What does arrowroot powder do in deodorant?

Short answer: arrowroot powder is a fine starch that absorbs surface moisture and gives a fat-based deodorant a dry, silky finish instead of a greasy one. It absorbs sweat that has already reached the skin — it does not reduce how much you sweat.

Two jobs in one ingredient

• Moisture absorption. Starch takes up surface dampness, so the underarm feels drier and there's less wet sweat for bacteria to work on.
• Texture. Tallow and coconut oil alone would feel like a balm. Arrowroot cuts the slip and gives the whipped formula its soft, powdery finish that disappears into skin.

Why arrowroot and not cornstarch or talc

Arrowroot is a very fine, neutral starch from the tropical arrowroot plant, and the organic version is easy to source consistently. Cornstarch works similarly but is coarser and, for us, harder to source organically at the quality we want. Talc is a mineral rather than a starch, and it doesn't fit a food-grade, four-ingredient formula.

What it doesn't do

It's not an antiperspirant, doesn't plug sweat ducts, doesn't kill bacteria, and doesn't treat any skin condition. Odor control in our formula comes from magnesium hydroxide; arrowroot handles moisture and feel.

Using it well

Because arrowroot is the drying element, application matters. Apply to clean, dry skin and rub it fully in — a pea-sized amount per underarm. Piling it on doesn't improve dryness; it just leaves residue that can mark a shirt.

Keep reading

Read about the base in why tallow works as a deodorant base, see every ingredient we use on the ingredients page, or shop the tallow deodorant itself.