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.
1 Estrogen also makes women store fat more in the subcutaneous areas (fat just under the skin and in the arms and legs), versus the deep belly fat in the middle of the body.  Estrogen may have a different impact on deep abdominal fat, either not impacting it at all or speeding its release.