Many practitioners of alternative and integrative medicine are familiar with the essential roles L-carnitine plays in energy production, oxidative stress, and glucose metabolism.1 L-carnitine has been shown in animal models to stabilize mitochondrial membranes, increase energy delivered to organelles, and protect against cellular apoptotic death.2 Acetyl L-carnitine is thought to provide additional clinical applications. It may support mitochondrial function, memory, and antioxidant status.*3,4,5 It may also have a structural role in peripheral and central nervous tissue.*6 Perhaps less familiar, is that L- carnitine supplementation has been used to support glucose metabolism* and some research has shown that L-carnitine insufficiency is even a contributing factor to related health status.7
One study showed that a subset of women seeking hormone balance had lower levels of serum L-carnitine and that decrease was correlated to changes in sex hormones and insulin.8 Even more specifically, a double-blind, placebo-controlled, parallel-group study, conducted in Egypt assessed the effectiveness of L-carnitine on the occurrence of ovulation and pregnancy in women seeking healthy fertility.*9 Women were randomly assigned to one of two groups. Group A (n=85) received 250 mg of a conventional agent intended for ovulation from day 3 until day 7 of the menstrual cycle, plus L-carnitine 3 grams per day. Group B (n=85) received 250 mg of the same conventional agent with placebo.
The combination of L-carnitine and the conventional agent significantly improved both the ovulation rates (64.4% with L-carnitine vs 17.4% with placebo) and the cumulative pregnancy rates (51.5% vs 5.8%).* In addition, there was a significantly higher level of serum progesterone in the luteal phase among the L-carnitine and conventional agent group (Group A) compared with the control group (Group B).* There were also additional metabolic benefits in the women in Group A after 12 weeks.*
Pregnancy rates are the name of the game in women taking the common conventional agent used in this study and the results in this study were compelling in this regard. Explanations for this can include:
- An increase in luteal phase progesterone.
- Greater endometrial thickness (Group A =10.1 mm vs Group B =6.8 mm).
- The free radical scavenging effect of L-carnitine and subsequent effects on the endometrial blood flow ultimately supporting healthy endometrial receptivity in the peri-implantation phase.*
- Vanella A et al.Cell Biol Toxicol 2000;16:99-104.
- Pillich R et al. Exp Cell Res 2005;306:1-8.
- Montgomery SA et al. Int Clin Psychopharmacol. 2003;18(2):61-71.
- Malaguarnera M et al. Metab Brain Dis. 2011;26(4):281-9.
- Pettegrew JW et al. Neurobiol Aging. 1995 Jan-Feb;16(1):1–4.
- Vivoli E et al. Neuroscience. 2010 Jun 2;167(4):1168-74.
- Ringseis R et al. Eur J Nutr 2012;51(1):1-18.
- Fenkci S et al. Hum Reprod 2008;23 (7):1602-6.
- Ismail A et al. European J Obstetrics and Gynecology and Reproductive Biology. 2014; 180: 148-52.