Male Infertility and Acetyl-L-Carnitine

The researchers chose 60 infertile men between the ages of 20 and 40 to take a combination of L-carnitine and L-acetyl-carnitine or a placebo for six months. The group, led by Dr. Andrea Lenzi, reported in the medical journal Fertility and Sterility, that two months after the patients had completed their course of supplements, the men who had taken L-carnitine and L-acetyl-carnitine had increased sperm concentration and movement. The most significant improvements in sperm motility, both forward and total, were observed in men who had the lowest levels of moving sperm when the study began.

The researchers noted that four spontaneous pregnancies were achieved during the study by men who had taken the combination therapy. "Combined treatment with L-carnitine and L-acetyl-carnitine was effective in increasing sperm motility, especially in groups with lower baseline levels (of moving sperm)," they concluded.