Carnitine or L-Carnitine
Types, Sources, Benefits, Side Effects, Supplements & Dosage

What is L-carnitine?

L-carnitine is known as an amino acid, which is a building block of protein in nature. It is derived from two essential amino acids, methionine and lysine. L-carnitine is produced in our body naturally but can be taken from outside food sources such as meat products or fish in your diet, which makes it a conditionally essential amino acid. It is also present in supplement form. Vegan people or people with certain hereditary issues can take carnitine supplements to acquire enough carnitine in their bodies.

L-carnitine has a vital role in the improvement of one’s heart health. It improves the functioning of the brain and assists the body in muscle movements. Intake of l-carnitine may improve the metabolic parameters of our body, which further reduces the risk of cardiovascular complications.

It helps in the gain of strength and lean muscle mass as it reduces fatigue. Using carnitine has been shown to increase muscle function in adults. Another role of carnitine is that it suppresses appetite, so a person will stop time-wasting munching and will maintain his goals. 

Types of L-carnitine

Carnitine has many types, which are discussed as follows:

Acetyl L-Carnitine

This type of carnitine is used to help the nervous system because it has neuroprotective effects. It is used for Alzheimer's disease, improving thinking skills, and improving memory. It helps with the tingling feeling, lowers pain in the nerves, and reduces cholesterol levels in diabetic patients. Some studies show that it improves the metabolic rate as well.

Propionyl-L-carnitine

This type helps in the maintenance of cardiac health. Because it has the properties of relieving pain and having antirheumatic effects. It helps in bettering the circulation in the body because it causes a boost in nitric acid production, which promotes blood flow, and it aids the body in producing energy and stimulating ischemic muscles.

D-carnitine

It is a toxic compound for the body as it inhibits the absorption of other chemicals. It is known as an isomer of l-carnitine, and it is an inactive form.

L carnitine L Tartrate

This type has a good and rapid rate of absorption, and it is mostly added to sports supplements because of its beneficial properties, which help in reducing muscle soreness and aids in fastening the recovery in workouts. It stimulates the oxidation of fatty acids and lowers the formation of free radicals in the body.

Sources of L-carnitine

Food Sources To Obtain Carnitine

A small amount of carnitine can be obtained from various food sources. Following is the list:

• Beef is a good source of carnitine, naturally. It can provide 81 mg of carnitine per 3 ounces.
• Fish is a beneficial source of carnitine. It can contribute up to 5 mg of carnitine per 3 ounces.
• Chicken also provides carnitine for our bodies. It has 3 mg of carnitine per 3 ounces, or 85 grams of chicken.
• Milk: It provides 8 mg of carnitine per 8 ounces or 227 ml.

L-carnitine supplements

L-carnitine, propionyl-L-carnitine, and acetyl-L-carnitine dietary supplements are available worldwide in the form of pills, capsules and powder.

There is a widespread interest in l-carnitine supplements among athletes for the improvement of their athletic performances and energy levels. L-carnitine supplementation expands the muscle content and optimizes the oxidation of fat. Also, it lowers fat storage availability in the body.

How Carnitine Helps in Weight Loss

The simple mechanism of L-carnitine is that it carries long chains of fatty acids inside the mitochondria of the cell, so these chains can be oxidized there and further converted into energy. 

Benefits of L-Carnitine:

Intake of carnitine can provide various benefits to the body.  Let's take a look at some of the benefits that l-carnitine can have on your goals and your health.

It Improves Brain Health

It has been shown that the intake of carnitine supplementation may prevent mental decline and stress-related damage by increasing the levels of a neurotransmitter, acetylcholine. In addition, it helps with brain diseases, specifically Alzheimer’s disease, as it improves memory and slows the rate of disease.

It Betters our Cardiac Health

Carnitine has the potential to lower cardiovascular disorders as its intake can improve blood pressure, reduce inflammation and oxidative stress, and decrease heart muscle damage. Furthermore, it triggers cardio-protective effects, which will reduce the risk of ischemia and prevent complications following a cardiac arrest. In addition, the intake of carnitine can also diminish angina symptoms. Angina is a type of chest pain that is caused by the reduced flow of blood to the heart.

Exercise Performance

An improvement in exercise performance is seen by the intake of carnitine. It aids in tissue recovery, supplies oxygen in muscles and tissues, reduces muscle soreness, increases stamina because of vasodilation of nerves, and improves muscle physiology. 

Consumption of l-carnitine increases athletic performance during workouts.

Helps With Diabetes Symptoms

The use of carnitine and acetylcarnitine can be beneficial for diabetes types 1 and 2. It lowers the symptoms of diabetic neuropathy in type 1 and reduces the levels of cholesterol, glucose, and triglycerides that aid in diabetes type 2. 

In insulin-resistant patients, l-carnitine enhances the sensitivity of insulin.

Aids With Asthma

In some studies, using l-carnitine supplements has shown control in asthma and improved the function of the lungs. As it reduces the inflammation in the lungs and improves the saturation of oxygen.

Good For Liver Health

As we know, l-carnitine transfers fatty acids in mitochondria for their oxidation; it will also take excess acetyl CoA away from the mitochondria, which will maintain the circulation and functions of the liver. Also, it helps in the metabolism of lipids, which will maintain the health of the liver.

Prevention Of Renal Failure

Kidneys in our body produce carnitine. If there is a kidney disease, then carnitine levels will be low in our body. Taking a good and proper supplementation of carnitine will make up for the deficiency of carnitine. Taking the supplements by consulting your doctor will prevent renal disorders or their failure.

More Energy Levels

Including carnitine in your diet will increase your energy levels. A person can do much better in his or her workout due to higher levels of energy. Usually, l-carnitine is a pre-workout supplement because it is taken before a workout.

Act as a test booster

Consumption of carnitine can improve testosterone production in men. It will help in energy generation, improve the flow of blood, and improve sperm motility in males.

Side Effects of L-Carnitine

Generally, intake of l-carnitine is safe and does not contain any side effects when taken as a dietary supplement. It provides some favorable benefits but along with these advantages, consumption of l-carnitine may cause a few side effects in some individuals. Side effects may vary from person to person.

L-carnitine Carnitine effects that are common

• Diarrhea.
• Cramps in the stomach.
• Vomiting or feeling of nausea.
• Headache.
• High blood pressure.

L-carnitine Carnitine effects that are less common

• Impairment in vision.
• Body odor.
• Depression.
• Sensation of tingling.
• Dizziness.
• Weakness.
• Rapid heartbeat.
• Fever.

L-carnitine dosage

Many people endure L-carnitine well. The suggested measurements are about 1-3 grams per day for 12 months. However, individuals with genetic conditions and irregularities causing an absence of L-carnitine should consult their doctors for a more precise dosage.

Acetyl-L-Carnitine Dosage

The recommended measurement for acetyl l-carnitine is 1.5–3 grams per day for 33 months. however, ask your health consultant to tell you about measurements according to your condition.

Propionyl-L-Carnitine Dosage

The suggested measurements for the intake of propionyl l-carnitine are recommended as 1.5–2 grams each day for up to 6 months.

L-carnitine L-Tartrate Dosage

Doses of l-carnitine l-tartrate may vary from 1000 mg to 4000 mg each day. But the best use will be prescribed by your physician.

Conclusion

L-carnitine is one of the most well-researched and beneficial supplements for improving energy metabolism, enhancing exercise performance, and supporting heart health. It helps the body use fat as fuel, boosts stamina, and assists in faster recovery after workouts. Beyond its athletic benefits, it also plays an important role in brain function, diabetes management, and liver protection. The body can naturally produce carnitine, but dietary intake from meat or supplements ensures optimal levels, especially for vegetarians and people with low muscle carnitine stores.

When taken under proper guidance and within recommended dosages, L-carnitine is safe and highly effective. However, it is not a quick-fix solution for fat loss or energy; it works best when combined with a balanced diet, regular exercise, and a healthy lifestyle. Consulting your healthcare provider before starting supplementation ensures that it suits your specific health condition. With consistent use and professional supervision, L-carnitine can significantly improve your overall health, performance, and vitality.

FAQs:

Is L-carnitine better than carnitine?

Yes, L-carnitine is the active and most beneficial form of carnitine that the body can effectively absorb and utilize. It plays a key role in transporting fatty acids into cells where they are converted into energy. Other forms like D-carnitine are inactive and may even block the natural activity of L-carnitine, which makes them less desirable. L-carnitine is the preferred form for athletes, fitness enthusiasts, and people aiming to enhance energy metabolism or support heart and brain health. Always ensure the supplement label specifies “L-carnitine” for maximum effectiveness.

Does L-carnitine reduce belly fat?

L-carnitine may help reduce belly fat when combined with exercise and a calorie-controlled diet. It enhances fat oxidation by transporting fatty acids into the mitochondria, where they are burned for energy. This process helps decrease fat storage, especially when your body is in a calorie deficit. However, it is not a magic fat burner on its own. Consistent use, proper diet, and regular physical activity amplify its results over time. Many people notice a gradual reduction in stubborn fat areas along with improved endurance and muscle definition.

What foods are high in carnitine?

Foods rich in carnitine mainly come from animal sources since it is naturally found in muscle tissue. Beef provides the highest amount, followed by lamb, pork, chicken, and fish. Dairy products like milk and cheese also contain moderate levels of carnitine. Plant-based foods, on the other hand, have very little carnitine, which is why vegetarians and vegans are more likely to benefit from supplementation. Including these protein-rich foods in your meals supports healthy energy production and muscle function naturally.

Who cannot take carnitine?

People with certain medical conditions should avoid taking carnitine without consulting their doctor. Individuals with hypothyroidism, seizure disorders, or chronic liver disease should be cautious, as L-carnitine may interfere with medication or worsen symptoms in rare cases. Pregnant or breastfeeding women should also seek medical advice before use. Additionally, those who are sensitive to supplements or have high blood pressure should start with a lower dose to monitor their body’s response. Always discuss with a healthcare provider before starting supplementation to ensure safety and suitability.

Is L-carnitine safe for kidneys?

L-carnitine is generally safe for the kidneys when taken in the right dosage and under medical supervision. In fact, it may be beneficial for people with mild kidney issues, as it helps maintain energy metabolism and supports muscle function. However, patients with advanced kidney disease or those undergoing dialysis should only use it if prescribed by a doctor. Overuse or self-medication can lead to an imbalance of metabolites in the blood. Proper medical guidance ensures that supplementation remains safe and effective without putting stress on the kidneys.