Carnitine helps burn fat for energy, improves blood glucose levels, and increases total energy expenditure.
Carnitine is found mainly in red meat. Plant-based foods contain negligible amounts. However, healthy people who want to lose weight don’t need to take carnitine supplements even if they follow a vegan or plant-based diet like the Mediterranean. The body synthesizes high amounts.
Table of Contents
- Does Carnitine help you Burn more Fat?
- Carnitine helps preserve Lean Body Mass while dieting
- How much Carnitine can the human body Synthesize a day?
- Foods rich in Carnitine
- Do people who follow the Mediterranean Diet get enough?
- How much Carnitine from Supplements for Weight Loss?
- Who should benefit from Carnitine Supplementation?
- Dangers & Long-Term Side Effects of Carnitine Supplementation
Does Carnitine help you Burn more Fat?
Carnitine is a compound found in nearly all cells of the body. The human body can synthesize adequate amounts of carnitine. Moreover, we can get it from animal-derived foods and dietary supplements.
Carnitine plays a key role in fat metabolism and energy production. It transports long-chain fatty acids into the mitochondria to be burned for energy. Hence, carnitine helps burn belly fat for energy.[1]
According to a 2020 study, carnitine supplementation can help overweight people lose weight, and decrease Body Mass Index and fat mass.[2]
Another recent study showed that L-carnitine supplementation can significantly decrease body weight and fat mass. However, only obese and overweight people could benefit from carnitine’s anti-obesity effects! Especially, when combined with moderate exercise and a hypocaloric diet.[3]
Moreover, L-carnitine supplementation may help obese people lose weight because it plays a key role in fat and carbohydrate metabolism, lowers blood glucose levels, improves glucose intolerance in conditions like obesity, decreases insulin resistance, and improves total energy expenditure![4]
But, if you want to lose weight, consuming fewer calories is far more important than getting high amounts of carnitine, either from food, or supplements.[5,6]
Carnitine supplements may offer benefits for specific groups, including those aiming to enhance athletic performance or improve fat metabolism.
Carnitine helps preserve Lean Body Mass while dieting
When we follow a diet low in calories for weight loss, we lose both muscle and fat mass. However, high carnitine intakes from supplements when dieting may prevent muscle mass loss.[7]
Additionally, carnitine is necessary for the synthesis of testosterone! High testosterone levels have been linked to decreased percentage of body fat. Moreover, testosterone is necessary for muscle growth and limiting muscle loss when being in a caloric deficit.
Actually, as carnitine is found mainly in the muscle tissue, it’s beneficial for muscle growth. Carnitine is a popular supplement among athletes and fitness enthusiasts. It acts as a fat burner. In fact, carnitine burns body fat for energy.
Athletes take carnitine to build muscle mass, improve performance, increase energy levels, and even decrease fat percentage. But, there isn’t consistent evidence that carnitine supplements can improve sports performance or body composition in healthy athletes.[8]
First, carnitine supplements may help athletes spare their glycogen storage. Especially, during low-intensity exercise (50% VO2max). It seems that carnitine burns body fat for energy, instead of muscle glycogen. Furthermore, carnitine can reduce muscle lactate accumulation at high-intensity exercise.[9]
So, carnitine is beneficial for endurance athletes and athletes who do resistance training for muscle growth and strength. According to a small study, carnitine supplementation increased work output of exercise by 11%.
Moreover, increased carnitine intake can reduce metabolic stress, and physical fatigue and promote recovery after exercise. So, it may enhance athletic performance.[10]
Furthermore, L-carnitine supplementation could limit the imbalance between protein synthesis and protein breakdown, supporting muscle growth.[11]
Carnitine may enhance endurance by increasing fat utilization for energy, sparing muscle glycogen, and reducing muscle soreness by minimizing oxidative damage after intense workouts. While these effects are more pronounced in individuals with low carnitine levels, healthy athletes may experience modest improvements when supplementing.
How much Carnitine can the human body Synthesize a day?
The total carnitine content of the body is about 20 grams for a person weighing 155 pounds (70 kg). Almost all of it is in the muscle tissue.
The human body synthesizes about 0.16 to 0.48 mg/kg of L-carnitine a day. So, a 155-pound person synthesizes between 11 and 34 mg of carnitine a day. Furthermore, kidneys reabsorbs about 95% of carnitine. Therefore, healthy people don’t need to eat foods with carnitine or take carnitine supplements. Even people who follow a plant-based diet and vegans can produce more than enough carnitine.[1,7]
Furthermore, the kidneys efficiently retain carnitine. Thus, even a diet low in carnitine has little impact on the total carnitine content of the body. People may need extra carnitine doses from supplements only under certain conditions.
Foods to boost Carnitine Synthesis
The human body needs certain compounds for the synthesis of carnitine. We should consume foods with methionine, lysine, vitamin C, and vitamin B6 to help the body produce enough carnitine for increased energy levels and weight loss.[8]
Foods with Methionine
Methionine is an essential amino acid for humans. The human body can’t synthesize methionine. We have to get it from the diet.
The richest foods in methionine from animal sources are eggs (3.1g per 100g), cod (3g), chicken (2.8g), beef (2.6g), pork (2.6g), and milk (2.5g).[9,10]
But, there are many plant-based foods with high amounts of methionine as well. The richest vegan foods in methionine are rice (2.4g per 100g), corn (2.1g), wheat and oats (1.8g), sesame seeds (1.6g), rye and beans (1.5g), cauliflower (1.4g), Brazil nuts (1.1g). hemp seeds (0.9g), soy protein (0.8g), chia seeds (0.6g), peanuts (0.3g), chickpeas (0.25g), and almonds (0.15g).
Foods with Lysine
Lysine is also necessary for the synthesis of carnitine. We must get it from food as well.
Good animal sources of lysine are high-protein foods, such as eggs, meat, and fish. On the other hand, beans and legumes are great plant-based sources of lysine. In fact, beans are among the best foods for weight loss.
Foods with Vitamins B6 & C
Foods rich in vitamin B6 include poultry like chicken and turkey, fish such as salmon and tuna, fortified cereals, potatoes, bananas, and spinach.
For vitamin C, the top sources are citrus fruits like oranges, lemons, and grapefruits, as well as strawberries, kiwifruit, bell peppers, broccoli, and Brussels sprouts.
Both vitamins are abundant in fresh, whole foods, making it easy to meet daily requirements through a balanced diet focused on fruits, vegetables, and lean proteins. Combining these foods in meals (e.g., a salmon and spinach salad with a citrus dressing) can maximize nutrient intake efficiently.
Foods rich in Carnitine
Actually, only foods from animal sources contain high amounts of carnitine. Meet, and dairy are the best sources. Adults who follow mixed diets can get about 60–180 mg of carnitine per day.
| Food Item | Carnitine (mg/100g) | Carnitine per Serving (Serving Size) | % Daily Value* (Serving) |
|---|---|---|---|
| Beef (steak) | 56–162 | 81 mg (3 oz / 85g) | ~20% |
| Pork | 24–32 | 26 mg (3 oz / 85g) | ~6.5% |
| Chicken (breast) | 3–5 | 3.6 mg (3 oz / 85g) | ~1% |
| Fish (cod) | 4–7 | 4.8 mg (3 oz / 85g) | ~1% |
| Whole Milk | 2–3 | 2.7 mg (1 cup / 240ml) | ~0.7% |
| Cheese (cheddar) | 0.6–1.1 | 0.8 mg (1 oz / 28g) | ~0.2% |
| Eggs | 0.012 | 0.01 mg (1 egg / 50g) | Negligible |
Richest Foods in Carnitine (Animal-Based)
On the contrary, vegans get only about 10–12 mg of carnitine from food per day. Vegan foods contain negligible amounts of carnitine. For instance, 2 medium slices of whole wheat bread contain only 0.2 mg, while half a cup of asparagus contains only 0.1 mg of carnitine.
| Food Item | Carnitine (mg/100g) | Carnitine per Serving (Serving Size) | % Daily Value* (Serving) |
|---|---|---|---|
| Avocado | 2 | 3 mg (1 medium / 200g) | ~0.7% |
| Asparagus | 0.2 | 0.1 mg (1/2 cup / 90g) | Negligible |
| Tempeh | 0.1 | 0.2 mg (1/2 cup / 85g) | Negligible |
| Whole Wheat Bread | 0.03 | 0.07 mg (1 slice / 30g) | Negligible |
| Peanut Butter | 0.1 | 0.1 mg (1 tbsp / 16g) | Negligible |
Vegan Sources of Carnitine
Do people who follow the Mediterranean Diet get enough?
In a modern Western diet, people primarily obtain carnitine from red meat. Processed meats and dairy also contribute, though in smaller amounts. The reliance on meat-heavy meals in Western eating habits typically ensures sufficient carnitine intake for non-vegans.
In contrast, the traditional Mediterranean diet historically included moderate amounts of red meat, consumed infrequently. Instead, fish, poultry, legumes, and plant-based foods were emphasized.
This meant Mediterranean populations relied more on endogenous carnitine synthesis (from amino acids lysine and methionine) supported by nutrient-rich foods like beans, nuts, and leafy greens that provide precursors or cofactors for synthesis, such as vitamin C, niacin, and iron.
How much Carnitine from Supplements for Weight Loss?
Carnitine is promoted as a dietary supplement for faster weight loss. But, healthy people who follow a well-balanced diet don’t need to take carnitine supplements. The body can synthesize enough carnitine. Furthermore, we can get high doses from food.
In most cases, high doses of carnitine from supplements won’t help you lose significantly more weight. On the contrary, a calorie-deficient diet and moderate exercise have a much higher impact on your body composition.
Certainly, you should consult your healthcare provider before taking carnitine supplements. Daily carnitine doses higher than 3,000 mg may cause side effects, such as nausea, vomiting, abdominal cramps, diarrhea, and bad body odor.
Also, keep in mind that we absorb about 54-86% of L-carnitine from food, as compared to only 5%-25% from oral supplements.[7]
Typical Dosage
The recommended dose for carnitine supplementation varies depending on your goals and needs:
- General Support: 500–1,000 mg per day. When I take carnitine supplementation, I prefer the lowest dose of 500 mg.
- Athletic Performance: 1,000–2,000 mg per day, sometimes divided into two doses.
- Weight Loss or Fat Metabolism: 1,500–2,000 mg per day may help optimize fat utilization, especially if paired with regular exercise.
- Medical Conditions (e.g., Deficiency): Up to 3,000 mg per day, under medical supervision.
Timing and Frequency
Carnitine can be taken daily. Long-term use is generally considered safe within the recommended dosage range.
Carnitine is best taken with meals because it enhances absorption, especially when consumed with carbohydrates. For athletes, taking carnitine 30–60 minutes before exercise might enhance its performance-related benefits.
A morning dose at breakfast can also help boost energy levels for the day.
Combining carnitine with a meal, particularly one containing carbohydrates, has been shown to enhance its uptake in the body. If you prefer to take it on an empty stomach, monitor for any gastrointestinal discomfort, as some people may experience mild side effects like nausea.
Tips
If taking higher amounts (e.g., 2,000–3,000 mg), split the dose into two servings, such as morning and afternoon, to enhance absorption and reduce the likelihood of side effects.
For best results, take carnitine consistently at the same time each day, especially if targeting fat metabolism or endurance improvements.
Drink plenty of water, especially if using carnitine to support athletic performance.
How to choose the Best Carnitine Supplement?
L-Carnitine: The most common form for general energy support, weight management, and exercise recovery.
L-Carnitine L-Tartrate (LCLT): Often used for athletic performance and recovery, as it is absorbed quickly.
Acetyl-L-Carnitine (ALCAR): Ideal for cognitive health and focus, as it crosses the blood-brain barrier and may improve mental clarity.
Propionyl-L-Carnitine: Used for cardiovascular health and improving blood flow.
For general energy and fitness, L-carnitine or LCLT are best. For brain health, ALCAR is a better option.
Look for supplements labeled as “free-form L-carnitine” or “USP-grade” to ensure purity. Avoid products with unnecessary fillers, artificial additives, or allergens. Also, check for third-party testing or certifications (e.g., NSF, GMP) for quality assurance and check the label for allergens like soy, gluten, or artificial dyes.
Who should benefit from Carnitine Supplementation?
Carnitine supplementation is most beneficial for individuals with specific medical or dietary conditions, including:
- Carnitine Deficiency: This can occur due to genetic disorders, chronic kidney disease, or certain metabolic conditions where the body cannot produce or retain enough carnitine.
- Elderly Individuals: Aging reduces the body’s ability to synthesize and absorb carnitine, potentially leading to deficiencies. Vegans, especially elderly ones, are at higher risk of deficiency.
- People with Liver or Kidney Disorders: These organs play a crucial role in carnitine synthesis and metabolism.
Carnitine is key in transporting fatty acids into mitochondria, where they are burned for energy. While this is crucial for fat metabolism, studies on carnitine supplementation for weight loss have shown mixed results. Certainly, carnitine is not a magic solution and should be combined with a healthy diet and exercise.
Vegans
Vegans and individuals following plant-based diets, such as the Mediterranean diet, might benefit from carnitine supplementation in certain situations.
Since carnitine is primarily found in animal-based foods, individuals on plant-based diets might have lower levels, especially if their endogenous production is insufficient. Although the body can synthesize carnitine from amino acids (lysine and methionine) with the help of nutrients like vitamin C, iron, and niacin, deficiencies can still arise if these precursors or cofactors are lacking.
Individuals who experience fatigue, low energy, or prolonged recovery times after exercise may benefit from supplementation. Since carnitine helps transport fatty acids into mitochondria for energy production, low levels could impair this process, particularly during periods of increased energy demand.
Vegans and those on plant-based Mediterranean diets who engage in endurance sports or intense physical activity may benefit from carnitine supplementation. Research suggests carnitine may improve exercise performance and reduce muscle soreness by enhancing fat metabolism and minimizing oxidative damage.
Is It necessary in the Mediterranean Diet?
For most healthy individuals following a balanced plant-based Mediterranean diet, the body’s endogenous production of carnitine is typically sufficient. Consuming foods rich in lysine, methionine, and supporting cofactors—such as legumes, nuts, seeds, whole grains, and leafy greens—can help maintain adequate carnitine levels.
However, supplementation may be considered if signs of deficiency or specific needs arise, such as high energy demands or recovery challenges.
Dangers & Long-Term Side Effects of Carnitine Supplementation
While carnitine supplementation is generally safe for most people when taken in recommended doses, long-term or excessive use can pose some risks.
Common side effects include nausea, stomach upset, diarrhea, and abdominal cramps. These are usually mild and subside when the dosage is adjusted or taken with food.
Also, high doses of carnitine can lead to a fishy body odor due to the production of trimethylamine (TMA) in the gut.
Carnitine supplementation can increase the production of trimethylamine N-oxide (TMAO) by gut bacteria. High TMAO levels have been linked to an increased risk of cardiovascular disease, although the direct impact of carnitine supplementation on heart health remains debated. This risk may be higher in people who already consume a high amount of red meat, as it also contributes to TMAO production.[12,13]
Long-term or excessive supplementation may place added stress on the kidneys, particularly in individuals with pre-existing kidney conditions.
Moreover, excessive reliance on carnitine supplements might disrupt the body’s natural production of carnitine, especially if used for extended periods without breaks.
Cycling carnitine supplementation (e.g., taking breaks after a few months of use) can help avoid potential dependency or metabolic imbalance.
As always, consulting with a healthcare professional before starting carnitine supplementation is advisable to ensure it aligns with individual dietary and health requirements.
Long-term use should always be weighed against potential risks. Regular blood work and consultations with a healthcare provider can ensure safe and effective use.