Until around two years ago, I was flakey about skincare products, I'd use one product, dump it, find something else, move on. It wasn't until I started on my quest to rid myself naturally of heart disease that I really started think about what goes onto my skin.
Your skin is your biggest organ, and it takes in everything you put on it. Here's the scary part though, any nasties that move through the skin into your blood, bypass your kidneys and liver - the two main organs that filter out nasties that would be there if you'd have eaten them.
So, with this going on, these little nasty chemicals do all sorts of vicious things to you, like mess up your endocrine system and can exacerbate any damaged cells in your body leading to exponential damage.
The great thing is that while there are lots of brands out there that sweep chemical waste up and rebrand it as skincare products, there are also a fantastic bunch of experts who set out with good moral values and promote good, safer items.
The Environmental Working Group have a page (and app for that matter) called Skin Deep which lists so many products and explains the potential toxicity using a traffic light system it's great, mainly because I was never very good at chemistry.