The mixture of the testosterones are time-released to provide an immediate effect while still remaining active in the body for up to a month. As with other testosterones, Sustanon is an androgenic steroid with a pronounced anabolic effect. Therefore, athletes commonly use Sustanon to put on mass and size while increasing strength. However, unlike other testosterone compounds such as cypionate and enanthate, the use of Sustanon leads to less water retention and estrogenic side effects. This characteristic is extremely beneficial to bodybuilders who suffer from gynecomastia yet still seek the powerful anabolic effect of an injectable testosterone. The decreased water retention also makes Sustanon a desirable steroid for bodybuilders and athletes interested in cutting up or building a solid foundation of quality mass. Dosages of Sustanon range from 250 mg every other week, up to 2000 mg or more per week. These dosages seem to be the extremes. A more common dosage would range from 250 mg to 1000 mg per week. Although Sustanon remains active for up to a month, injections should be taken at least once a week to keep testosterone levels stable.

A steroid novice can expect to gain about 20 pounds within a couple of months by using only 250 mg of Sustanon a week. More advanced athletes will obviously need higher dosages to obtain the desired effect. Sustanon is a fairly safe steroid, but in high dosages, some athletes may experience side effects due to an elevated estrogen level. With dosages exceeding 1000 mg a week, it is probably wise to use an antiestrogen such as Zymoplex (tamoxifen citrate) or Proviron (mesterolone). The use of Sustanon will suppress natural testosterone production, so the use of HCG (human chorionic gonadotropin) or Clomid (clomiphene citrate) may be appropriate at the end of a cycle. Sustanon 250 is a good base steroid to use in a stack. Athletes interested in rapid size and strength gains find that Sustanon stacks extremely well with orals such as   Oxydrol (oxymetholone) and Dianabol (methandrostenlone). On the other hand, Sustanon also stacks well with Trenabol Depot (trenbolone hexahydrobencylcarbonate), Mastabol (drostanolone propionate), and Winstrol (stanozolol) for athletes seeking the hard, ripped look. Sustanon 250 is quite abundant on the US black market.

Sustanon will do exactly what other forms of testosterone will do:

Testosterone will cause both muscle growth as well as fat loss. It sends a message to muscle cells to store more contractile protein (called actin and myosin), thus making your muscles grow. It also protects your muscles from catabolic (muscle wasting) glucocorticoid hormones. Thus it is often said that testosterone is not only anabolic, but it is strongly catabolic. Not only does it cause an increase in size of the muscle fibbers (hyperfascia) but it also can change the appearance and the actual number of muscle fibbers (Hyperplasia). Testosterone has the ability to increase erythropoiesis (red blood cell production) in your kidneys, and a higher Red Blood Cell (RBC) count may improve endurance by producing more highly oxygenated blood. More RBCs can also improve recovery from strenuous physical activity. Aggression levels often rise dramatically with the use of any exogenous testosterone . Testosterone improves muscle contraction by increasing the number of motor neutrons in muscle and improves neuromuscular transmission. It also promotes glycogen synthesis

And, since Sustanon is simply a form of (well actually 4 forms of) testosterone, the more you take, the bigger you get... This is true of Sustanon as well as for every form of testosterone, up to a point.

Unfortunately, Sustanon will also do all of the bad things that any form of testosterone is known for:

It will convert to the female hormone estrogen (via a mechanism known as aromatization) by the (you guessed it) aromatize enzyme. Excessive estrogen can lead to unwanted side effects, such as acne, the growth of breast tissue (gynecomastia), fat gain and reduced fat breakdown, loss of sex drive, testicular shrinkage and water retention. Water retention can increase blood pressure weakening blood vessels over time. Unfortunately, this isn´t all it does& it can also interact with the 5 alpha-reductase enzyme. This interaction converts the testosterone to Dihydro-testosterone (DHT), a more androgenic form of the parent hormone. DHT has a high binding affinity to the tissues of the scalp resulting in hair loss in loss in users who suffer from male pattern baldness. DHT can affect the prostate as well, making it larger. This swelling can cause the gland to press against the bladder causing urinary problems. Drugs called 5alpha-reductase inhibitors can prevent these symptoms without blocking testosterone´s anabolic effects.(8) Higher dosages of test can also negatively impact cholesterol, lowering HDL(9). Testosterone is probably the safest steroid around, but it can´t be taken lightly, and Sustanon is no different.