Ingredient dictionary
Sodium Monofluorophosphate
Sodium Monofluorophosphate is a fluoride salt, mostly used in toothpaste as a source of fluoride, a mineral used in oral care. Checked against our library November 6, 2026.
The catch: none for most people; check the full product list if your skin reacts easily.
What Sodium Monofluorophosphate does
- Supplies fluoride in toothpaste formulas
- Acts as an active, not a filler
- Used in oral care rather than leave-on skincare
Sodium Monofluorophosphate is a man-made salt. It is made by chemical synthesis, not taken straight from nature. Its job is to deliver fluoride, a mineral that dental care products have used for a long time. Because it is a salt, it dissolves in the water part of the paste.
Formulators often pick it over simpler fluoride salts when a toothpaste also contains calcium-based polishing powders. In those pastes it tends to stay stable, so more of the fluoride stays available in the formula. On a label it appears as one line among many, so it is easy to overlook.
Good for
Most useful to readers checking a toothpaste label, since it belongs in oral care rather than skin or makeup.
Be careful if
Nothing in particular for most skin types.
Frequently asked questions
Is Sodium Monofluorophosphate safe to use?
In toothpaste, it is generally well tolerated when used as directed. Brush as the label says, spit out the rest, and keep toothpaste away from young children, who can swallow it.
Is Sodium Monofluorophosphate the same as sodium fluoride?
Both supply fluoride, but they are different salts. Sodium monofluorophosphate has a phosphate part in its structure, which is one reason it behaves differently in some pastes. Either one may appear on a toothpaste label, and both are fluoride sources.