You should read the ingredients of all your makeup and medications. Anything you put on your face or body. Your skin being an organ, you need to treat it right. Some things are allot worse to put on your skin than others. Below are 4 that you should be ware of.

Alkyl-phenol Ethoxylades
Found in shampoo and bubble bath.

Alpha Hydroxy Acid
this actually destroys skin cells and leaves skin more susceptible to damage from the environment, pollution and it causes skin cancer. This actually ends up aging skin whereas it advertises that it makes skin look and feel younger. Found in anti-aging facial creams and lotions.Aluminum
this causes central nervous system damage and it has recently been linked to Alzheimers. Found in antiperspirant deodorants.

Ammonium Glycolate
this is what is called a photosensitizer and has the potential to increase risk of sunburn and skin cancer by intensifying UV exposures in deep skin layers. This can start an immune system response that includes itching, burning, scaling, hives, and blistering of skin. This can also alters the skins’ structure, allowing other chemicals to penetrate deeper into the skin, which will cause the amounts of other chemicals that reach the bloodstream to increase. Found in most body products like lotions etc.

These by no means are the only ones. But it's a good start. Start with what you can managed then we will get into all the chemicals you should eliminate. You want to strive for as close to nature as you can. Natural skin care goes much deeper than just makeup.