MICHAEL HOLLOWAY BSC, MSC
Have you ever typed "What is the best soap for dry skin?" into a search engine? What you invariably end up with is a list of soap that has been sponsored by big cosmetics companies. Yes, thats right, unfortunately most of the articles that appear at the top of the search results are from magazines and media outlets that have been PAID to give you a list of sponsored products. This kind of bias is to put it mildly, not ideal. It does not answer your question.
Big businesses pay journalists only to write about their soaps.
'Using a detergent supermarket syndet (fake soap) is like using washing up liquid to wash your face.'
What makes it worse is that VERY FEW of these products are going to relieve dry skin! Unless you haven't realised yet, they're all detergent based syndets, synthetic soap. Syndets are totally safe but will tend to make your skin drier. Yes, let me say that again, on the whole most of the leading brands (including dove) will over time make your skin more susceptible to drying out if not straight up dry it out. Why? Because they're not real soap, in a nutshell. Using a detergent syndet (fake soap) is like using washing up liquid to wash your face. Detergents don't work in the same way as a real soap bar (or liquid), they were invented to save businesses money. Which means they were not meant to do anything for you! the consumer. Detergent soaps, including most supermarket brands are a cost saving exercise for businesses, not a beneficial item for the average soap buyer.
So what is the answer? The best bar soap for dry skin is...actually drinking enough water. Fully 75% of people who have dry skin are dehydrated. So try to find ways to remind yourself to drink more (water not sugar). Also avoid tea and coffee if possible (or at least cut down) because they are diuretics. They make you LOSE water and become dehydrated, which means your body will 'suck' water away from non-vital organs, e.g., the skin, to conserve precious fluids. This will have the effect of drying out your skin. Pretty simple eh? But how? Well let's face it, we all love those troublesome smart phones these days. What I do is set a reminder every two hours or so and drink a tumbler or cup of water when it goes off.
OK, that's useful but it doesn't solve the soap issue really. Fair comment. Firstly stay away from supermarket soap if you have dry skin. You really need to invest in your skin if you want to see any improvement, it wont get better on its own. So the first thing is hydration and diet. Secondly buy some real soap products, that is, vegetable based soap. Only a vegetable based soap can adequately moisturise your skin. Big branded soap tends to contain moisturiser to make up for the drying effect it has on skin. Obviously this is a massive waste of time and like telling someone you'll clean their new car KNOWING you'll scratch it and then covering it up with crappy paint. So in summery, keep your chin up, you CAN solve this. It's up to you. If you choose more natural products you can get rid of dry skin! You can do it.