Bar soap

Bar soap is simply a cleanser in solid form. Traditional soap is made by saponification — reacting fats or oils with an alkali — which yields a cleanser with an alkaline pH, typically well above that of skin. Syndet bars, short for synthetic detergent, look similar but are built from milder surfactants and are usually formulated closer to skin's own slightly acidic pH.

That distinction matters more than the format. Healthy skin recovers from a brief pH shift, but repeated washing with a strongly alkaline cleanser can leave skin feeling tight and may disturb the acid mantle and the lipids of the barrier, particularly in dry, mature or eczema-prone skin. Hard water adds to the same tight, filmy feeling.

Bars are not automatically harsh and liquids are not automatically gentle — the surfactant system decides. If skin feels stripped afterwards, try a syndet bar or a low-pH liquid formula, keep water lukewarm, and moisturise while skin is still damp. Persistent dryness or itching is worth showing to a dermatologist.