I saw this posted over at AM. I find it very interesting that the negative side effects many atribute to elivated test levels, are very likely caused by increased estrogen. makes perfect sense to me, why else would women act like violent nonsensicle beasts 98% of the time
Numerous studies have investigated the effect of exogenous AAS on males and females, and most all report an increase in aggressiveness and alteration of behavior. Although an apparent link exists between exogenous testosterone use and aggression, particularly in males, recent literature has reported that estrogen, and not testosterone, may be responsible (Ogawa, et al., 1995). This theory has been studied because testosterone is aromatized to estrogen, which in turn can have a direct effect on the brain. Evidence to support this theory comes from two studies—one conducted with mice and one with humans. In the first study, behavioral results on the loss of functional estrogen receptors in male estrogen receptor knockout mice were investigated (Ogawa et al., 1995). The study showed that the lack of estrogen receptors in the central nervous system modified male emotional behavior, thereby making the mice less susceptible to steroid-induced aggression. This indicates the importance of estrogen receptors for increasing aggression following AAS treatment.
A double-blind, placebo-controlled, three-month study was conducted to investigate the effects on behavior and aggression of depo-testosterone or estrogen in hypogonadal boys or girls (Finkelstein et al., 1995). The results were evaluated using the Olweus Multifaceted Aggression Inventory. At low doses, aggressive responses and actual physical aggression against peers was significantly increased only for girls. At mid-dose levels, the scores for girls significantly increased for these same traits. In addition, both boys and girls had increased physical aggression toward adults. At the highest dose, physical aggression against peers was increased only for boys. The results suggest that steroids can influence aggressive behavior in adolescents. In addition, because the girls showed earlier and greater increases in aggression than boys, it is possible that excessive estrogen plays a major role in the development of aggression and that testosterone may contribute to this response through its conversion to estrogen. While circulating levels of estrogen in males is normally low, any increase as seen following AAS use may have profound effects. Because estrogen in the plasma crosses the blood-brain barrier, increased activation as a result of a higher circulating estrogen level may contribute to the aggressiveness and other behavioral changes seen in males following AAS use.
Finkelstein J., Susman E., Chinchilli V., et al. (1995). Testosterone or conjugated estrogen cause increases in aggressive behavior in hypogonadal boys or girls (abstract). 77th Annual Meeting of the Endrocrine Society.
Ogawa S., Luban D., Korach K., et al. (1995). Behavioral characteristics of transgenic estrogen receptor knockout male mice: Sexual aggressive and open-field behaviors (abstract). 77th Annual Meeting of the Endrocrine Society.