L- what?? The powerhouse supplement for your heart that you probably haven’t heard of

So this post is second in my series on all things energy. My last post was all about the battery-recharging nutrient Co-enzyme Q 10 (CoQ10) which helps to improve the cell’s uptake of energy in the mitochondria (the energy production centre of the cell). So you’ve now learnt all about CoQ10 and the importance of it for heart health, in particular if you’re on a statin, what else can help to improve heart health? Should you just take CoQ10 and leave it at that? Well, would you drink a green juice in the morning but then eat a burger for lunch if you were on a mission to improve your health? Probably not. So why take only one supplement? Enter L-Carnitine, an amino acid that is not only as important for energy production as CoQ10, it could be MORE important! Think of it as the broccoli of the amino acid world – a powerhouse of hardworking ‘truck drivers’ – delivery drivers of the oxygen and energy production world. So why haven’t we heard of it more often? It’s actually used frequently in the fitness world, where athletes, bodybuilders and long distance runners/cyclists use it to improve their oxygen uptake into the cells, as well as a helping hand in converting fat into energy aka for fat loss.

abstract blackboard bulb chalk
Could you do with more energy? L Carnitine may help. Photo by Pixabay on Pexels.com

So what is L-carnitine?

It’s a water soluble nutrient made up of two amino acids, lysine and methionine. It helps to transport oxygen and fatty acids to the cells across the mitochondrial membranes where it’s friend CoQ10 helps to convert them into energy. L-carnitine also assists in recycling CoQ10 so your cells stay fuelled for energy.

L-carnitine’s function as a ‘transporter’ is improved if your mitochondria are better able to process fatty acids and move them through the energy production cycle. And who helps to do this? CoQ10 – which helps to “clear the deck” by increasing ATP (the energy ‘currency’) production at the end of this process.

Another benefit of L-carnitine is that after energy is generated in your cells, it picks up the toxic fatty acid waste products of the energy production process and transport these out of your cells. If L-carnitine didn’t clear out these by-products, they can build up in the cells, placing severe stress on your heart. This can lead to damage to your cell membranes and over time you can end up with atherosclerosis of the heart.

Another problem is that if these waste products are not cleared out, they can cause vasoconstriction, meaning narrowing of the arteries. Therefore L-carnitine is also helpful for people with claudication of the extremities – pain or cramping in the legs with activity, including walking because L-carnitine helps to deliver oxygen to blocked arteries, prevents vasoconstriction (through removal of waste products) and can even help to treat congestive heart failure.

Can L-Carnitine really help heart failure?

In those with congestive heart failure (CHF), levels of L-Carnitine in muscle fibres are lower, whilst levels in the blood plasma are higher. This may indicate that muscle breakdown is higher amongst those with CHF compared with those without. A study found that l-carnitine helped to reduce the muscles wastage (myopathy) associated with heart failure (Vescovo, 2002). Vescovo’s et als study found that whilst L-Carnitine supplementation did not prevent heart failure from developing, it significantly helped to reduce muscle atrophy (wastage), which could help to preserve exercise capacity. It makes sense too that if L-Carnitine can reduce muscle breakdown in the skeletal muscle, it could also prevent breakdown of muscle in the cardiac muscle.

Double-blind clinical trials have also shown that L-carnitine supplements improve exercise capacity in people with heart disease-related chest pain (angina). The patients taking the supplement (2g/day) also showed a significant reduction in the number of premature ventricular contractions (PVC) at rest (Cacciatore et al, 1991). What’s not to like?

red love heart christmas
Can your heart be helped by giving it more energy for it’s cells? Photo by Pixabay on Pexels.com

Sounds great – why aren’t we all taking it?

There was a bit of a scare a little while ago about L-Carnitine when a study was published that suggested that orally dosed L-carnitine is metabolized by intestinal bacteria to produce a substance called trimethylamine (TMA). TMA is possibly further metabolized into trimethylamine-N-oxide (TMAO). There is a theory that TMAO prevents excess cholesterol from being excreted, thus allowing it to infiltrate artery walls, which is being studied as a possible culprit for increased risk of cardiovascular disease. Sounds a bit scary, doesn’t it? So does that mean that you should avoid L-carnitine?

So what does this particular study mean for me?

It’s important to keep in mind that the study subjects (both humans and mice) were given “large” amounts of l-carnitine. While we do not know how much was given to these test subjects, previous research done on humans suggests that a very large amount of l-carnitine (6 grams total/day) is required for significant increases of plasma TMAO. Other dosages administered three times daily (a total of 1.5g, and 3g total per day) showed no change in plasma increases of TMAO (Bain et al, 2006). L-carnitine therefore appears to be safe up to 3g per day.

Does the body make L-Carnitine? Can I eat it?

Your body produces L-carnitine with the help of two amino acids – lysine and methionine – as well as Vitamins C and B6, iron, and niacin. L-carnitine is found in foods such as lamb, beef and pork. Vegetarians can supplement and/or combine such foods as beans and rice, which contain lysine and methionine.

steak meat raw herbs
L-Carnitine is found in meat. Photo by mali maeder on Pexels.com

How Much L-Carnitine Should You Take?

L-carnitine is not very bioavailable. As there are various forms of L-carnitine, supplementation with a broad-spectrum product that contains L-carnitine fumarate, acetyl-L-carnitine, and propionyl-L-carnitine is the optimal choice. Because L-carnitine doesn’t get fully absorbed when taken orally, ingesting it in smaller doses 3 times per day on an empty stomach is the preferred method. It is always best to start with a low dose, gradually increasing it until a desired effect is achieved.

  • 400 – 800 mg daily (especially for vegetarians) to prevent deficiency
  • 500 -1,000 mg two-to-three times daily if you have coronary artery disease or angina
  • 1 – 2 grams (sometimes up to 3 grams) daily for arrhythmia
  • 2 – 3 grams daily for congestive heart failure or following a heart attack.

You can also get some L-carnitine in your diet, especially in lamb, pork, beef, and chicken.


L-carnitine and CoQ10 are essential team-mates in cellular energy production (see above) so you will need to supplement with CoQ10 too for the best benefit.  As everyone has a different health history and need, make sure to ask your doctor and pharmacist if L-carnitine and CoQ10 could benefit you.

Where can I buy it?

Dynamic Health – 1000mg L-Carnitine with 25mg CoQ10. Comes with a small dose of CoQ10 but is a well known, quality brand.

Supplemented Acetyl-L-Carnitine 500mg 180 Tablets – A good dosage at a lower price however the tablets are quite large so you may struggle to swallow if you have difficulty with larger tablets.

Cytoplan Cyto-Renew contains 200mg Acetyl-L-Carnitine along with Alpha Lipoic Acid, Ginkgo Biloba, 25mg CoQ10, N-Acetyl-L-Cysteine and Rosemary extract 5:1. A good brand but works out more expensive as you will have to take more tablets to hit the dosage needed. 10% off with the code HA10.

Please note that the information provided is a guide only and does not take into account your individual circumstances. Please seek advice from a medical professional before commencing any exercise programme or new diet. Please seek advice from your doctor AND your pharmacist before starting any supplements.


Bain et al (2006).  Disposition and metabolite kinetics of oral L-carnitine in humans. Journal of Clinical Pharmacology. 46(10):1163-70.

Cacciatore et al (1991). The therapeutic effect of L-carnitine in patients with exercise-induced stable angina: a controlled study. Drugs Under Experimental and Clinical Research. 17(4) 225-35.

Vescovo et al. (2002). L-Carnitine: a potential treatment for blocking apoptosis and preventing skeletal muscle myopathy in heart failure. American Journal of Cell Physiology. 283: 802-810.

2 Comments Add yours

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.