No, it’s a common 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 any tolerance can build up to the Zinc Pyrithione (ZPT) in our anti-dandruff shampoos.
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’). Plus, Head & Shoulders performed just as well through the final month as it had in the first.
So keep using Head & Shoulders and you’ll stay protected against flakes.