Acetyl-L-Carnitine is a nonessential nutrient produced by your liver and kidneys. It helps generate energy and has antioxidant qualities to fight cell-damaging free radicals.

Your body can usually produce all the carnitine it needs, and it can convert L-carnitine to Acetyl-L-Carnitine. L-Carnitine and Acetyl-L-Carnitine are two different forms of the same amino acid.

So why bother taking ALCAR supplements if your body has you covered? 

That’s exactly what we cover here in this article. But first, a bit of background…

What is Acetyl-L-Carnitine?

Acetyl-L-carnitine is one of three types of carnitine. L-carnitine and Propionyl-L-Carnitine are the other two. All three forms of L-Carnitine promote energy, with Acetyl-L-carnitine known for improving markers of memory and learning in animals, as well as Alzheimer’s patients. [1]

Animal-based foods are good sources of Acetyl-L-Carnitine and Carnitine, including ground beef, cod, pork, milk, cheese and ice cream; avocado and whole wheat bread are good non-animal sources.

A study showed vegetarians and other individuals eating low-carnitine diets experienced better bioavailability of Acetyl-L-Carnitine from foods they ate than meat-eaters. [2]

Acetyl-L-Carnitine supplements aid biosynthesis of the neurotransmitter acetylcholine for optimal brain and nerve function.

It is used by people who have a genetic defect and can’t produce needed carnitine in the body or to treat Alzheimer’s disease, reduced cognitive function, and depression in the elderly. [3]

Supplements similar to Acetyl-L-Carnitine include Coenzyme Q10, creatine, and iron to bolster athletic performance.

All of these supplements help the body produce more energy and have antioxidant qualities. Like B-complex vitamins and SAME-e, it improves mental function and increases energy.

Acetyl-L-Carnitine is available for sale online and in retail stores throughout the U.S. and Canada. It is a favorite supplement for bodybuilders and athletes due to its ability to augment heart and brain function.

It’s available in capsule and powder form; the powder form is usually flavored and marketed for athletes.

 Safe for most adults to use, Acetyl-L-Carnitine improves energy and focus for everyone from office workers to seniors. It’s not just a supplement for athletes, even though it is often advertised as such.
Acetyl-L-Carnitine may also improve heart arrhythmia in people with poor cardiovascular health. [4]

Other Names

ALCAR,Arginate Dihydrochloride, Acetyl-L-Carnitine Arginate HCl, Acétyl-L-Carnitine Arginate HCl

Editor’s Note

Users of Acetyl-L-Carnitine (or ALCAR, as it’s often called), praise the supplement for its’ ability to improve memory.

While it is used to counteract the effect of aging on the brain, busy young people used it for increased focus and memory, including young Moms, entrepreneurs, and individuals suffering from chronic fatigue.

It has energy-boosting qualities and the ability to provide your brain with more of the substances it needs to function efficiently.

Bodybuilders who use Acetyl-L-Carnitine notice an increase in muscle definition, energy and focus. (Mental alertness is cited as the supplement’s most potent trait by most reviewers.) [5]

Students also use Acetyl-L-Carnitine to give them more focus when studying for exams.

Reviews also indicate that people with Graves disease, Lyme disease, Down’s Syndrome and cataracts have also used Acetyl-L-Carnitine with varying results

Carnitine levels decrease as we age, (or when we’re under stress), and ALCAR reduces oxidative stress. A study conducted on aged rats, and ALCAR decreased oxidative stress in the older rats brains while L-carnitine didn’t.

ALCAR has also been shown, in at least one study, to protect the brain against oxidative stress caused by HIV and certain antiretroviral drugs.

If you buy Acetyl-L-Carnitine from a reputable buyer and take the recommended dosage, you should feel more focus and clarity without the dizziness or jitters caused by some energy- enhancing supplements.

Some users advise against using Acetyl-L-Carnitine supplements manufactured in China, as they may contain non-pharmaceutical grade and potentially toxic form of ALCAR.

Always check for the country of origin when purchasing Acetyl-L-Carnitine and thoroughly read product reviews before buying. Because this is a popular supplement for fitness and bodybuilding enthusiasts, marketers tend to make grandiose claims about its effects.

Acetyl-L-Carnitine Reviews

Aside from the usual Amazon reviews about specific Acetyl-L-Carnitine, I found a few supplement and health experts with positive things to say about their experience with ALCAR in general. used Acetyl-L-Carnitine for weight loss and writes ” I clearly remember how focused and concentrated I was after my first dosage of 500 mg. Since then Acetyl-L-Carnitine always has a spot on my shelf.”

Ben Greenfield Fitness recommends Acetyl-L-Carnitine as part of two supplement stacks as an “easy and cheap bio hack.”

Benefits and effects

Cognitive Function

Acetyl-L-Carnitine has been shown to improve cognitive function, in people suffering from cognitive decline due to mood disorders. It may protect against the cerebral decline caused by Alzheimer’s disease and age-related memory loss. [6]

Alzheimer’s patients who took two or three grams of Acetyl-L-Carnitine a day for three to six months showed a slower decline in cognitive function and increased attention spans.

Acetyl-L-Carnitine enables the mitochondria in brain cells to handle significant amounts of stress without losing their ability to produce energy, which is especially relevant to older adults, although it can benefit anyone regardless of age.

Weight Loss

Carnitine transports fat into blood cells to increase metabolism and burn fat. Good for fat loss and gaining muscle, Acetyl-L-Carnitine helps boost your energy from fat deposits instead of glucose.

This increases your chance of losing weight. You can lose more weight with Acetyl-L-Carnitine and Carnitine by eating more fish and other foods containing Omega 3 fatty acids.

The highly-touted Atkins diet listed Acetyl-L-Carnitine as one of the most effective supplements for weight loss.

ALCAR supplementation pushes more fatty acids into the cells’ mitochondria, where they can be burned off, making it easier to lose weight.

Erectile Dysfunction

A double-blind study showed that elderly men with low testosterone who took two grams of Acetyl-L-Carnitine and two grams of Propionyl-L-Carnitine every day for six months had improved erectile function, and the carnitine treatment proved more effective than treatment for low testosterone levels.

ACLAR and L-Carnitine may also be indicated for the treatment of infertility and low sperm count in men, although studies on the subject are inconclusive.

Diabetic Neuropathy

An Acetyl-L-Carnitine supplement was more effective than a placebo in treating diabetic patients with nerve pain. Patients were given either 500 or 1000 mg a day for a year. [7]

Subjects showed a reduction in nerve pain and vibration perception.

How It Works

Acetyl-L-Carnitine and other types of carnitine are synthesized in the liver and kidneys and then transported to other parts of the body.

It’s absorbed by the gastrointestinal tract, and unlike other types of carnitine, it can cross the blood-brain barrier.

The neurotransmitter acetylcholine is associated with memory, cognitive function and learning. Acetyl-L-Carnitine contains an acetyl moiety, giving it the ability to improve mental function.

The absence of an appropriate amount of acetylcholine in the body puts you at a risk of brain fog, poor memory or Alzheimer’s.

ALCAR also increases the amount of mood-enhancing neurotransmitters serotonin and norepinephrine to relieve the anxiety that clouds your thinking.

When paired with L-Theanine, Inositol, or significant mood influencing nootropics, it further enhances brain function by balancing your emotions.

The myelin sheath protecting the nerves in your brain ensures optimal cognitive function. When this sheath is damaged, it causes diminished brain function, poor coordination, and problems with vision and hearing. Acetyl-L-Carnitine not only guards this sheath, but it protects neurons to help you form new memories. [8]

Acetyl-L-carnitine helps metabolize fat, which gives it traits as a potential weight loss aid. Its ability to metabolize fats also improves cognitive and nervous function.


The amount of acetyl-L-carnitine you should take daily depends on the condition you’re treating and your tolerance level.

As a general nutritional supplement, you should take between 500 to 2,000 mg a day. For better cognitive function, take one dose in the morning and two other doses at even intervals later in the day.

You can take Acetyl-L-Carnitine on an empty stomach, but if that causes stomach discomfort, you can take it with food.

Recommended Acetyl-L-Carnitine dosages for specific conditions:

  • Weight loss – 1000 to 3000 mg a day, with breakfast
  • Alzheimer’s disease- 1500 to 4000 mg a day, divided into two or three doses
  • Depression in the elderly – 1500-3000 mg per day, divided into two or three doses
  • Male infertility – one gram of Acetyl-L-Carnitine per day; use 4000 mg per day to increase sperm
  • Age-related memory loss – take 1500-2000 mg daily
  • Diabetic neuropathy (nerve malfunction) – 1500 to 3000 mg, divided into two or three doses a day

Side Effects

People taking Acetyl-L-carnitine have reported some side effects, including diarrhea, nausea, vomiting, headaches, insomnia, high blood pressure and low blood sugar (in people with diabetes) or psychosis (in people with bipolar disorder).

If you have any of the following conditions, check with your doctor before taking Acetyl-L-Carnitine, as it may cause serious complications.

  • High Blood Pressure
  • Diabetes
  • Sleep Disorders
  • Hepatitis C
  • Cirrhosis of the Liver
  • Alcoholism
  • Bipolar Disorder

If you have a history of seizures or hypothyroidism (under-active thyroid), you shouldn’t take Acetyl-L-Carnitine, as it may increase seizures or interfere with thyroid hormones.


Choline and Acetyl-L-Carnitine

Stacking choline, an energy-boosting member of the B-vitamin family with ALCAR will give you higher levels of the neurotransmitter acetylcholine, which improve memory.

Piracetam, Alpha GPC and Acetyl-L-Carnitine

Take a stack of 500 mg Acetyl-L-Carnitine, 300 mg Alpha GPC and 4.8 grams of Piracetam daily to increase energy and brain function.

Alpha GPC, an acetylcholine precursor, and form of choline, is used for learning, focus and mood improvement. It works with ALCAR to give you even better cognitive function.

Piracetam, a “Smart Drug” from the racetam family, is made from aminobutyric acid, a replica of the neurotransmitter GABA to improve neurotransmitter actions and reduce anxiety.

Acetyl-L-Carnitine and Ashwagandha

Ashwagandha, an Ayurvedic herb used to treat stress and lack of focus, is an acetylcholinesterase inhibitor that stops acetylcholine from breaking down in the brain.

To enhance brain function and remain calm while energized, try 500 mg of Ashwagandha and 300 mg of Acetyl-L-Carnitine.

Acetyl-L-Carnitine Alternatives

Alpha Lipoic Acid (ALA)

Alpha Lipoic Acid or (ALA) is a fatty acid is produced by your body. An antioxidant found in all your cells, it transforms glucose into energy and fights free radicals that damage your tissues and cause inflammation.

It improves brain function and helps prevent cell damage, and may help treat Type 2 diabetes and nerve damage. Although it’s referred to as ALA, it is different from the Omega 3- fatty acid, alpha linolenic acid, that’s also called ALA.

Acetyl-L-Carnitine vs. Alpha Lipoic Acid Comparison:

  • Both supplements work in your cells’ energy center, the mitochondria. ALCAR benefits the brain by improving the function of the mitochondria, while Alpha Lipoic Acid is a naturally occurring compound created in the mitochondria.
  • Alpha Lipoic Acid has potent antioxidant properties to fight free radicals, while ALCAR fight free radicals, Alpha Lipoic Acid Antioxidant properties appear to be stronger.
  • Alpha Lipoic Acid and Acetyl L-Carnitine promote brain function, but ALCAR also offers fat-burning potential for weight loss and promotes heart health


L-Arginine is a nonessential amino acid synthesized in the body. It has few side effects and breaks down proteins.

It helps promote vascular and heart health by relaxing blood vessels, which helps with clogged arteries and angina.

Acetyl-L-Carnitine Vs. L-Arginine Comparison

  • Both L-Arginine and Acetyl-L-Carnitine supplements offer protection for heart health, but L-Arginine’s major advantage is increasing blood flow, while Acetyl-L-Carnitine has been used to correct heart arrhythmia.
  • Both supplements are used to treat erectile dysfunction, but due to its ability to improve blood flow, L-Arginine is the preferred treatment for this condition.
  • L-Arginine has been shown to improve high blood pressure, but a study showed Acetyl-L-Carnitine reduced systolic blood pressure by nine mmH.


An amino acid used to synthesize proteins. L-Tyrosine is essential for producing important neurotransmitters, including dopamine, epinephrine, and norepinephrine.

Because L-Tyrosine is critical to producing the neurotransmitters epinephrine and norepinephrine, a low level of L-Tyrosine may cause poor memory and cognitive function when you’re under stress.

Acetyl-L-Carnitine Vs. L-Tyrosine Comparison:

  • Supplemental L-Tyrosine improves energy by replenishing dopamine, norepinephrine, and epinephrine. Acetyl-L-Carnitine works by transporting lipids and fatty acids into your mitochondria, which encourages weight loss and better mental performance.
  • Studies indicate L-Tyrosine supplement may make you more alert after insomnia or sleep deprivation.
  • L-Tyrosine is not shown to treat depression, heart problems, or athletic performance. Acetyl-L-Carnitine does have some effect on mood and cardiovascular issues.

Closing Thoughts

Acetyl L-Carnitine, either alone or with an L-Carnitine supplement, is best used for cognitive function and increased energy.

Research has shown that it may be helpful for may types of age-related cognitive decline, from the normal mental degeneration experienced by many people to Alzheimer’s disease.

As long as you choose a safe supplement brand, Acetyl L-Carnitine has few side effects and little to no chance of toxicity.

While not a prime supplement for weight loss, Acetyl L-Carnitine increases metabolism and burn fat, so it may work with other supplements (along with diet and exercise).

Additional Resources

More on taking Acetyl-L-Carnitine
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