Last reviewed on RxList 7/2/2015. Winstrol (anabolic steroids) is a synthetic steroid, similar to testosterone, used in the treatment of hereditary angioedema, which causes episodes of swelling of the face, extremities, genitals, bowel wall, and throat.Winstrol may decrease the frequency and severity of these attacks.ast reviewed on RxList 7/2/2015. Winstrol (anabolic steroids) is a synthetic steroid, similar to testosterone, used in the treatment of hereditary angioedema, which causes episodes of swelling of the face, extremities, genitals, bowel wall, and throat. Winstrol may decrease the frequency and severity of these attacks.