Answer
To use Dermax Therapeutic Shampoo (benzalkonium chloride), wet hair, apply enough to lather richly (about a fifty-pence-piece amount for short hair, increased for longer/thicker hair), rub thoroughly into the scalp with fingertips and rinse; repeat if necessary, then remove as much lather as possible by hand before rinsing thoroughly under running water.
Sources for this answer
- Dermax Therapeutic ShampooDermal Laboratories Limited · emc · SmPC §4.2 Posology and method of administration · Version 6Document updated
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