Magnesium Deodorant

EVERY INGREDIENT, EXPLAINED

What's in the bottle

• Distilled WaterBase / carrier

  INCI: Aqua

  Distilled water is the carrier — the medium in which the magnesium chloride dissolves and the essential oils disperse. We use pharmaceutical-grade distilled water rather than purified or tap water. The difference matters: tap water contains calcium, magnesium, chlorides, and trace organics that would react with our actives or introduce microbial load. Distilled water, produced by boiling and condensing, strips out the dissolved solids and kills any biological material in the same step. We then stabilise the formula without preservatives — magnesium chloride at our concentration is naturally antimicrobial, and the essential oils contribute further antimicrobial action, which is why the formula does not require parabens, phenoxyethanol, or the other preservative systems you will find in most water-based deodorants. The water is a vehicle, not a filler.

  Sourcing: Pharmaceutical-grade distilled. Not purified water, not spring water.

• Magnesium ChloridePrimary odour-control active

  INCI: Magnesium Chloride

  Magnesium chloride is the active. It works differently from an antiperspirant: it does not block sweat ducts the way aluminium chlorohydrate does. Instead, it slightly raises the pH of the skin surface and delivers magnesium ions that are inhospitable to the Corynebacterium and Staphylococcus species that metabolise apocrine sweat into the volatile thioalcohols and short-chain fatty acids we recognise as body odour. You sweat normally — the body has good reasons for that — but the bacterial fermentation that produces the smell is meaningfully disrupted. We source specifically from the Zechstein Sea deposit beneath the northern Netherlands, a 250-million-year-old evaporite bed 1,500 metres below the surface. This is the same material used in medical-grade magnesium products. It is USP-verified for purity, free of the marine contaminants that affect sea-water-sourced magnesium.

  Sourcing: Zechstein Sea evaporite deposit, Netherlands. USP-grade, 1500m deep extraction.

• Caprylyl/Capryl GlucosideMild plant-derived solubiliser

  INCI: Caprylyl/Capryl Glucoside

  Caprylyl/capryl glucoside is a plant-derived solubiliser — it lets the essential oils disperse evenly in the water-based spray rather than floating on the surface. It is synthesised from coconut-derived fatty alcohols (caprylic and capric) and corn-derived glucose through a sugar-ester reaction. The result is a gentle, sugar-based surfactant — in the alkyl polyglucoside family — that is notably non-irritating even on compromised skin. It does not foam meaningfully at the low concentration we use (approximately 1%), and does not interfere with the magnesium chloride's activity. We deliberately chose this over the older polysorbate-20, which is PEG-derived and carries a history of trace ethylene oxide contamination. The glucoside is a cleaner chemistry with an equivalent functional result. No SLS, no SLES, no PEGs in the finished formula.

  Sourcing: Coconut- and corn-derived. Alkyl polyglucoside class. Non-PEG.

• Bergamot Essential OilCitrus top-note

  INCI: Citrus Bergamia Oil

  Bergamot is the top-note of the scent architecture. It comes from the cold-pressed peel of the bergamot orange — Citrus bergamia — grown almost exclusively in the Calabria region of southern Italy, where the terroir produces the specific linalool/linalyl acetate ratio that gives bergamot its distinctive clean-citrus character. (Earl Grey tea is black tea flavoured with bergamot oil — same source.) We use the furocoumarin-free (FCF) grade, which has had the bergaptene removed via gentle distillation. Bergaptene is the photosensitising compound responsible for the photo-toxicity warnings on non-FCF bergamot; the FCF grade is safe for daytime application. At the concentration we use it (drops, not tablespoons), the scent presents for about 10–15 minutes before settling into the herbaceous base layer.

  Sourcing: Cold-pressed Calabrian peel, FCF (furocoumarin-free) grade.

• Kaffir Lime Essential OilThai citrus character — signature scent note

  INCI: Citrus Hystrix Oil

  Kaffir lime — properly Citrus hystrix, locally makrut — is Thai citrus. It is brighter, sharper, and more resinous than lemon or lime, with a terpene profile dominated by citronellal and beta-pinene. This is the scent most distinctive to the formula and the one that most signals its Bangkok origin. We use the cold-pressed peel oil, not the leaf oil (which is common in Thai cooking but carries a different, more aldehydic profile). The peel is a by-product of the Thai fruit trade — farmers sell the fruit and the peel goes to distillation. This is good sourcing: no land dedicated to deodorant ingredients, just use of what would otherwise be discarded. The scent character pairs with bergamot to broaden the top-note band without sharpening it further.

  Sourcing: Cold-pressed peel (not leaf). Thai-sourced, by-product of the fruit trade.

• Rosemary Essential OilHerbaceous middle note, mildly antimicrobial

  INCI: Rosmarinus Officinalis Oil

  Rosemary sits in the middle of the scent structure — after the citrus top-notes fade, this is the herbaceous layer that carries through the day. It is steam-distilled from the needles and flowering tops of Rosmarinus officinalis, and its character depends heavily on the chemotype. We use the 1,8-cineole chemotype (sometimes called camphoraceous rosemary), grown mainly in Morocco and Tunisia, which gives the cleaner, more medicinal character we want in a deodorant. The alternative, the verbenone chemotype, is softer and more resinous — beautiful in other contexts but wrong here. Rosemary's 1,8-cineole fraction also carries documented antimicrobial activity, which layers with the magnesium chloride's anti-odour mechanism. No synergy claims, but not nothing either. The scent persistence is 3–5 hours at our concentration.

  Sourcing: 1,8-cineole chemotype (not verbenone). Morocco/Tunisia sourced.

• Geranium Essential OilFloral base note, mildly antimicrobial

  INCI: Pelargonium Graveolens Oil

  Geranium is the base note — it persists longest on the skin and is what the formula smells like by late afternoon. It is distilled from the leaves and flowering stems of Pelargonium graveolens, chemically dominated by citronellol and geraniol — two monoterpenoids that also appear (at different ratios) in rose and citronella. The scent profile is rose-adjacent but more herbaceous, without the sweetness that makes rose oil feel perfumery. We use the Bourbon grade (so named for the Indian Ocean island of Réunion, formerly Île Bourbon), which is considered the reference standard for floral depth. Like rosemary, it carries incidental antimicrobial activity via the geraniol fraction. The scent pairs with rosemary across the middle-to-base transition without clashing with the bergamot/kaffir lime top.

  Sourcing: Bourbon grade (Réunion or Egyptian). Steam-distilled from Pelargonium graveolens.

• d-alpha TocopherolAntioxidant (vitamin E)

  INCI: Tocopherol

  Natural vitamin E (d-alpha is the naturally occurring stereoisomer, as opposed to the synthetic dl-alpha). Protects the formula's oxidative stability in the bottle and contributes its own antioxidant behaviour on the skin. Works in combination with the tocopherol fraction of prickly pear to give Bio Gold a multi-pathway antioxidant profile without synthetic preservatives.

  Sourcing: Natural d-alpha, not synthetic dl-alpha.