Everything You Need to Know About L-Carnitine

Everything You Need to Know About L-Carnitine

L-Carnitine has been one of the most popular and most talked about supplements here in 2019. When taken properly, L-Carnitine can greatly benefit both your training and your physique. L-Carnitine can be both a performance booster leading to more endurance and greater pumps, and for your physique and body type it can mean more muscle, less fat, and more confidence when looking in the mirror.

So What Is L-Carnitine?

Many people mistakenly believe L-Carnitine is an amino acid. L-Carnitine actually is not an amino, it's a compound which is related to the B Vitamin family. L-Carnitine was first studied back in the 1950's, and was initially referred to as Vitamin BT.

L-Carnitine is formed from the amino acids lysine and methionine, and is formed in the kidneys. It's also however stored in other areas of the body, such as muscles, including the heart and brain. You can also get L-Carnitine from your diet, mainly from eating meat and animal products. For those of you who are vegans or vegetarians, you can also get L-Carnitine from soybeans, and even avocados. Red meat however is typically the best source for L-Carnitine.

There are actually two different forms of carnitine. There's D-Carnitine and L-Carnitine. While actually very similar, D-Carnitine is biologically inactive and therefore is not used for supplementation. Acetyl L-Carnitine is also known as ALCAR and is another popular form of carnitine. ALCAR is found in the central nervous system and it plays an important role in energy and produces the neurotransmitter acetylcholine.

The acetyl group attached to the carnitine molecule helps it pass through the blood brain barrier and enter the brain where it also acts as an antioxidant. In addition to the benefits already mentioned above, there's many who believe L-Carnitine may provide protection against the aging process and neurodegeneration.


L-Carnitine transports long chain fatty acids into the mitochondria of cells. Once there, the fatty acids can be oxidized and then used as fuel. This is done to generate adenosine triphosphate, or ATP. L-Carnitine does this cellular work both when at rest, as well as when you're working out. It's believed however that L-Carnitine is most effective when used during intense exercise.

Without an appropriate amount of carnitine, most dietary fats will not get into the mitochondria and be burned for fuel. Being deficient in carnitine is a serious medical condition and can lead to muscle weakness, and other problems. This is why L-Carnitine is considered to be a "conditionally essential" nutrient. This means your body produces it, but if your body doesn't produce appropriate amounts your health can be negatively affected.

Recent studies have shown that besides just transporting fat, it can also enhance insulin's action on muscle cells. If this is true it means that L-Carnitine can potentially help keep blood glucose at healthy low level, even after consuming carbs. This is why many recommend taking L-Carnitine after your most carb heavy meal of the day.


L-Carnitine is widely known to be an effective fat burning supplement. Because of this it's also often used during bulking season to help people limit fat gains and acquire an overall much cleaner bulk. For those who are cutting, L-Carnitine can help transport fat into your cells to be burned off as energy.

Burning Fat: Research on L-Carnitine focuses on fat burning and athletic performance. One particular study had two separate groups of athletes take 2 grams of L-Carnitine with 80 grams of carbs in the morning and afternoon. The control group took only carbs. Researchers discovered that during even low intensity cycling, the subjects which took carnitine burned 55% glycogen and also increased their ability to burn fat by 55%. During high intensity cycling, the group taking L-Carnitine had lower levels of lactic acid along with higher levels of creatine phosphate which is a primary building block of ATP.

Endurance: In another study researchers measured the subject's ability to resist fatigue during a cycling workout. They found when taking L-Carnitine, subjects were able to cycle 25% longer than those not supplementing with L-Carnitine. Researchers believed this was because they burned more fat while preserving more glycogen, along with having lower levels of lactic acid and higher levels of creatine.

Recovery: Several studies on human subjects found that L-Carnitine doses of just 1-2 grams per day are shown to reduce muscle damage, and improve recovery. L-Carnitine has also been shown to reduce muscle soreness post workout.

Improved Pumps: L-Carnitine will pump you up. L-Carnitine's benefits go beyond just helping to burn fat and decrease glycogen use. L-Carnitine has also been shown to help to increase blood flow to muscles. Increasing blood flow means more nutrients go to where they're needed during workouts.


L-Carnitine has few if any side effects from supplementing with it, especially in lower doses. L-Carnitine can however cause abdominal cramps, vomiting, and diarrhea when taken in high doses.


Unlike fat burners, prohormones, and pre-workouts, there doesn't seem to be any need to cycle L-Carnitine. Even taken regularly, L-Carnitine should be effective even when taken long term.


One of the best times to take your L-Carnitine is after a workout, however L-Carnitine is also great to take with any high carb or high protein meal throughout the day. Ideally you'll want to take L-Carnitine after your most carb heavy meal of the day.

Should you choose to stack L-Carnitine with fat burners between meals, L-Carnitine is the deal type of carnitine to take.


So you've decided you want to start supplementing with L-Carnitine, and you're looking to choose a product, but you're wondering whether to buy a liquid L-Carnitine product, or a capsule L-Carnitine product.

A lot of this comes down to personal preference. Some people have a hard time swallowing pills, and with Carnitine products the dosage tends to be a lot of pills. You really can't go wrong either way, but there are some additional benefits to taking liquid L-Carnitine.

Liquid L-Carnitine tends to be a bit cheaper than capsules or pills. Liquid L-Carnitine products tend to be dosed more heavily as well. 5% Nutrition's Liquid L-Carnitine 3150 for example contains 3150mg of Carnitine. Many of the popular capsule L-Carnitine products however only contain about 500mg of carnitine. This means you'd have to take about 6 pills to get an effective dose.

Both liquid and capsule forms of L-Carnitine are good, it really comes down to personal preference.

Jun 22nd 2023 Madison Tong
Madison Tong
Madison has been in the fitness and supplement industry now for almost five years. She prides herself with helping speak about the newest supplements and fitness trends to hit the industry. She loves the outdoors, endurance training and helping other meet their fitness goals.
Madison Tong

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