Where is L-carnitine? It’s important to note that L-carnitine is naturally produced in the body and obtained through dietary sources like red meat, such as beef, lamb, and pork. Lean cuts of meat generally have higher concentrations of L-carnitine. Chicken and fatty fish like cod, halibut, and salmon provide rich amounts of it, too. Dairy items, cheese and milk, also have many, but less than meat and fish. Veges like avocado and asparagus have relatively higher L-carnitine. Not about food; some people want more of it. L-carnitine supplements may be recommended for the following uses.

Fat metabolism & Weight loss
Perhaps it’s the reason why you check the L-cartinine works. The market for this is increasing due to the need for weight loss. L-cartinine’s primary function is to carry fatty acids, especially long-chain fatty acids, into the mitochondria. As an energy-producing plant, the mitochondria use it and convert it into energy. When our body needs to burn fat for its fuel, mitochondria generate ATP, oxidizing fatty acids.
Some scientific evidence suggests through meta-analysis that people with carnitine consumption lost weight, roughly 1.3 kg on average (1). However, the duration of consumption revealed that the magnitude of weight loss resulting from carnitine supplementation significantly decreased over time. Another review reported that L-carnitine provides a modest reducing effect on body weight, BMI, and fat mass (2).

Exercise performance
The fat metabolism process is so important during periods of increased energy demand, like doing exercise. Taking an L-carnitine supplement is good for improving exercise performance. Increasing the use of fat through L-carnitine helps the body during rapid muscle movements. But the evidence for exercise endurance is mixed, and individual responses to the uptake of L-carnitine vary.

Brain function
L-carnitine in the brain plays a role in cognitive and memory functions. In recent years, the therapeutic potential of L-carnitine and its derivative acetyl-L-carnitine (ALCAR) has been studied for brain protection in disorders such as Alzheimer’s disease and hypoxia-ischemia. In a rat study, an effect on brain synaptic functions was examined, and results indicate that L-carnitine increases neurotransmission in the brain and consequently improves learning capacity in aging rats (3). Acetyl-L-carnitine is an acetyl derivative of L-carnitine, and it is used as a cure for many diseases, such as cognitive deficits in patients (4). However, further studies are needed to understand the potential of L-carnitine in the brain.

Antioxidant properties & Heart health
Because L-carnitine and its esters help reduce oxidative stress, they have been proposed as a treatment for many conditions, i.e. heart failure and angina. L-carnitine may improve certain heart conditions, such as angina or heart failure. Some reported heart function improved. Other conditions, such as fatigue or improving exercise performance, are also beneficial.

It’s important to note that while animal-based foods contain more L-Carnitine, individuals who follow a vegetarian or vegan diet can still obtain adequate amounts of this amino acid through a balanced diet that includes plant-based sources like tempeh and asparagus. Keep in mind that L-Carnitine requirements can usually be met through a well-rounded diet.

References
1) M. Pooyandjoo, M. Nouhi, S. Shab-Bidar, K. Djafarian, A. Olyaeemanesh.
The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials. Obesity Treatment/Etiology and Pathophysiology. Volume17, Issue10, October 2016, Pages 970-976.
2) Nasir Talenezhad a b, Mohammad Mohammadi a b, Nahid Ramezani-Jolfaie a b, Hassan Mozaffari-Khosravi b c, Amin Salehi-Abargouei a b. Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis. Clinical Nutrition ESPEN. Volume 37, June 2020, Pages 9-23.
3) Satoru Kobayashi, Machiko Iwamoto, Kazuo Kon, Hatsue Waki, Susumu Ando, Yasukazu Tanaka. Acetyl-l-carnitine improves aged brain function. Gerontology and Geriatrics Scien. Volume10, Issues1, July 2010, Pages S99-S106.
4) Hollister L, Gruber N. Drug treatment of Alzheimer’s disease. Effects on caregiver burden and patient quality of life. Drugs Aging 1996; 8: 47–55.