Third bottle, two honest months of use, and the flakes are still there. When dandruff keeps coming back, the product is rarely the problem. Work through these eight and you will almost certainly find yours.

1. It is not dandruff

Small, dry, powdery flakes with a tight-feeling scalp are dryness, not dandruff — and medicated shampoo drives that in exactly the wrong direction. Touch your scalp a day after washing: an oily film means dandruff, papery roughness means dryness.

2. You rinse it out immediately

The most common technical error by a wide margin. Zinc pyrithione and climbazole need three to five minutes of skin contact. Lather and rinse in twenty seconds and you will finish the bottle having delivered almost nothing.

3. You are washing your hair, not your scalp

Flaking happens on skin. If the lather sits on your lengths while the roots get a passing rinse, nothing changes. Massage along the partings with fingertips.

4. You wash too rarely

"Washing less will irritate it less" backfires. Accumulated sebum and scale are precisely what the yeast feeds on. Two or three washes a week while you are getting it under control.

5. Conditioner is landing on your roots

A film of conditioner or mask on the scalp undoes the shampoo. Mid-lengths down, always.

6. Same active for months

Skin and its flora adapt. Keep two products with different actives and swap every four to six weeks, with a mild shampoo in between.

7. You stopped as soon as it improved

Two weeks in it looks better, the medicated shampoo goes back in the cupboard, and a month later you are here again. Run three to four weeks of active treatment, then keep one medicated wash a week indefinitely.

8. The cause is not in the bathroom

Stress, short sleep, dry heated air, hard water, a hat worn all day, styling product buildup. Dandruff is a skin reaction, and skin reacts to more than shampoo.

When to stop troubleshooting

If you have corrected everything above and a full month of consistent care changes nothing — or if you have red patches, crusting, weeping or painful skin, flaking on the eyebrows, face or chest, or noticeable shedding — see a doctor or trichologist. Seborrhoeic dermatitis and psoriasis look like dandruff and need prescribed treatment; and you should see a doctor for significant hair loss without waiting a month first.

Faberlic carries mild shampoos suitable for rotation as well as scalp-focused options, including the plant-based Botanica line — see the current catalogue on faberlic.com. For the surrounding routine, see the haircare guide.