Carnitines and male infertility

  • A Agarwal
    Correspondence: Tel: +1 216 4449485; Fax: +1 216 4456049
    Centre for Advanced Research in Human Reproduction, Infertility, and Sexual Function, Glickman Urological Institute and Department of Obstetrics and Gynecology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk A19.1, Cleveland, OH 44195, USA
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  • Tamer M Said
    Centre for Advanced Research in Human Reproduction, Infertility, and Sexual Function, Glickman Urological Institute and Department of Obstetrics and Gynecology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk A19.1, Cleveland, OH 44195, USA
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      L-Carnitine (LC) and acetyl-L-carnitine (ALC) are highly concentrated in the epididymis and play a crucial role in sperm metabolism and maturation. They are related to sperm motility and have antioxidant properties. The objective of this review is to summarize the multiple roles played by LC and ALC in male reproduction, and to highlight their limitations as well as their benefits in the treatment of male infertility. A variety of studies support the conclusion that LC and/or ALC at total daily amounts of at least 3 g per day can significantly improve both sperm concentration and total sperm counts among men with astheno- or oligoasthenozoospermia. Although many clinical trials have demonstrated the beneficial effects of LC and ALC in selected cases of male infertility, the majority of these studies suffer from a lack of placebo-controlled, double blind design, making it difficult to reach a definite conclusion. Additional, well-designed studies are necessary to further validate the use of carnitines in the treatment of patients with male infertility, specifically in men with poor semen quality.



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      Dr Ashok Agarwal is the Director of Research at the Centre for Advanced Research in Human Reproduction, Infertility, and Sexual Function, and the Director of the Clinical Andrology Laboratory and Reproductive Tissue Bank. He holds these positions at The Cleveland Clinic Foundation, Ohio, USA, where he has been a full staff member in the Glickman Urological Institute, Departments of Obstetrics–Gynecology, Anatomic Pathology, and Immunology since 1993. Dr Agarwal has published extensively in different areas of Andrology. His current research interests include the role of oxidative stress, DNA integrity, and apoptosis in the pathophysiology of male and female reproduction, cryopreservation of spermatozoa in patients with cancer, epididymal physiology, and pathophysiology of sexual dysfunction.