Many steels add to the iron-steel mix other metals that give the entire substance desirable properties such as strength, heat resistance, or flexibility. Steel is considered a mixture rather than a compound because the iron does not chemically bond with the carbon and other components.
Some of estrogen's effects include: 1  Increasing serotonin, and the number of serotonin receptors in the brain. 2  Modifying the production and the effects of endorphins, the feel-good chemicals in the brain. 3  Protecting nerves from damage, and possibly stimulating nerve growth.
Estrogen helps your skin retain moisture and protects skin from damage, so producing less estrogen can alter your skin. Replacing the estrogen through HRT can make skin more radiant. According to studies, long-term use of HRT after menopause left women with more elastic skin and less harsh wrinkles.