Monosodium phosphate is a compound of the counterion elements sodium and phosphate. It is often found in dental products due to its enamel-restoring qualities, and is sometimes used medicinally as a laxative. It is sometimes added to toothpastes in combination with other ingredients to prevent cavities and restore lost enamel, but it can also be purchased separately as a dental cleanser and protectant.
Most of the time, monosodium phosphate comes in crystal and powder forms. It is colorless and odourless. When used for oral health purposes, it is usually dissolved in water with one part monosodium phosphate to four and a half parts water. This combination can be applied directly to teeth to restore enamel and prevent tooth and gum disease. In some cases, it is also an ingredient in toothpaste and mouthwash.
Monosodium phosphate supplements are also available in food-grade tablets. These are not as potent as medicinal formulations and can be taken orally to supplement dietary phosphorus. Horses are commonly supplemented with monosodium phosphate for this reason. It is important not to overdose on these supplements because they can be hard on the kidneys if taken in higher than recommended amounts.
In medicine, monosodium phosphate is sometimes used as a stimulant laxative before certain operations and medical procedures. This is not recommended for all patients due to the negative reactions supplements can have on the kidneys. Sodium- and phosphorous-based laxatives have been discontinued in certain countries due to these risks as safer alternatives are now available.
Due to the risk of serious health complications, patients should not take medical-grade versions of monosodium phosphate without being under the direct supervision of a medical professional. It's also important to choose options that are specially designed for oral human consumption, as certain formulations can cause serious side effects. Anyone taking other medications or additional supplements should inform their physicians so that appropriate dosage recommendations can be made. People with kidney disease may not be candidates for these supplements.