How often should I use it and how long does the colour last?

Because the pigments sit on the hair surface, they wash out progressively with each shampoo. Most users find the noticeable tone lasts about 3–6 washes, depending on hair porosity, water hardness, and how frequently you wash. The 40 ml sachet is sized for a single full-head application on short to medium hair; longer or thicker hair may need two sachets.

Treat it as a colour-refresh step, not a daily cleanser. Use it when your brown shade starts to look flat, warm tones need deepening, or grey roots become visible — typically every 1–2 weeks. On off weeks, use your regular shampoo and conditioner. Overuse on porous ends can build up excess pigment, making tips look darker than roots. If that happens, skip the toning shampoo for a few washes and focus conditioner on the ends to help the colour fade evenly.