There are currently no items in your basket.


The Best Supplement for Rapid Fat Loss – L Carnitine

Reading Time: 6 minutes

By Myprotein Writer Joe Neill 
Personal Trainer
No Limits Strength and Conditioning Centre Liverpool


What is L Carnitine?

L Carnitine is most commonly known to help the body produce energy by freeing up fatty acids, which has been said to aid fat loss.

It is often mistaken for an amino acid but is actually synthesised in the body from amino acids, lysine and methionine.

L Carnitine is produced in the liver and kidneys in addition to being available through animal sources – predominantly red meat and dairy – and conveniently enough, supplement form.

A study in The Journal of Physiology provides evidence that L-Carnitine supplements enhance athletic/physical performance, which additionally contributes to creating leaner muscle mass!

The average human body contains around 20g of stored L Carnitine, the majority found within the skeletal muscle.

However, this is not an effective amount for individuals to benefit from L Carnitine’s great health benefits, in which additional  doses are often consumed by individuals for maximum results.

morning person

How does it work?


L Carnitine is primarily concentrated in tissues which predominantly use fat for energy, such as skeletal and cardiac muscle (e.g. biceps and heart).

It acts as a bridge for long chain fatty-acids from food (including the nasty stuff) to be carried into small, sweat-collecting cells inside larger cells, namely known as mitochondria.

The process then consists of the fatty acids being metabolised (broken down) to use as energy, or as most sports-people would see it – fuel for efficient exercise.

It is somewhat different to medium/short chain fatty acids which can freely pass into a cell. (1)

As you can imagine, having a sufficient amount of L Carnitine in your body could immediately prevent frustrating muscle fatigue and have a positive effect on poor motivational levels, induced by a lack of energy – whether you’re a bodybuilder, athlete or gym goer!

A stored reserve of the non-essential amino acid can aid the conversion of fat to fuel:


More L Carnitine = More training fuel = Better results!

Although no studies have proved definite results for fat loss, L Carnitine has been found to favour aerobic exercise, resulting in improved endurance performance! (2)


The benefits of L Carnitine

L Carnitine is linked with benefits in a number of capacities, including:


– Fat loss

– Increased athletic performance

– Better health and well being

– Increased concentration levels.

leucine for weight loss

The arguments for improvements in performance are down to L Carnitine’s ability to increase the metabolism of fat cells, which creates more energy allowing you to perform exercise at higher intensities for longer periods of time, whilst producing less lactic acid. (3)

Due to L Carnitine’s role in transporting fatty acids into cells to be oxidised, (burned for energy) it has been examined in a number of studies to witness the effect it has on body composition – this is due to the possibility that it can aid higher intensity exercises for longer periods and play a part in the increase of at burning.


L Carnitine plays a role in the prevention/treatment of certain health issues such as heart failure, angina, kidney disease, dementia and obesity (yes obesity is a health issue!)


L Carnitine supplements

As mentioned, L Carnitine has numerous benefits which can be gained from ensuring you are getting enough of this non-essential amino acid.

A high percentage of the L Carnitine your body requires is going to be taken in through animal food sources – this could be problematic for those with hectic/busy lifestyles.

Some individuals may also be naturally deficient in L Carnitine, this means they may need to increase L Carnitine levels through supplementation.

L Carnitine is available in a variety of forms such as capsules and powders.

If needed for health reasons a medical professional will most likely prescribe it in the form of capsules.

With L Carnitine’s role in fatty acid metabolism it is often found in many over the counter ‘fat burner’ supplements, on the premise that the more fat made available for use as energy, the quicker you will reduce weight and excess body fat.


L Carnitine for performance


However, as mentioned above there is a lack of evidence suggesting its effectiveness when it comes to fat loss.

If you are interested in using L Carnitine purely for performance reasons, then using the supplement in single form is the best option.

With the potential benefits on performance this is a useful supplement for any athlete to use in their training or during competition.

Research has shown that athletes who perform regular endurance activities (e.g. long distance runners) have deficiencies in the amount of stored L Carnitine in their muscles, which suggests that this supplement may be vital to the endurance athlete population in order to maintain fitness and aid faster recovery!

If this is the case for you, L Carnitine, compact and convenient shots with added Beta Alanine may be the right supplement for you to throw in your training bag.

Simply drink your 60ml shot 45-60 minutes pre-workout for an energy boost to improve physical performance, of which may consist of explosive movements.

training water weight

Dosage and when to take



The recommended dose is 2-3g per day – this can be taken at different times of the day depending on the reason for using the supplement – however, it is usually recommended to consume between meals.

For those using it for performance reasons, it is best to take around 30-60 minutes pre-workout.

For fat loss benefits, some suggest consuming L Carnitine post-workout, however, it can be taken throughout the day, in between meals as mentioned – even in split servings (e.g. 1g per 2 capsules/ 1g powder scoop, morning, and afternoon/morning and night/afternoon and night).

It’s not a supplement that will have the effect of caffeine, keeping you awake if you do happen to take it at night!


Take home message


Cited with benefits in health, fat loss and performance, L carnitine could be an extremely useful supplement to a number of people with different training strategies and goals.

For your professional athlete I think it would be foolish not to consider using the supplement regardless of conflicting evidence, as it is cheap, easy and safe to use and could give you a boost in performance, even if only slight – small percentages can be the difference between success and failure.

For those wanting a lean look (abs anyone?)  you may want to put a bit more thought into purchasing this or any ‘fat burning’ supplements with L carnitine as a main ingredient, simply because of the lack of evidence suggesting positive effects on fat loss.






Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you’re concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.



Writer and expert

30% off Best Sellers - Use code BEST Be quick, shop now!