If you test out as deficient in testosterone, or if you have symptoms of low testosterone, you likely want to do something about it. There are definitely over-the-counter supplements designed for this very purpose. ( Alpha Male® and Tribex® are the most potent.) And while effective, they're best used by healthy younger men who want a boost in T levels for bodybuilding purposes. They probably aren't the best choice for men who are clinically low and who've made the choice to undergo what's usually a lifetime commitment to testosterone replacement therapy, or TRT.
Both AndroGel and Axiron can cause the same side effects. Some side effects are mild and will go away on their own after your body gets used to the medicine. One common side effect is skin irritation at the application site. It is very important that those applying the gel are aware of the risk of transferring it to others, as this can cause complications in someone who comes in contact with the product. It is advised that when using the gel, patients wash their hands right away after applying the gel and cover the area with clothing until they are able to take a shower.
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.  The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.  Thus it is the challenge of competition among males of the species that facilitates aggression and violence.  Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.  The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.