Ingredient dictionary

Aluminum Sesquichlorohydrate

An aluminum salt used as the active ingredient in many antiperspirants. Its main job is to help reduce sweat at the skin's surface. It is on the label of 10 products in our library. Checked against our library November 6, 2026.

What Aluminum Sesquichlorohydrate does

Helps reduce sweat at the skin's surface
Forms a temporary gel in sweat ducts
Helps keep underarms feeling drier

Aluminum sesquichlorohydrate is made by reacting aluminum compounds with hydrochloric acid under controlled conditions. The word sesqui means one and a half, and it refers to the chloride content relative to aluminum in the salt. It is water-soluble, so it blends into water-based formulas.

Formulators use it because it is effective at reducing sweat and is common in sticks, roll-ons and sprays. As a formula dries, it can feel slightly powdery or tacky, and it may leave faint white marks on clothing. Some people notice mild itching or stinging, especially on freshly shaved skin, so a small test patch is a sensible first step.

Good for

People who want an antiperspirant to help reduce underarm sweat and wetness during the day.

Frequently asked questions

Is aluminum sesquichlorohydrate the same as an aluminum-free deodorant?

No. It is an antiperspirant active, which is a different category from deodorant. Deodorants mainly mask odor, while antiperspirants help reduce sweat. Check the front of the pack for the word antiperspirant.

Can aluminum sesquichlorohydrate irritate sensitive skin?

It can. Some people feel itching, stinging or redness, especially on freshly shaved or sensitive skin. If that happens, rinse the area, stop using the product, and check with a doctor if it lasts. Trying a small test patch first is a good idea.