what is the difference between shampoo and just soap or shower gel.

Question

And why is mens and womens shampoo so different.

In: Chemistry

Answer 1

While soaps & shampoo do share much of the same ingredients, that doesn’t tell the whole story.

* Soaps naturally tend to be *alkaline* ([basic](https://en.wikipedia.org/wiki/PH)). Most common brands, like Coast, Ivory, Dial, Camay and Nivea, are very strongly alkaline (pH >= 9).
* Shampoos are made to be low or neutral pH (pH < 7). That’s because [high pH can damage the hair](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158629/).

Hence it’s probably ok to use shampoo as soap (e.g., body wash); but probably not ok to use soap as shampoo.