Soap is more harsh as it can be more drying and irritating to skin. SLS and SLES are more efficient detergents however so in that sense, they are more stripping.
Overall, you’ll have a better experience using synthetic detergents versus soap for both hair and skin care products.
Interesting. I ask because I have a shaving soap that is real soap that chaps the hell out of my lips and this other synthetic one that doesn’t. What I find odd about the synthetic shave “soap” is while having synthetic detergents it contains triethanolamine, which I know to be alkaline. If you’re using synthetic detergents, why make the product alkaline? Is it because bases tend to feel slicker? Is the high pH going to help make mineral buildup in the sink?
Triethanolamine is used to raise the pH. However, that doesn’t mean that the overall system will be basic, just less acidic. Typically, synthetic detergents are used in systems that have a pH 5-6 for skin products.
pH does not have much impact on the mineral buildup in sink. That is caused by a reaction with soap molecules and metal ions in your water.
It could be that it makes the product feel more slippery when using it. I don’t think this is a good idea because it could harm skin and there are better ways to do that, however, that would be my guess for the high pH.