[13][14] Still, "it is prudent not to start testosterone therapy in men with diabetes solely for the purpose of improving metabolic control if they show no signs and symptoms of hypogonadism.
[17] On January 31, 2014, reports of strokes, heart attacks, and deaths in men taking testosterone-replacement led the FDA to announce that it would be investigating this issue.
[21] Concerns have been raised that testosterone was being widely marketed without the benefit of data on efficacy and safety from large randomized controlled trials.
[22] As a result of the "potential for adverse cardiovascular outcomes", the FDA announced, in September 2014, a review of the appropriateness and safety of testosterone replacement therapy.
[26][27] Other significant adverse effects of testosterone supplementation include acceleration of pre-existing prostate cancer growth in individuals who have undergone androgen deprivation; increased hematocrit, which can require venipuncture in order to treat; and, exacerbation of sleep apnea.
[28] A 2014 review said there was some evidence men with certain comorbidities may be at risk of adverse effects including sleep apnoea, metabolic syndrome and cardiovascular disease.
[33] As of September 2014, testosterone replacement therapy has been under review for appropriateness and safety by the Food and Drug Administration due to the "potential for adverse cardiovascular outcomes".