchings; tetanic spasms; darting pains in limbs; -sciatica, feet very tender; -weakness in arms and hands, fingertips stiff and numb (Boericke)