Deodorant vs Antiperspirant: How to Formulate an Aluminium-Free Deodorant That Works
Aluminium-free deodorant is one of the most requested DIY and indie-brand projects. It's also one of the easiest to get wrong: the classic internet recipe (coconut oil, baking soda, cornflour) leaves many people with red, stinging underarms. Let's do it properly, starting with what actually causes the smell.
Deodorant vs antiperspirant: not the same thing
- Antiperspirants reduce sweat, usually with aluminium salts that temporarily plug sweat ducts. In the US they're regulated as drugs.
- Deodorants tackle odour, not wetness. They're cosmetics.
- A product that does both is both, legally (FDA).
So an aluminium-free product is a deodorant, and it won't keep you dry. Set that expectation clearly on your label.
What really causes underarm odour
Fresh sweat is basically odourless. The smell appears when skin bacteria break down sweat, sebum and skin proteins into smelly compounds (DermNet). Research has pinned much of the work on Corynebacterium bacteria, which turn odourless sweat precursors into pungent acids and sulfur compounds (note: the authors worked for a major personal-care company) (James et al., FEMS Microbiology Ecology, 2013).
That gives you three ways to fight odour:
- Trap the smelly molecules.
- Slow down the odour-making bacteria.
- Mask with fragrance (the weakest route on its own).
The baking soda problem
Baking soda is alkaline, around pH 9, while healthy skin sits around pH 4.7 (see our pH guide). Put a strongly alkaline powder on thin, warm, often-shaved underarm skin every day, and irritation is a common complaint. If you use it at all, keep it low, or skip it for sensitive skin.
Better odour fighters
- Zinc Ricinoleate: an odour trapper. Rather than killing bacteria, it captures odour molecules around its zinc centre (Kuhn et al., 2000; note: most authors worked for the ingredient's manufacturer).
- Triethyl Citrate: a classic deodorant ester, thought to slow the enzymes bacteria use to make odour.
- Ethylhexylglycerin (Multifunctional): a skin-friendly deodorant booster.
- Gentle acidity: low levels of Mandelic Acid or Lactic Acid in a lotion or spray can make skin less welcoming to odour bacteria. Test carefully on freshly shaved skin.
- Moisture absorbers for a drier feel (not antiperspirancy): Tapioca Starch, Kaolin.
A stick deodorant blueprint
- Structure: Candelilla Wax or Beeswax, plus Shea Butter
- Glide: Caprylic/Capric Triglyceride or Jojoba Oil
- Odour team: zinc ricinoleate + triethyl citrate
- Feel: tapioca starch and a little kaolin
- Antioxidant: Tocopherol
- Fragrance: optional, low, and IFRA-compliant (see our essential oil safety post)
Prefer a roll-on? Make it as a light emulsion or gel, and remember it then needs a preservative.
About the aluminium worry
Many people switch because they've heard antiperspirants cause breast cancer. The US National Cancer Institute states there is no scientific evidence linking antiperspirants or deodorants to breast cancer (NCI), and the American Cancer Society says evidence of any increased risk is limited (American Cancer Society). Aluminium-free deodorants are a perfectly good choice. Just market them on what they do well (fresh, gentle, no residue) rather than on fear.
Honest claims
"Aluminium-free deodorant" and "helps neutralise odour" are fair. "Detoxes your armpits" is not. And if you sell an aluminium antiperspirant (Aluminum Chlorohydrate), check the drug or cosmetic rules in your market first.
Explore Deodorant & Antiperspirant Actives and Body Care Ingredients.