The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.     
Chemical Names: 4-androsten-3-one-17beta-ol 17beta-hydroxy-a ndrost-4-en-3-one
Estrogenic Activity: moderate
Testosterone cypionate is a slow-acting injectable ester of the basic male androgen testosterone. Testosterone is the principle anabolic hormone in men as well , and is the base of comparasion by which all other anabolic/androgenic steroids are adjudicated. Each testosterone injectables, testosterone cypionate is extremely preferred by athletes for its efficiency to promote strong gains in muscle mass and force.
Testosterone cypionate is obtainable in select human and veterinary drug marketplaces. structure and dose can diverge by country and manufacturer, but usually has 50 mg/ml, 100 mg/ml, 125 mg/ml, or 200 mg/ml of steroid solubled in oil.
Average dose: 250-1000 milligrams per week
The half-life of testosterone cypionate is about eight days after shot.
Side Effects (Estrogenic):
Raised estrogen levels could induce side effects such raised water retention, body fat gain or gynecomastia. Testosterone is regarded a moderate estrogenic steroid. An anti-estrogen such as clomiphen citrate or tamoxifen citrate may represent required prevention of estrogenic side effects.
Side Effects (Androgenic):
Testosterone is the basic male androgen, liable for maintaining secondary male sexual characteristic.
There`re androgenic side effects inclusive oily skin, acne, a body/facial hair growth.
Side Effects (Hepatotoxicity):
Testosterone doesn`t have hepatotoxic action; liver toxicity is improbable.
Muscles are important components of the human body. They are necessary for our harmony development and hight quality life. Elastic muscles make your body not only hard, powerful, but also beautiful. Athletes and professional bodybuilders decide to buy testosterone cypionate after they find out what great effects it brings to their body. But before you start using steroids for sale it you need to understand the importance of some special techniques known as post cycle therapy to avoid some unwanted side effects and to avoid any damage to your system.