Why L-Carnitine Isn’t a Fad Fat Burner, But a PCOS Super-Nutrient

Let’s first start out by explaining what L-carnitine is, because it is a bit niche if you aren’t deep into biochemistry or the supplement world! Basically, our livers produce L-carnitine from two essential amino acids, lysine and methionine. It’s also found in many animal foods, including beef, chicken and fish and in supplement form if you are vegetarian, vegan or just don’t find yourself consuming many animal products. 

The main role of L-carnitine in your body is to shuttle long-chain fatty acids across cellular membranes and into your mitochondria for beta oxidation. In other words, it helps transport big fat molecules into the energy hub of your cells, where they can be converted to energy and used to fuel many different processes in your body. This is huge! 

L-carnitine and Fitness

Around 2010, public interest in L-carnitine piqued with the publication of several compelling research studies that highlighted L-carnitine’s tremendous fat-burning potential. Unlike overhyped weight loss supplements, L-carnitine never reached a fever pitch and actually does stand up in clinical research to this day. Athletes and fitness enthusiasts continue to use L-carnitine to improve their energy metabolism and, therefore, achieve their body composition goals.

Yet as researchers and practitioners uncover the major (and largely ignored) metabolic component of polycystic ovarian syndrome (PCOS), L-carnitine has emerged as a supportive supplement in the treatment and management of PCOS. So let’s get into the different ways that L-carnitine specifically helps women with PCOS, from lowering cholesterol to improving ovulation rates. 

L-Carnitine and PCOS

Metabolic Health: 

One recent study explored the effect of taking L-carnitine on clinical markers of women with PCOS. Participants were given 3 g of L-carnitine per day for 3 months and blood samples were taken each morning after fasting overnight to assess their levels of fasting glucose (blood sugar), insulin, triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL), free testosterone, dehydroepiandrosterone (DHEA), and their insulin resistance index (HOMA-IR). The women were also weighed before and after the trial to measure any weight loss and changes in their body mass index (BMI). The results were quite impressive, showing a significant improvement in insulin sensitivity, a decrease in their levels of LDLs, often called the “bad cholesterol”, a lower BMI, and an increase in their levels of HDLs, often referred to as the “good cholesterol” (1). 

These results are important because they indicate that L-carnitine has the ability to normalize metabolic profiles and reduce body fat with consistent use over a surprisingly short amount of time. 

Ovarian Health:

Since L-carnitine protects us from mitochondrial damage and restores energy balance, these benefits also extend to our ovarian structures and processes. For instance, it can be hugely helpful in boosting energy reserves used in folliculogenesis (the formation of ovarian follicles) and oocyte (immature egg) maturation. Therefore, L-carnitine may represent an important strategy to improve the intraovarian environment and increase the probability of pregnancy.

In a double-blinded randomized controlled trial, overweight women with PCOS who were resistant to clomiphene (an FDA-approved drug used to treat infertility) were given either metformin (a drug used to treat high blood sugar and/or diabetes) and L-carnitine or just metformin alone. Researchers found that the group of women taking L-carnitine experienced more regular menstrual cycles, improved ovulation rates, and better pregnancy outcomes than the placebo group (2). Another study looked at the impact of L-carnitine on non overweight women who received IVF and failed to conceive. Although there wasn’t a significant difference in fertilization rates in this study, there was an increase in embryo quality following L-carnitine supplementation, specifically noted on days 3-5 (3). These studies suggest that L-carnitine supplementation could be beneficial for reproductive outcomes in women with PCOS, especially when taken in conjunction with other treatments (4). 

Find it in The Cysters Kit

L-Carnitine is one of the star ingredients in Metabolic Guard, our metabolism-supporting formula designed to help those with hormone and energy concerns feel revitalized and achieve optimal metabolic health. It is one of two formulas found in The Cysters Kit, our new 2-part protocol for PCOS and optimal hormone health. Learn more about these hormone-supporting formulas here.