The use of anabolic steroids such as Winstrol may be associated with serious adverse reactions, many of which are dose related. Patients should be placed on the lowest possible effective dose. Medications that may interact with Winstrol include anticoagulants (blood thinners), insulin , or an oral diabetes medicine. Tell your doctor all medications you are taking. Winstrol is known to cause birth defects in a fetus. Do not take this medication if you are pregnant or could become pregnant during treatment. It is not known whether Winstrol is excreted in human milk. Many drugs are excreted in human milk and there is the potential for adverse reactions in nursing infants from anabolic steroids. Consult your doctor before breastfeeding.