L-Carnitine and L-Acetylcarnitine, Beneficial in Men with Idiopathic Oligoasthenozoospermia

Table of Content


Oxidative stress, sperm apoptosis and DNA damage are significant causes of male infertility. L-carnitine (LC) plays a key role in the oxidation of long-chain fatty acid. Its active form, L-acetylcarnitine (ALC) has antioxidant property; protecting the mitochondria from metabolic toxins. Several studies have demonstrated the beneficial effects of carnitine on sperm parameters in idiopathic oligoasthenozoospermia in men. LC is known to increase the sperm concentration and motility.


To evaluate the efficacy of a combined formulation of LC and ALC along with micronutrients on the sperm and seminal biochemical parameters in men with idiopathic oligoasthenozoospermia, who failed to impregnate their partners over the past 12 months.

Patient Profile

  • Men with a mean age of 31.5 years
  • Diagnosed with idiopathic oligoasthenozoospermia and failed to impregnate their wives over the past 12 months
  • One semen analysis which demonstrated either
    • total sperm count <15 million per ml
    • progressive motility <32%
    • normal viscosity and normal leucocytes count <1x106/ml
    • total ejaculate volume 1 ml
    • sperm vitality <58% live
    • normal sperm morphology <4%


Study Design

Prospective, randomized, double-blind, placebo-controlled trial.

Treatment Strategy

  • Total cohort of 175 men
  • 125 received the test formulation and 50 received placebo twice daily for 6 months
  • Test formulation consisted of 1 g LC, 0.5 g ALC, 0.725 g fumarate, 1 g fructose, 50 mg citric acid, 10 mg zinc, 20 mg coenzyme Q10, 50 µg selenium, 90 mg vitamin C, 200 µg folic acid and 1.5 µg vitamin B12
  • All underwent semen analyses at month 3 (T3) and month 6 (T6) after treatment initiation


  • Sperm volume
  • Progressive motility
  • Sperm vitality
  • Sperm DNA fragmentation index
  • Seminal LC and α-glucosidase concentration


  • There was significant improvement in the sperm volume (p=0.001), progressive sperm motility (p<0.001) and vitality (p=0.002) after the therapy with the test formulation at T3 and T6 as shown in figure 1.
  • The therapy resulted in a significant reduction in the DFI (p<0.001) as shown in figure 1.
Figure 1. Sperm parameters at baseline, T3 and T6

  • There were significant increases in the seminal carnitine (p<0.001) and α-glucosidase (p=0.002) levels after 6 months of therapy as shown in figure 2.
Figure 2. Changes in seminal carnitine and α-glucosidase levels at month 6

  • Increased concentrations of seminal carnitine and glucosidase correlated positively with improved progressive sperm motility
  • Reduced DFI was good predictor of progressive sperm motility >10%
  • Simultaneous changes in sperm vitality and DFI after 6 months of therapy had the highest accuracy of detecting individuals with sperm motility 10% (p<0.001)
  • Decrease in DFI independently predicted sperm motility 10% (odds ratio 1.106; p=0.034)


  • The formulation with L-carnitine (LC) and its active form L-acetylcarnitine exerted beneficial effects on the sperm motility, vitality and DNA fragmentation in men with idiopathic oligoasthenozoospermia
  • Seminal LC concentrations play a vital role in maintaining the male fertility
  • Combining metabolic and micronutritive factors is beneficial in male infertility

Andrologia. 2019 Mar 15:e13267. Doi: 10.1111/and.13267.