Ingredient dictionary

Phosphoric Acid

Also listed as: Orthophosphoric Acid

Phosphoric acid is a mineral acid used in small amounts to adjust a product's pH, keeping formulas stable and gentle on skin. It is on the label of 7 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 Phosphoric Acid does

Lowers pH in acidic formulas
Offsets alkaline ingredients
Keeps pH in a stable range

Phosphoric acid is made from phosphate rock, which is treated with sulfuric acid and then purified for cosmetic use. Formulators use it to fine-tune pH, the measure of how acidic or alkaline a product is. Many ingredients push pH upward, and a small amount of phosphoric acid brings it back into a comfortable range.

Because it is used in tiny amounts, it is unlikely to change how a product smells or feels. It is a mineral acid, so it mixes easily with water-based formulas. Concentrated forms are strong and need careful handling, but finished cosmetics contain only small, diluted amounts.

Good for

Suits almost everyone, since it appears in small amounts to keep products at a comfortable pH for skin and hair.

Be careful if

Nothing in particular for most skin types.

Frequently asked questions

Is phosphoric acid safe in skincare?

In the small amounts used in finished cosmetics, phosphoric acid is generally well tolerated. It is there mainly to balance pH, not as a skin-care ingredient. People with very sensitive skin should still patch test new products, as with any formula.

Does phosphoric acid make a product more acidic?

Yes, it lowers pH, which makes a product more acidic. Formulators also use it to offset alkaline ingredients, so the final pH lands where the product works best and feels comfortable.