Carnitine is a popular dietary supplement used for energy, exercise performance, weight loss, and all kinds of other benefits. Should you take carnitine, though? What are the benefits of carnitine? Let me explain why I recommend carnitine.
What Is Carnitine?
Carnitine is a compound that helps your body to turn fat into energy. It is a derivative of amino acids. It is made in your liver and kidney. It is stored in your skeletal muscle, brain, heart, and sperm (1).
Carnitine can act as an antioxidant. It can fight free radicals and help to reduce the risk of free radical and DNA damage, and related health issues. It may help to improve heart issues, fatigue, athletic performance, liver and kidney health, and fertility.
Under healthy circumstances, your body is able to make the carnitine it needs. However, some people’s bodies cannot make enough carnitine. In some other cases, the body has a problem transporting enough carnitine into the tissues where it is needed. In some health conditions, including intermittent claudication and angina, we see low levels of carnitine. Certain medications may also lead to low carnitine levels.
Types of Carnitine
There are different types of carnitine. L-carnitine is the most common form seen in your body and in many supplements (1).
Types of carnitine include:
- L-carnitine: This is the most common type of carnitine. It may be beneficial for your heart, liver, and kidney health, fertility, and athletic performance.
- Acetyl L-carnitine: This type of carnitine is also known as ALCAR. It supports your metabolism and your nervous system health. (This is the type I most often recommend.)
- D-carnitine: This form of carnitine is the optical isomer of the mirror image of L-carnitine. It may interfere with the absorption of other types of carnitine and can be toxic.
- L-carnitine L-tartate: This type of carnitine is often used by athletes as it may support recovery and reduce muscle soreness (2).
- Propionyl L-carnitine: This form of carnitine may help to reduce rheumatic pain and may support heart health.
Benefits of Carnitine
Carnitine has a number of possible health benefits. Let’s look at the potential benefits of carnitine one by one.
Carnitine is a key component involved in making energy for your cells. It’s not surprising that one of the main benefits of carnitine is improved energy. Carnitine helps to break down fatty acids to create energy. It also helps to remove waste products from your cells, which also supports cellular function and energy levels. According to a 2022 study published in Progress in Nutrition, L-carnitine supplementation may help to reduce fatigue during exercise (2).
One of the benefits of carnitine is supporting exercise and athletic performance. A 2011 study published in The Journal of Physiology has found that carnitine may support fat-burning and exercise performance (3). Carnitine may also support better blood flow, stamina, and exercise recovery (4, 5). A 2018 study published in Nutrients has found that it may be great for exercise recovery (6).
Heart health is another benefit of carnitine. According to a 2018 research published in Life Sciences, carnitine may help to improve markers of cardiovascular health (7). According to a 2004 review published in the Annals of New York Academy of Sciences and other research, L-carnitine may be beneficial for your heart health (8, 9, 10) It may help to improve circulation and heart health after a heart attack. It may also help to reduce symptoms of heart failure.
A 2007 study published in The Journal of Physiology has found that carnitine may support fuel metabolism in skeletal muscle (11). A 2011 study published in Amino Acids and other research have found that carnitine may help to improve insulin sensitivity and reduce the risk of insulin resistance (12, 13, 14).
Another benefit of carnitine may be good news for your brain. A 2017 study published in Neurochemical Research, L-carnitine may have neuroprotective benefits (15). It may be beneficial for hypoxia-ischemia, traumatic brain injury, Alzheimer’s disease, and other brain health issues.
Carnitine may also be helpful for autism. A 2004 study published in the Journal of Autism and Developmental Disorder has found that carnitine deficiency may be an issue in children with autism (16). A 2011 double-blind, randomized clinical trial published in Medical Science Monitor has found that levocarnitine may be a beneficial treatment option in autism (17). Low carnitine, which is common in autism, may impair the ability to use fatty acids for learning and social development. Supplementation may help
Better blood health, or more specifically, improved red blood cell count, may be another benefit of carnitine. According to a 2001 study published in Blood Purification, carnitine may help to improve the production of red blood cells (18). A 2013 research published in Frontiers in Physiology has also found that it may help to improve the production of red blood cells (19).
Supporting cancer treatment, including chemotherapy, may be another benefit of carnitine. According to a 2018 study published in Molecular Clinical Oncology, carnitine may help to reduce fatigue, weakness, and other symptoms associated with cancer treatment (20). It may also help to decrease the risk of tissue damage associated with chemotherapy.
Liver and Kidney Health
Carnitine may offer some help if you have kidney or liver problems. Your kidneys and liver help to make carnitine. If you are dealing with kidney or liver issues or related organ failure, you may develop carnitine deficiency. According to a 2015 study published in Renal Replacement Therapy and a 2016 study published in the Journal of Clinical Medicine Research, carnitine supplementation may be beneficial in these cases (21, 22).
Finally, carnitine may play a role in male fertility. According to a 2004 study published in Reproductive BioMedicine Online has found that L-carnitine may play a role in sperm metabolism, maturation, and motility (23). According to a 2010 study published in the National Journal of Andrology, carnitine may help to improve sperm motility and the chance of pregnancy (24). A 2011 study published in the Journal of Pakistan Medical Association has also found that L-carnitine may support male fertility (25).
How to Use Carnitine
The best and most commonly used form of carnitine is L-carnitine. The amount and form of supplement you need may depend on your specific goals and conditions. It’s always a good idea to consult with your doctor first.
The best food sources of carnitine include high-quality animal products, including beef, pork, chicken, and codfish. Some plant-based foods, including avocados and asparagus, also contain carnitine, but not that much (1).
Adults who consume a healthy diet, including high-quality animal products, may get 60 to 180 mg of carnitine a day. If you fall into this category, you may not need to take carnitine supplements. However, if you are not meeting your needs from diet or are dealing with health issues, you may need to supplement (1). Higher amounts, as part of a nutrient therapy prescription, are often recommended in a functional medicine practice like mine, to assist those with health conditions that could benefit from increased doses.
Vegans and vegetarians usually only get about 10 to 12 mg from their diet. Thus they are more likely to need supplementation. Athletes may also benefit from L-carnitine supplementation to support their workouts and performance. Some evidence suggests that taking L-carnitine may also support weight loss (26).
The standard dose of L-carnitine is about 600 to 2,500 mg/day. Though this dose is generally safe, again, it’s always best to talk to your doctor before starting any supplement. Start at a lower dose to see how your body reacts. Side effects are rare, though some people may experience some nausea or digestive discomfort taking carnitine (27, 28, 29).
If you want to experience the benefits of carnitine listed in this article, you may benefit from supplementation with L-carnitine. I welcome you to start a functional medicine consultation with me for further personalized guidance to improve your health. You may book your consultation here.
Check out my Histamine Intolerance Course here. Learn on your own time, from anywhere. Get an inside look at the most helpful functional medicine tests for pinpointing imbalances, ways to identify and manage the most common (and sometimes surprising) mast cell triggers, and learn what to eat, what to avoid, and why.