Asda groceries direct to your door. Delivery from £3. Against dandruff & hair loss. With caffeine complex. Double effect shampoo Stage One: The Double Effect Shampoo loosens scaly, keratinous cells & helps remove dandruff from the scalp. Stage Two: With the scalp cleared of dandruff, the caffeine complex can penetrate into the hair root & help strengthen it against hair loss. Health & Beauty > Hair Care > Shampoo