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 .  Adverse effects may also include minor side-effects such as acne and oily skin, as well as, significant hair loss and/or thinning of the hair, which may be prevented with 5-alpha reductase inhibitors ordinarily used for the treatment of benign prostatic hyperplasia , such as finasteride .  Exogenous testosterone may also cause suppression of spermatogenesis , leading to, in some cases, infertility.  It is recommended that physicians screen for prostate cancer with a digital rectal exam and prostate-specific antigen (PSA) level before starting therapy, and monitor PSA and hematocrit levels closely during therapy. 
In February 2017, American triathlete Beth Gerdes was given a 2-year suspension for presence of ostarine, and American triathlete Lauren Barnett was given a 6-month suspension for the presence of Ostarine. Both triathletes claimed contamination from salt tablet supplements. Lauren Barnett was able to provide tablets and sealed bottle tablets which both tested positive for contamination, thus only the 6-month suspension. The 2-year suspension still stands for Beth Gerdes who provided tablets for testing, but tests showed only low levels of ostarine not high enough to confirm the finding.