Arrowroot powder works well for hair, primarily as a natural dry shampoo that absorbs excess oil from your scalp. It’s a fine, lightweight starch derived from the tropical Maranta arundinacea plant, and its oil-absorbing properties make it a popular alternative to commercial dry shampoos. That said, it’s not a miracle ingredient for hair growth or repair. Its real strength is keeping your roots looking fresh between washes.
How Arrowroot Absorbs Scalp Oil
Arrowroot powder is 87 to 91% carbohydrate, almost entirely in the form of starch. That starch is what makes it so effective at soaking up sebum, the natural oil your scalp produces. When you sprinkle or pat arrowroot onto your roots, the fine starch particles bind to the oil and lift it away from your hair strands, giving them a cleaner, more voluminous appearance without water.
The powder also absorbs moisture, which is why it shows up in deodorants and body powders too. For hair, this means it can help on humid days when your roots go flat or limp. It won’t strip your hair of moisture the way some chemical-based products can, but it does sit on the surface of the scalp and hair shaft rather than penetrating it.
Arrowroot vs. Cornstarch for Hair
Both arrowroot and cornstarch absorb oil, but arrowroot has a noticeably finer texture. This matters for hair because finer particles blend in more easily and don’t leave as much visible residue. Cornstarch tends to sit on top of the hair and skin rather than disappearing into it, which can look chalky, especially on darker hair. Arrowroot creates a lighter, silkier finish and feels less gritty when you work it through your roots.
Arrowroot is also generally better tolerated by people with sensitive scalps. Research on arrowroot in cosmetic formulations describes it as non-irritating and suitable for sensitive skin types, including use in baby care products. Cornstarch can sometimes feel heavier and is more likely to clump when it encounters moisture.
Trace Nutrients in Arrowroot
Arrowroot rhizomes contain minerals like potassium, iron, zinc, calcium, and magnesium, along with several B vitamins including niacin, thiamin, and riboflavin. Some of these nutrients (zinc and iron in particular) play known roles in hair health when consumed as food. However, the processed starch powder you buy for cosmetic or cooking use is highly refined. Lab analysis of arrowroot starch shows it contains less than 1% protein and under 0.3% fat, with only trace amounts of minerals remaining.
In practical terms, dusting arrowroot powder on your scalp won’t deliver meaningful nutrition to your hair follicles. If you’re interested in arrowroot’s mineral content for hair benefits, eating it as part of your diet would be a more effective route than applying it topically.
How to Use It as Dry Shampoo
The simplest method is to dip a large makeup brush or your fingertips into a small amount of arrowroot powder and tap it onto your roots, focusing on the oiliest areas (usually along your part line and around your temples). Let it sit for a minute or two, then massage it in and brush through your hair to distribute it evenly.
If you have dark hair, plain arrowroot will leave a white cast. You can fix this by mixing it with cocoa powder or activated charcoal. A common ratio for brunettes is one cup of arrowroot powder, two tablespoons of cacao powder, and two teaspoons of finely ground activated charcoal. If your hair is lighter, reduce the cocoa and charcoal so the color blends more naturally. Store the mixture in a sealed jar or shaker container.
A little goes a long way. Start with less than you think you need and add more if your roots still look oily. Over-applying creates buildup that’s harder to brush out and can leave hair looking dull or powdery.
Risks of Overuse and Buildup
Arrowroot is gentle, but it’s still a starch sitting on your scalp. The same risks that apply to commercial dry shampoos apply here. Using it too frequently without washing your hair in between can lead to product buildup that blocks pores on the scalp. Dermatologists have noted that this kind of buildup can trap bacteria against the skin, potentially causing inflamed hair follicles (small pimple-like bumps) or a condition called seborrheic dermatitis, which involves red, itchy, flaky skin and can contribute to hair loss over time.
The key is treating arrowroot powder as a bridge between washes, not a replacement for them. Using it once or twice between shampoos is generally fine. If you notice itching, flaking, or small bumps along your hairline or part, that’s a sign you need to wash your hair more thoroughly and cut back on the powder. People prone to dandruff or scalp conditions should be especially cautious, since starch in a warm, moist environment can encourage yeast overgrowth.
What Arrowroot Won’t Do
Arrowroot powder won’t strengthen your hair, promote growth, reduce breakage, or condition dry ends. It has no meaningful protein or fat content in its refined form, so it doesn’t nourish hair the way oils, protein treatments, or deep conditioners do. Claims that it “feeds” your hair follicles or stimulates growth aren’t supported by any clinical evidence.
What it does, it does well: absorbing oil, adding volume at the roots, and extending the life of a blowout or style. If that’s what you’re looking for, it’s an effective, inexpensive, and minimally processed option that works for most hair types and sensitivities.