Aromatization is a process that occurs naturally in the body to convert testosterone into estrogen. The reason for the name, which sounds more like it would deal with scents, is because the enzyme aromatase performs the conversion. Aromatization mostly occurs in the male body, but can occur in females, and occurs naturally, whether from aging or to balance out a large testosterone boost from anabolic steroids. If this occurs as a result of steroid use, the body can undergo drastic and damaging changes, whereas natural aromatization causes the male body to slightly decline in muscle mass and strength over a long period of time as a result of aging but has many benefits for younger people, such as glucose optimization and better cholesterol management.
The human body is inclined to gravitate toward balance by use of a function called homeostasis. Homeostasis keeps the body in an average range in terms of temperature, hormones, mass and many other factors. This is why aromatase exists. Its primary purpose is not to turn testosterone into estrogen; rather it more commonly synthesizes cholesterol and fats.
Testosterone is not a hormone made in great quantity but is created at an average of 7 mg a day. Most anabolic steroids pump a much higher amount of testosterone into the body, typically from 100 to several hundred milligrams, which makes the human system more susceptible to aromatization. This is because, at higher amounts of imbalance, the homeostasis system is more inclined to balance whatever is causing the problem.
The amount of testosterone affected by aromatase depends on the overall amount of aromatase in the body. Higher levels will convert more testosterone but, eventually, most steroid users will be affected by aromatization. A large amount of testosterone is entering the body, much more than what is naturally produced, so a relatively large amount of estrogen will be created from the conversion.
Estrogen in the male body is not detrimental; it is actually quite helpful. Estrogen is able to increase bone mass; is naturally a steroid and, thus, can lead to added muscle mass when combined with testosterone; and regulates libido. This hormone also aids in recovering from exercise because it helps the body use glucose.
Problems occur when estrogen is too high in the body. Aromatization in the presence of high testosterone levels, especially people with high levels of aromatase, will develop gynecomastia, cholesterol problems and decreased immunity, among other effects. In natural amounts, aromatase will help the body by producing healthy amounts of estrogen, and the amount of testosterone converted into estrogen is usually slight. Any negative effects from estrogen are usually small and occur over the course of many years.