I'm looking for a medical opinion on Hair Skin and Nails sold through ItWorks. Preferably a dermatologist' opinion?

OK. In reviewing the ingredients, it looks like it should be helpful to hair health, helping hair growth, thickening and texture over the long term. There is good science behind many of the ingredients, medical and herbal, but not a significant set of studies for the actual product. Downside risk is very small from use.