Betula Alba Juice

Betula alba (birch) juice is primarily used as a water-phase solvent/humectant substitute for water, typically at moderate-to-high levels, and is generally well tolerated in leave-on products. However, as a natural botanical sap it can contain trace proteins/salicylates and other plant constituents that have caused occasional irritation or contact allergy in reactive/atopic individuals, so I cannot score it as exceptionally gentle or inert. In sensitive-skin routines with multiple actives, its contribution to cumulative irritation is usually low but not negligible, supporting a conservative “gentle” rating. Safety Notes: In mass-market leave-on products (creams/serums/toners), Betula alba (birch) juice is often used as a minor botanical/skin-conditioning component or as part of a blend, with commercial listings commonly placing it around ~0.1–5% when not used as the primary aqueous phase. At the high end, some consumer-available toners/essences and mists are marketed as “birch juice” and use it as the main solvent instead of water, reaching ~70–98% depending on whether humectants/solubilizers/preservatives are included. Rinse-off cleansers typically sit toward the lower-to-mid end due to cost and because water remains the usual primary diluent.