The relationship between dermatologists and cosmetic chemists is interesting. While I can’t speak for dermatologists, from a cosmetic chemist perspective I respect dermatologists for their knowledge about skin and hair biology and also their ability to treat and improve skin conditions. But as bright as dermatologists can be, I’ve seen plenty of instances when they were fooled by cosmetic product marketing just like everyone else. Take this video about hair advice from the AAD for example.[youtuber youtube=’http://www.youtube.com/watch?v=4bw7nMXW36I’]
For the most part, the advice they offer is excellent and spot on. Particularly the point that price does not reflect the performance of shampoos and the need to use a conditioner after every shampooing. But they make three points which I contend are not supported by evidence.
First, they say that you should choose your shampoo based on your type of hair. The reality is that shampoos from the same brand rarely perform noticeably better on one type of hair versus another. Sure, there are minor tweaks to the formula so that companies can make legitimately claim that the formulas are “designed” for different hair types, but if you tested the formulas side-by-side and blinded, you would be hard pressed to find performance differences.
This isn’t always true so you should check the LOIs of the shampoo. But if the LOIs are essentially the same, you will be unlikely to notice ANY difference in performance between a product for color treated hair or one for fine, thin hair.
Increases hair strength
Another claim they make is that conditioners can help increase hair strength. While I know that companies make hair strengthening claims, the reality is that conditioners do very little to increase hair strength. What they do is to improve the slickness of the surface so when a comb goes through the hair it slides by and doesn’t break the fiber. If you did a fiber break analysis of a hair treated with conditioner versus an untreated control, it is unlikely that any conditioner is going to significantly increase the strength of hair.
Finally, the video makes a claim that swimmers should use special “swimmer’s shampoo”. I don’t think this is really necessary as any shampoo will work well enough to remove the chlorine from your hair. There is little to no evidence that a special “swimmer’s shampoo” works any better.
While I’ve spent a lot of time on the criticisms of this video, I wanted to end by repeating that overall, I think they did an excellent job. This is very good advice for how to take care of your hair. I just wish in the future the AAD might have a cosmetic chemist review the script as these claims could have easily been modified to better reflect reality.