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Inspired by the Japanese tradition of yu-su-ru—the ritual of strengthening hair through mindful care—the Izumi Tonic Thickening Serum is a lightweight, leave-in treatment designed to visibly enhance density, body, and resilience.
Infused with Izumi Tonic, inspired by rice water, this refined serum works to strengthen hair fiber while boosting the appearance of fullness and thickness from root to tip. The weightless formula absorbs instantly, leaving hair soft, flexible, and noticeably more voluminous—never stiff or sticky.
Designed as the finishing step in the Izumi Tonic ritual, this serum helps reinforce weakened strands, improve manageability, and create touchable body with a natural, healthy-looking finish. Hair feels fortified, fuller, and beautifully balanced.
Key Benefits:
Visibly enhances hair density and fullness
Strengthens weakened hair fiber
Improves body and manageability
Lightweight, non-greasy leave-in formula
Adds volume without weighing hair down
Ideal for fine to medium hair
Usage
Cleanse hair by applying the Strengthening Shampoo System. Rinse carefully and proceed by using the Strengthening Conditioner System or Strengthening Treatment System. To complete the routine, apply the Thickening Serum on lengths.
