Statins May Cause Libido Changes by Lowering Male Sex Hormones. Mustafa Aparci, Turgay Ebiloglu, Sercan Okutucu, Zafer Isilak, Ender Oral. Dept.of Cardiology Kasimpasa Military Hospital, Istanbul, Turkey; Dept. of Urology, Etimesgut Military Hospital, Ankara, Turkey; Dept. of Cardiology, Memorial Hospital, Ankara, Turkey; Dept. of Cardiology, Haydarpasa Training Hospital, Istanbul, Turkey. Background: Unfavorable effects of statins on serum levels of testosterone and also on male characteristics are the novel side effects which have been recently focused. The most frequent manifestations of reduced levels of testosterone may lead complaints about erectile dysfunction and reduced libido. Case: The patient is a 35 years old male with family history of atherosclerotic coronary artery disease (CAD). He had been diagnosed as CAD by a Multi-sliced Computerized Tomography Angiography upon the dyspnea on effort a few years ago and prescribed acetylsalicylic acid 100 mg/day, and atorvastatin 20 mg/day. He was admitted to the urology service with the complaint of fatigue, reduced libido and sexual reluctance for several months. Laboratory results of the patient were presented as following. When he was under statin therapy, his serum level of testosterone was as 270.6 and 273.0 ng/ml; the lowest levels of normal range (270-1070 ng/ml); during 6 and 4 months ago respectively. Then he tapered statin therapy to every other day protocol for a month and then stopped taking it. Thereafter serum levels of Testosterone elevated to 306.8 ng/ml and 394.7 ng/ml, respectively. However serum level of LDL cholesterol increased from 102 and 130 mg/dl to 177 and 205 mg/dl simultaneous with the periods of being under and stopping the statin therapy, respectively. Just following the interruption of statin, we curiously observed that the serum levels of FSH, LH, and prolactin elevated from 1,66 mIU/mL, 1,15 mIU/mL, and 5,94 ng/mL to 1,81 mIU/mL, 1.72 mIU/mL, and 7.59 ng/mL, respectively. Conclusion: In the conclusion statin therapy and hypothalamicpituitary-gonadal axis should exactly be investigated in patients taking statin therapy and recently presented with the signs and symptoms of libido changes and erectile dysfunction. Since widely usage of statin therapy in daily clinical practice for either primary or secondary prevention of cardiovascular disease will certainly increase the number of subjects with signs and symptoms related with reduced sex hormones.