The gains made by athletes in uncontrolled observations have been much more impressive. Weight gains of thirty or forty pounds, coupled with thirty percent increases in strength, are not unusual. Such case studies lack credibility because of the absence of scientific controls. However, it would be foolish to completely disregard such observations because the "subjects" have been highly trained and motivated see the articles on pharmacology of sport and sports medicine in the countries of the former Soviet Union for more information on anabolic steroids.
Boys with too little androstenedione may fail to develop the sexual characteristics associated with puberty, including pubic and body hair, growth of the sexual organs and deepening of the voice. Similarly, girls may fail to start their periods and may not undergo many of the changes usually seen in puberty. In addition, if a male foetus has too little androstenedione, he may be born with abnormal genitalia. Too little androstenedione in later life would cause the same changes for both men and women as too little testosterone and oestrogen.