Sustanon contains, 100/ml short-acting Testosterone Propionate, 100mg/ml of Testosterone Phenylpropionate, 100mg/ml of Testosterone Isocaproate and 150mg of Testosterone Decanoate. The first, testosterone propionate, is short-acting and gives Sustanon a quick onset of action in a steroid cycle. The other esters are medium to long-acting. Testosterone is responsible for promoting health and well-being through enhanced libido, energy, immunity, increased fat loss, gaining and maintaining lean muscle mass, preventing Osteoporosis (loss of bone density) and possible protection against heart disease Sustanon has a release time of between 1-12 days. It is typically injected twice every week, though some users opt for a higher injection frequency of three times per week. Average dosages are 250mg-1000+mg per week.