No, it’s a myth that your hair and scalp build up a tolerance to particular active ingredients in anti-dandruff shampoos.
In 50 years of research we’ve never seen any evidence to suggest that a tolerance to the Zinc Pyrithione (ZPT) in our anti-dandruff shampoos develops.
In fact, Head & Shoulders scientists put this myth to the test in a clinical study that lasted 12 months, spanning all 4 seasons.
Over the course of the study, those people using Head & Shoulders shampoo had less scalp flaking than the group using ordinary shampoo (the ‘placebo’). Moreover, Head & Shoulders performed just as effectively in the final month as it had in the first.
So keep using Head & Shoulders and stay protected against flakes.