Soap is a good cleanser to use on the skin as it is alkaline, with a pH of 10. However, the skin has an acidic pH of 5.5. Therefore, using soap will disrupt the skin’s natural acidity, causing dryness, and the skin will compensate by producing more oil to restore its pH balance. This makes your skin more prone to dryness when using it. When used to wash hair, soap can also damage the scalp, drying it out and altering the natural texture of the hair.
The second issue is that most of the water used for bathing today is hard water, containing calcium and magnesium ions. When this hard water reacts with soap, it forms salts, making the soap ineffective and leaving deposits on the skin and hair.
So, if you think your water is hard, it’s best not to use soap for washing. The solution is to choose a cleanser with gentle, mildly acidic ingredients for the skin and hair.