Kali phosphoricum may be used as a Homeopathic or used simply as a micro-nutritional (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, Kali phosphoricum has demonstrated effectiveness against the following symptomology: "Corresponds to nervous dreads, over-sensitiveness to noise, restless and suspicious, ill effects of fright, grief, fear, sleeplessness, excessive and exhausting mental labor. It is one of the best remedies we have (for neurasthenia) and is probably often indicated. All observers agree that it is the most useful of the various phosphates." (Dewey)It has also demonstrated effectiveness against the following symptomology: corresponds to states of adynamia and decay; conditions arising from want of nerve power; -"remember it in treatment of suspected malignant tumors"; (Boericke) -clinical conditions: anemia; atrophy; brain, softening of; carbuncle; dysentery; gangrene; paralysis; pneumonia; puerperal fevers; ulcers (of skin); whitlow; septic states and septic fevers, noma, scurvy, typhoid and typhus fevers (Clarke) -"Kali phosphoricum is indicated when there is enzyme damage in the cells...especially indicated in reversible enzyme blockages such as may occur after retoxic treatment of influenza or infectious diseases...presenting symptoms of autonomic dystonia with nervousness, depressive moods, weakness of memory, anxiety, sleeplessness and in serious cases of melancholia with a hysterical and hypochondriacal element...chronic inflammations are also typical of the indications...sequelae of serious septic illnesses especially after retoxic (ie, allopathic) treatment.." (Reckeweg)

Kali phosphoricum is especially useful in certain Homeopathic potencies for mental exertion: -indisposition to meet people; -anxiety, nervous dread, lethargy; -extreme lassitude and depression; very nervous; -loss of memory; brain-fag; -cerebral anemia; headache of students and those worn out by fatigue; -slightest labor seems a heavy task; -worse excitement, worry, mental and physical exertion (Boericke).