Your Expert Guide to Carnitine

in Sportsfuel Articles and Blog
Your Expert Guide to Carnitine
In the world of dietary supplements, nutrients can be a bit like fashion accessories. They bust out on the scene and set a big trend. Soon, everyone is using them. They're the big talk at the gym, and there are countless stories written about them in magazines and online. Then, another nutrient emerges, overtakes its popularity and that previous miracle solution for bodybuilders or athletes becomes forgotten.

That's the story of l-carnitine's  arrival to the dietary supplement scene in the 1980s. When it was first released in supplements as a fat burner, everyone wanted to get their hands on a bottle, but soon enough, stimulant fat burners emerged on the market and carnitine became less and less popular.

Now, with the benefit of 30 years of research verifying its benefits, l-carnitine is re-emerging as a popular supplement, not just for those who want to maximize fat burning, but also for enhancing performance and assisting with recovery.

Check out this expert guide to carnitine and learn how it works and can be use to enhance performance.

All About L-Carnitine

L-carnitine is often thought of as an amino acid, but despite how similar its name is to the essential amino acids, the nutrient is technically not one. Instead, l-carnitine can be thought of something like a cross between an amino acid and a B vitamin. In fact, when it was first discovered, l-carnitine was called vitamin BT because of how similar it is to the nutrients in the B vitamin complex.

Unlike essential nutrients, l-carnitine is produced by the human body, so it doesn't have to come from food alone; however, you can get doses of it in your diet. Red meats are the best sources of l-carnitine. Vegans can get small amounts from avocados and soybeans.

When l-carnitine is manufactured in the human body, the process takes place in the kidneys and the liver with the amino acids methionine and lysine serving as the raw materials. Most l-carnitine is stored in the muscle tissue, the brain and the heart.

What Forms of L-Carnitine Are There?

There are two main types of l-carnitine


The d-carnitine form of carnitine is not biologically active, so it cannot be used in dietary supplements to increase your supply of the nutrient.


L-Carnitine is the biologically active form of carnitine and can be found in dietary supplements in its raw, free form or in the following forms:

• L-carnitine tartrate. This form of l-carnitine is produced by combining carnitine with tartrate derived from tartaric acid. In clinical studies, L carnitine tartrate is shown to offer similar benefits to free l-carnitine.

• Propionyl-L-carnitine. This form of l-carnitine is produced by combining carnitine with an ester of propionic acid. Like L carnitine tartrate, propionyl-L-carnitine is shown to offer the same benefits as free l-carnitine when used as a supplement.

• Acetyl L-carnitine. This form of l-carnitine is produced by combining carnitine with an acetyl group. Studies show that this form of l-carnitine may have antioxidant benefits to fight oxidative damage due to free radicals, a property other forms of l-carnitine lack. At the same time, this form of l-carnitine offers the same benefits as the other versions of the active form of carnitine.

What Does L-Carnitine Do in the Body?

L-carnitine is a part of a number of processes in the body but its most important role is in the metabolism of fat. The nutrient acts like a vehicle, driving fats into cellular mitochondria.

Once l-carnitine drops off these long chains of fatty acids, the mitochondria break them down and use them to produce energy or ATP to power your body. Research shows that l-carnitine helps with fat metabolism in this way throughout the day, but that it is most active during periods of physical activity.

In addition to its important role in fat metabolism, l-carnitine assists with blood glucose control. The l-carnitine stored in the muscles makes the tissue more sensitive to insulin, resulting in lower blood glucose levels.

How Can L-Carnitine Help You Achieve Your Workout Goals?

Studies have revealed a number of ways that l-carnitine can potentially help anyone who works out regularly:

Fat Burning Support
Increasing your body's supply of l-carnitine with supplements can help shuttle more body fat to the cells to help you get shredded during workouts.

Fatigue Fighting
Studies have shown that increased levels of l-carnitine are associated with increased endurance. Taking a supplement could help you to hold off fatigue for longer, so that you can complete longer training sessions.

Support for Recovery
Research has revealed that l-carnitine enhances circulation to the muscles, delivering more nutrients, oxygen and hormones to the tissue. This can assist with the recovery process.

Effects on Body Chemicals & Complexes
L-carnitine seems to have a protective effect on nitric oxide, helping to prevent its breakdown due to oxidation. In addition, l-carnitine helps testosterone bind to muscle cells more readily. The nutrient also enhances the activity of a key growth factor in the muscle cells. When you combine all three of these benefits together, l-carnitine can support muscle development indirectly by helping to promote conditions where new cells can be produced more speedily and efficiently.

While it doesn't have anything to do with athletic performance, l-carnitine is also believed to enhance male performance in the bedroom by enhancing blood flow to the genitals.

Does L-Carnitine Cause Side Effects?

When taken in low doses, l-carnitine has not been shown to cause major side effects. At high doses it does have the potential to cause gastrointestinal side effects like nausea, vomiting and diarrhea. Due to the risk of health complications, it's not advisable for people with kidney disease, kidney injuries or seizure disorders to take l-carnitine.

There was a single study that suggested that l-carnitine could raise the risk of hardening of the arteries; however, there have been studies that also indicate that l-carnitine is beneficial for the heart and capable of lowering cardiovascular disease risk.

When and How to Take L-Carnitine

In order for most forms of l-carnitine to provide maximum benefits, they need to be taken alongside carbs. This is because insulin levels need to be at high levels in order for enough l-carnitine to enter the muscle tissue to produce noticeable results.

If you're planning to take an l-carnitine, L carnitine tartrate or propionyl-L-carnitine supplement, it's best to take roughly 2 to 3 grams per dose and to use it with 30 to 40 grams of carbs and 20 to 40 grams of protein. To get the right dose of nutrients, it's therefore best to take it with a meal. Most experts recommend that it be the next meal after your workout. If it's not convenient for you to wait until after your workout or you don't work out near any meal time, you can take the supplement with any meal that has the optimal amount of carbohydrates and protein.

If you're hoping to reap the potential extra health benefits of acetyl-L-carnitine, it's best to take the supplement without food at some other time of the day. Studies show that this form of l-carnitine is better absorbed by the muscle and brain when it's consumed alone. As a result, people who want to stack l-carnitine along with other fat burning supplements are typically well served to select an acetyl-L-carnitine supplement over an l-carnitine, L carnitine tartrate or propionyl-L-carnitine supplement.

You don't have to choose to take only an l-carnitine, L carnitine tartrate or propionyl-L-carnitine supplement or an acetyl-L-carnitine. Some experts propose taking 2 to 3 doses of acetyl-L-carnitine on its own or with other fat burners in between meals and then taking a single dose of l-carnitine, L carnitine tartrate or propionyl-L-carnitine with a meal after a workout.

No matter which form of l-carnitine you use, you don't have to cycle it in order to continue seeing results. There is no evidence that taking a break from the supplement and then restarting enhances or alters the performance of supplements.

The Takeaway

When you use l-carnitine correctly, its benefits can help you get more out of your workouts and help you to achieve your fitness goals more efficiently and quickly. The key is to find the right supplement for your needs and to use it as described above and recommended by the manufacturer.

Our team at Sportsfuel can help you pick out the perfect carnitine supplement to add to your diet, so that you can get the fat-burning, energy-supporting benefits of this nutrient. Contact us for assistance with your shopping or start browsing our selection of carnitine supplements now.

Leave a comment

Please note, comments must be approved before they are published