PIP: Caution should be practiced with oral contraceptives in dope control of anabolic steroids. Research in the Netherlands has shown that there are problems in the area of dope control of anabolic steroids: 1) when the oral contraceptive norethisterone is introduced, it changes within the body to a small amount of 19-norandrosterone, the primary metabolite of the anabolic steroid 19-nortetosterone. As a result, this transformation makes it hard to detect the origin of 19-norandrosterone. The derivatives of the main metabolite of norethisterone and methenolone have similar retention times and mass fragments, making screening difficult. The main metabolite of norethisterone also interferes with methenolone, another anabolic steroid. However, the latter problem is a solvable one. The derivatisation process used to confirm the use of methenolone is described. More testing of urine samples after sporting events will be presented in a successive report. A gas chromatography-mass spectrometry process for detecting and confirming metabolites is recommended by the Medical Commission of the International Committee.