This is the pattern that frustrates people the most: the scalp finally calms down, shedding slows, and then a few weeks later it's back like nothing worked. It's not bad luck — dandruff-related hair fall relapses for a few predictable reasons.

The most common one: stopping the routine entirely the moment things look good. Medicated shampoo gets used less, then not at all, and within a few weeks the same oil-and-fungus cycle restarts from scratch. Most dermatologists recommend a maintenance phase — dropping the medicated shampoo to once a week instead of stopping completely — rather than quitting the routine outright.

The second reason: sticking with the exact same active ingredient indefinitely. Fungus can become less responsive to a single active over months of continuous use. Rotating between ketoconazole, zinc pyrithione, and selenium sulfide every few weeks tends to keep the fungus from adapting, which is why a lot of long-term routines alternate actives rather than using one forever.

The third, quieter reason: seasonal and stress-related triggers. Oil production shifts with weather, and cortisol spikes from stress genuinely increase sebum output. A routine that worked fine in one season can need a slight adjustment — a bit more frequent washing, for example — when the weather or stress levels change.

None of this means the original treatment failed. It usually means the maintenance phase got skipped. There's a full explanation of how to build that maintenance routine, plus the ingredient rotation approach, in this guide to hair fall due to dandruff and oily scalp.

General information only, not medical advice.

About the author: Content reviewed with reference to dermatology guidance from MedEasy.