Ingredient dictionary

Potassium Phosphate

Potassium Phosphate is a mineral salt, made from potassium and phosphoric acid, that mainly keeps a formula's pH steady. It is on the label of 17 products in our library. Checked against our library November 6, 2026.

The catch: none for most people; check the full product list if your skin reacts easily.

What Potassium Phosphate does

Buffers the formula's pH
Adjusts acidity to a skin-friendly range
Helps pH-sensitive ingredients stay effective

Potassium phosphate is made by combining phosphoric acid with a potassium base, such as potassium hydroxide. The result is a simple mineral salt that dissolves easily in water. It is one of the basic building blocks used to tune a formula's acidity.

Formulators use it mainly as a buffer. A buffer resists sudden changes in pH, so a lotion or cleanser stays near the level it was designed for, even as other ingredients are added. Skin is naturally slightly acidic, so formulas are often kept in a range close to skin's own level. It is usually used in small amounts and has little effect on scent, color or texture.

Good for

Most skin types, since it is a routine pH adjuster in body lotions, cleansers, hand creams and moisturizers.

Be careful if

Nothing in particular for most skin types.

Frequently asked questions

Is potassium phosphate safe for skin?

It is generally considered well tolerated at the levels typically used in cosmetics. It works as a pH adjuster rather than an active treatment, so it is not usually a reason for concern. As with any ingredient, a patch test is a sensible step if your skin reacts easily.

Why is potassium phosphate in my lotion?

Most lotions need a steady pH to stay stable and work as intended. Potassium phosphate helps hold the formula at its target level, even when other ingredients are added. You will usually find it listed near the end of the ingredient list because it is used in small amounts.