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.