Article Index

Written by Dan Gwartney, M.D.
04 May 2009

Anabolic Steroids and Sexual Behavior

 

Through the course of history and across the span of evolution, few things hold the interest of individuals as much as sex.1 Though individuals may survive without succumbing to the desires of the flesh, for the species, it’s essential. The drive for sexual intercourse is hard-wired into nearly every being.

 Back to Basics
Sexual behavior is easily studied in animals. Scientists are beginning to understand, down to the level of hormones, receptors, genes and neurotransmitters, how sexual behavior is regulated in humble creatures, such as rats.2 It’s a simple matter to inject a female rat with hormones that place her in estrus, a physiologic state which causes her to become attractive to male rats and receptive to sexual intercourse. For the male rat, it’s even easier; male rats will respond to the physical and behavioral cues of the female. Never satisfied to merely observe the normal interaction between rats, scientists have performed a vast number of interventions on rats and other animals to determine the basis for their sexual behavior. These interventions range from simple to drastic, including brain surgery and castration (surgical removal of the testicles).
Much to the chagrin of male rats everywhere, castration allows for a clear picture of the effect of androgens upon male sexual behavior. Castration eliminates most sexual response in male rats and other species, rendering them impotent as well, which is why many emperors and sheiks had eunuchs (castrated men) serving as guards and servants to their wives and mistresses.
Scientists learned it’s possible to restore androgen levels through the use of testosterone, restoring sexual behavior and function.3,4 The restoration of sexual behavior and function through the use of testosterone replacement therapy is also used in human clinical practice.5 Men suffering from a failing libido or erectile difficulty are placed on testosterone (injections, patches or creams), though the introduction of Viagra and similar drugs has reduced the demand. Testosterone replacement therapy has restored the vitality and libido of many aging men.
With the notoriety of anabolic steroids and their close chemical resemblance to testosterone, scientists investigated the effects of these drugs upon sexual behavior in castrated rats. Rather than getting a clear cut answer, as might be expected from these powerful androgens, a full look at the data suggests that one cannot simply assume that all steroids will affect sexual behavior in a manner similar to testosterone.
Sexual behavior is a complex series of physical, psychological and social cues and responses designed to combine the act of mating (sex) with the best reproductive environment.2,6,7 This is particularly evident in lower animal forms, where the female is only receptive to mating during the time of her ovulation (releasing an ovum or egg cell to be fertilized by sperm). Most people are familiar with this phenomenon through their experience with pet dogs or cats that “go into heat.” Suddenly, every unpenned mutt or stray tomcat in the neighborhood shows up ready to mount, eyes rolling and tongue lolling for his chance at siring the next litter.

Public Erections are Generally Discouraged
With humans, the process is more complicated, discounting public examples of debauchery such as Mardi Gras or fraternity parties. Sexual behavior includes several phases, including: desire, arousal, intercourse and latency. Desire refers to the underlying yearning for a sexual encounter; no specific time, place or person; just a desire for sex. For people in a monogamous relationship, desire is conditioned to refer to a single person— the significant other. Arousal is more specific and immediate. Arousal refers to wanting sex immediately with the subject of the aroused person’s focus. This may relate to a promising date eating across the table or an actress in a television show. In addition to mental and emotional changes, physical changes also are evident at this point, including flushing of the skin, dilated pupils and penile erection.

Again, people are conditioned to respond to social cues and the environment. It’s considered funny or excusable if an adolescent boy becomes excited in the presence of girls and women or while climbing the rope in gym class, but for adult men, public erections are generally discouraged. Intercourse refers to the sexual act, which ranges from complex rituals to hurried encounters. Latency is the amount of time elapsing between the completion of one sexual act until the male achieves his next state of sexual readiness.
Referring back to animal studies, it was clear that testosterone levels correlated with all phases of sexual behavior. Castration resulted in very little curiosity in or attraction to sexually receptive females, markedly reduced attempts at intercourse and long latency periods.3,4 Providing high doses of testosterone increased sexual behavior above that of normal rats.8 This effect is seen in humans— male and female, comparing people with low testosterone to normal adults to adolescents.5,9-12 Obviously, there are many exceptions to this general rule, as humans modify their behavior to conform to public expectations, religious beliefs and social mores.13