Progestins are steroid hormones that are typically prescribed to postpone heat cycles or alleviate false pregnancies in female dogs and treat benign prostatic hypertrophy in male dogs. They may also be used for some types of skin problems or to modify aggressive behavior. Megestrol acetate and medroxyprogesterone are the most commonly used progestins in dogs. Potential side effects include increased thirst and appetite, behavioral changes, mammary gland enlargement, and an increased likelihood of developing diabetes mellitus, acromegaly (a hormonal disease that causes enlargement of the head), Cushing’s disease, uterine infection (pyometra), reproductive disorders, and some types of cancer.
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.