The testosterone drug Androgel is meant to treat patients who have been diagnosed with an androgen deficiency. There have been serious side effects linked to Androgel and other low testosterone drugs that potentially outweigh any benefit the treatments may provide. The most serious side effects reportedly linked to Androgel include, stroke, heart attack and, in unfortunate cases, death. While cardiovascular problems occur in many men, there have been studies that indicate there is an increased risk in men who take low testosterone medications like Androgel. Less serious side effects can include depression, decrease in muscle mass, lowered sexual desire, and tiredness.