Anti-dandruff shampoos can vary in their pH level, but most commercial shampoos, including those designed to combat dandruff, tend to be slightly acidic to neutral, with a pH range of around 4.5 to 7. This is because the natural pH of the scalp and hair is slightly acidic, typically ranging from 4.5 to 5.5. Formulating shampoos within this pH range helps to maintain the scalp's natural balance, which is important for overall scalp health.

However, some anti-dandruff shampoos might contain specific active ingredients that influence their pH. For example, shampoos containing zinc pyrithione, a common anti-dandruff agent, are often formulated to be closer to neutral. On the other hand, shampoos with salicylic acid or coal tar as active ingredients might have a slightly lower or higher pH respectively, to enhance the efficacy of these ingredients.

It's worth noting that excessively high alkalinity (high pH) can strip the scalp and hair of their natural oils, leading to dryness and potentially exacerbating dandruff issues. Therefore, even when formulating for specific treatments, shampoo manufacturers strive to balance efficacy with scalp and hair compatibility. Always check the product label or consult the manufacturer for the specific pH information of a given anti-dandruff shampoo.