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Creatine vs L-Carnitine: Key Differences and Unique Benefits

Phil White


Creatine and L-carnitine (aka carnitine) are both amino acids–the building blocks of protein.

People often take creatine to improve muscle performance and carnitine to support brain function, but the effectiveness of both supplements extends beyond these primary uses.

In this article, you’ll learn some of the additional ways that you can benefit from creatine and carnitine, the differences between them, and which is best for you.

Creatine Overview

Creatine is naturally produced in the human body by the interaction of the amino acids arginine, glycine, and methionine. It’s the main component of phosphocreatine, which is used to recycle ATP in cells.

The ATP-PC energy system provides fuel for fast, powerful bursts of activity during high-intensity exercise. ATP also supports key functions like muscle movement and nerve cell growth.

Some of the key benefits of creatine include:

  • Improves muscular endurance and recovery

  • Supports optimal muscle function

  • Increases strength and power output

  • Boosts energy levels and decreases recovery time

  • Improves cognition

Carnitine Overview

Found in most cells in the human body, carnitine is a naturally occurring amino acid that supports brain function and energy production. It facilitates the transport of fatty acids into mitochondria (the power plants of cells), where they are turned into energy. Carnitine protects brain cells from the damage that can be caused by oxidative stress.

The advantages carnitine provides include:

  • Increases memory, focus, and cognition

  • Boosts energy production

  • Improves mood 

Creatine vs Carnitine: The Key Differences

Key Benefits




High-intensity training, improved recovery, cognitive function

Increases maximal oxygen uptake


Creatine Monohydrate

Acetyl L-Carnitine


3-5g daily

1 x 500mg capsule

Onset Time

2-4 weeks

2-4 weeks

Cycling and Loading

No cycling or loading needed

No cycling or loading needed

Side Effects

No known side effects

No known side effects

Best for

Speed, strength, and power training; maintaining cognitive output under stress

Improving fat metabolism and increasing mental focus and clarity

From a physical perspective, creatine is considered to be the most effective supplement for “increasing high-intensity exercise capacity and lean body mass during training.” Research has also shown that creatine also improves recovery after training and allows athletes to get back to peak strength and power production faster.

In contrast, carnitine provides long-lasting fuel for consistent output by transporting fatty acids to the cells that need them for energy. It has been found to increase maximal oxygen uptake—which might increase endurance performance—and could also enhance recovery from fatigue and musculoskeletal injury.

While 95% of creatine in the body is found in skeletal muscle, more recent research has highlighted the important role of the quantity located in the brain. One review stated that “Oral creatine administration may improve short-term memory and intelligence/reasoning of healthy individuals” and could support cognition among aging and stressed people.

This is backed up by another study on brain function, which found that “creatine is most likely to exert an influence in situations whereby cognitive processes are stressed.” A review  suggested that creatine supplementation might also help the brain recover from trauma and shows promise for combating age-related cognitive decline.

Carnitine can also support brain function, but in different ways. A formula containing carnitine helped elderly participants improve their working and episodic memory. Another trial found that carnitine levels are reduced in the brains of people with severe depression. Carnitine is vital for supplying the brain with energy by facilitating fatty acid transfer to cells and might also play a role in mood regulation. 

An additional study concluded that carnitine supplementation “significantly decreased the attention problems and aggressive behavior in boys with ADHD.” 


There are many forms of creatine supplements on the market, each claiming to be the most effective. However, the International Society of Sports Nutrition wrote that “Creatine monohydrate is the most extensively studied and clinically effective form of creatine for use in nutritional supplements.”

Carnitine supplements can also be found in various forms, but a study published in Frontiers in Bioscience found that acetyl L-carnitine is easily absorbed and reduces inflammation, supports fat metabolism and “exerts neuroprotective, neurotrophic, antidepressive and analgesic effects.”


The optimal dosage for creatine is three to five grams daily. Taking a single 500mg capsule of carnitine every day is adequate.

Onset Time

It will take around two to four weeks to start seeing the benefits of both creatine and carnitine, with the average onset time of 14 days. For optimal benefits, continue using both these supplements for an extended period.

Cycling and Loading

Early research suggested that loading creatine at a total of 25 grams per day (split into five servings) for a week followed by reducing the dosage to five grams a day thereafter was the most effective protocol. However, a study published in the Journal of the International Society of Sports Nutrition concluded that you do not have to load creatine. “Lower, daily doses of creatine supplementation (i.e. 3-5 g/day) are effective for increasing intramuscular creatine stores, muscle accretion and muscle performance/recovery.”

It’s also unnecessary to cycle off creatine because your body won’t build up tolerance to it. No loading or cycling is needed with carnitine supplementation either.

Side Effects

Research demonstrates that the side effects of carnitine supplementation are few and minimal. A review conducted by a team of Polish exercise scientists noted that “Carnitine preparations administered orally can occasionally cause heart-burn or dyspepsia.” However, they went on to give multiple examples of multiple populations taking carnitine for extended periods with no adverse effects. This review concluded that “intakes up to 2 g/day are safe for chronic supplementation.”

An International Olympic Committee (IOC) statement on dietary supplements for high-performance athletes stated that “No negative health effects are noted with long-term use” of creatine. The only athletes who it might adversely impact are those who compete in certain weight categories, as creatine supplementation typically increases body mass.

There are anecdotes suggesting that creatine has other side effects. However, these haven’t been confirmed in a clinical setting. “Isolated reports suggest creatine may be associated with various side effects affecting several organ systems including skeletal muscle, the kidney and the gastrointestinal tract,” stated a review in Sub-Cellular Biochemistry . “The majority of clinical studies fail to find an increased incidence of side effects with creatine supplementation.”

Best For

While creatine is best for supporting speed, strength, and power training sessions, helping you recover from them, and maintaining cognitive output while under stress, a carnitine supplement can help you improve fat metabolism and increase mental focus and clarity .

Creatine and Carnitine: Two Different Ways to Power Your Workouts

Research has shown that creatine and carnitine can both support physical performance in different yet complementary ways:

How Creatine Boosts Muscle Power

How Carnitine Enhances Energy and Recovery

How Safe Are These Supplements?

Creatine is one of the most widely studied supplements on the market, with decades of clinical research to demonstrate its effectiveness and safety. “Studies show that short- and long-term supplementation is safe and well tolerated in healthy individuals and in a number of patient populations,” a paper released via Current Sports Medicine Reports asserted.

While carnitine doesn’t have the same breadth of research to back its efficacy and safety as creatine does, there is still some clinical evidence for its long-term safety. A review published in Regulatory Toxicology and Pharmacology stated that “the evidence of safety is strong at intakes up to 2000mg/day l-carnitine equivalents for chronic supplementation.” The authors went on to note that taking higher levels had not shown any safety risks.

How to Incorporate Enough Creatine and Carnitine into Your Diet

Creatine is found in poultry, fish, and organ meats, but the best source is red meat such as beef and bison. However, the quantity varies, and unless you were eating a large amount of these foods consistently, it would be difficult to get a clinically effective dose of creatine to support exercise performance and recovery and cognition.

Red meat is also the best dietary source of carnitine. Dairy products, marine sources, chicken, and turkey also contain carnitine. But just as with creatine, most people’s diet would not provide enough. One study found that vegetarians have 10% lower blood plasma levels of carnitine, and that supplementation elevated this.

Taking carnitine and creatine supplements is the best way to ensure you’re getting enough of these vital amino acids to positively impact physical and cognitive performance. You can mix a scoop of creatine monohydrate powder into six to eight ounces of liquid daily, while taking a 500-milligram carnitine capsule once a day. A paper published in Nutrients concluded that taking both creatine and carnitine has a positive effect on muscle growth.

Which Is Better for You: Creatine or Carnitine?

If you want to increase strength and power, improve muscular endurance, and speed recovery, creatine is the best choice. Whereas if you’re seeking to increase your energy level, boost your mood, and improve focus and memory, carnitine might be the better option. Still not sure which to choose? Try both!

Momentous sources the gold standard monohydrate form of creatine , which NSF Certified for Sport® and Informed Sport testing proves is pure and effective.

"Saw a major difference in strength and recovery after 2 weeks."

- customer Porter G. 

“This is a great supplement of the highest quality. Been taking it for some time and feel that it helps with my energy levels, mental clarity, and body composition.”

-customer Matthew M.

Frequently Asked Questions

Can you take creatine and L-carnitine together?

You can take creatine and L-carnitine together without any side effects or reducing absorption.

Should you take L-carnitine if you’re not exercising?

You can take L-carnitine anytime, even if you’re not exercising.

Are either creatine or carnitine helpful for weight loss?

Creatine has not been shown to be helpful for weight loss, but carnitine is because it increases fat metabolism.

Does either supplement affect sleep?

Neither creatine nor carnitine have been shown to affect sleep, although some studies suggest that creatine can help maintain mental performance after inadequate rest.

Phil White

Phil White

Phil White is an Emmy-nominated writer and the author of The Leader's Mind with Jim Afremow, Unplugged with Andy Galpin and Brian Mackenzie, Waterman 2.0 with Kelly Starrett, and Game Changer with Fergus Connolly. He also co-hosts The Basketball Strong Podcast with former Lakers strength coach Tim DiFrancesco and is a frequent contributor to TrainingPeaks.