What Is Magnesium Hydroxide in Deodorant? | Pure & Bloom

What Is Magnesium Hydroxide — and Why Is It in Our Deodorant?

If you've read the label on your Pure & Bloom jar, you've seen it listed first: Magnesium Hydroxide. It's the lead ingredient in our deodorant formula — and if you're new to natural skincare, it might not mean much yet. Here's everything you need to know.

WHAT IS MAGNESIUM HYDROXIDE?

Magnesium Hydroxide (Mg(OH)₂) is a naturally occurring mineral compound. You may know it as the active ingredient in milk of magnesia. In deodorant, it's valued for its ability to neutralise odour gently and effectively — without the skin irritation that often comes with formulas that rely heavily on baking soda as their primary active.

HOW DOES IT WORK?

Body odour doesn't come from sweat itself — it comes from bacteria on the skin that break down sweat compounds into the substances we recognise as smell. Magnesium Hydroxide creates a mildly alkaline environment on the skin's surface that makes it harder for these bacteria to thrive. It won't stop you from sweating — that's by design. Sweating is how your body regulates temperature. A natural deodorant works with that process, not against it.

WHY LEAD WITH MAGNESIUM HYDROXIDE RATHER THAN BAKING SODA?

Most natural deodorants use Sodium Bicarbonate as their primary odour-fighting ingredient. It's effective — but for many people, high concentrations cause irritation, redness, and a disrupted skin barrier. The reason is pH: baking soda sits at around pH 8–9, while underarm skin has a naturally acidic pH of around 4.5–5.5.

Pure & Bloom leads with Magnesium Hydroxide — it carries the primary odour-neutralising work, supported by a smaller amount of Sodium Bicarbonate in a secondary role. This means the benefits of both, with significantly less potential for irritation.

WHAT ELSE DOES IT DO FOR SKIN?

Magnesium Hydroxide has a naturally soothing quality that suits underarm skin. It pairs with calendula extract and bisabolol for calming, mango butter and shea for nourishment, and arrowroot and kaolin for gentle moisture absorption. Together these treat your underarms as skin that deserves care — not just a surface to deodorise.

IS IT SAFE?

Yes. Magnesium Hydroxide is well established in food, pharmaceutical and cosmetic applications globally. All Pure & Bloom products are formulated in compliance with UK cosmetic regulations. Our essential oil blends are IFRA-compliant and 100% natural.

OUR SCENTS

All five cream deodorants use the same Magnesium Hydroxide-led base:
Blossom Soft — rose geranium, lavender, ylang-ylang, vanilla
Citrus Paradise — orange, mandarin, bergamot, grapefruit, lime
Cloud Serenity — bergamot, lavender, clary sage, amyris
Moss & Wood — vetiver, cedarwood, clary sage, bergamot
Grapefruit Calm — grapefruit, lime, cedarwood, vanilla

Find your scent → here

Pure & Bloom is handmade in small batches in Yorkshire, UK. 100% natural ingredients. No aluminium. No synthetic fragrance. No compromise.