Farzad Roshanzamir - Noncommunicable DiseasesResearch Center, FasaUniversity of Medical Sciences,Fasa, Iran..Department of ClinicalNutrition, School of Nutritionand Food Science, IsfahanUniversity of Medical Sciences,Isfahan, Iran
Seyyed Morteza Safavi - Department of ClinicalNutrition, School of Nutritionand Food Science, IsfahanUniversity of Medical Sciences,Isfahan, Iran

Background: D-Aspartic acid (D-Asp) is in invertebrate and vertebrateneuroendocrine tissues, where it carries out important physiological functions.Recently, it has been reported that D-Asp is involved in the synthesis and release oftestosterone and is assumed can be used as a testosterone booster for infertile men,and by athletes to increase muscle mass and strength.Objective: The aim of this review is to summarize available evidence related to theeffects of D-Asp on serum testosterone levels.Materials and Methods: We conducted a systematic review of all type studies,which evaluated the effect of the D-Asp on blood testosterone including publishedpapers until October 2015, using PubMed, ISI Web of Science, ProQuest andScopus database.Results: With 396 retrieved records, 23 animal studies and 4 human studies wereincluded. In vivo and in vitro animal studies revealed the effect of D-Asp dependingon species, sex and organ-specific. Our results showed that exogenous D-Aspenhances testosterone levels in male animal’s studies, whereas studies in humanyielded inconsistent results. The evidence for this association in man is still sparse,mostly because of limited number and poor quality studies.Conclusion: There is an urgent need for more and well-designed human clinicaltrials with larger sample sizes and longer duration to investigate putative effects ofD-Asp on testosterone concentrations

D-Aspartic acid, Testosterone, Systematic review