Cyclomethicone and dimethicone are silicone compounds that are added to skincare products to help them glide smoothly over your skin and deliver a silky feeling. Because they’re silicone based, they may also fill in fine lines and wrinkles, offering a temporary solution by ‘plumping’ up the outer layer of the skin. Once they’re on the skin, these silicones can also create a barrier which might help the skin retain moisture. However that same barrier may also prevent other ingredients from penetrating the skin, so make sure that if you’re using one of these products, you apply the penetrating ingredients first. Scientists say that these compounds are not hazardous and not toxic, but at the same time may harm the environment.