Our evidence-based analysis of Acetyl-L-Carnitine features unique references to scientific papers and anecdotal reports.

What Is Acetyl-L-Carnitine?

Acetyl-L-Carnitine (ALCAR) is a naturally-occurring micronutrient that delivers macro benefits for the human brain and body. Not only is it a powerful nootropic that can increase focus‍[1] and enhance general cognition,‍[2] ALCAR is also a potent neuroprotectant that fights physical and mental fatigue,‍[3] promotes cardiovascular health,‍[4] and helps protect against the ravages of aging.‍[5]

ALCAR is a highly bioavailable form of the lysine derivative L-carnitine, which is produced naturally by the body but can also be synthesized from animal proteins in the diet.

Unlike other forms of L-carnitine, which act primarily in the body and are typically used to enhance physical performance and alleviate blood flow issues, ALCAR readily crosses the blood-brain barrier and acts within the brain itself.‍[6]

ALCAR is a precursor of the “learning neurotransmitter,” acetylcholine,‍[7] which makes it a valuable nootropic. Also, studies indicate it influences cerebral energy metabolism by upregulating levels of noradrenaline and serotonin and decreasing levels of the inhibitory neurotransmitter GABA.‍[8]

It has also been shown to work within the brain cells themselves by helping maintain the integrity of the cellular mitochondria,‍[9] the “powerhouse” portion of the cell in which nutrients are converted to energy. Age-related deterioration of the mitochondria is associated with several disorders, including Alzheimer’s and other neurodegenerative diseases.

ALCAR is available without a prescription as a nutritional supplement.

Benefits and Effects of Acetyl-L-Carnitine

Research has proven that that ALCAR benefits both the brain and body in a surprising variety of ways, from enhancing cognitive abilities to increasing energy, reducing pain, and even preventing damage from alcohol consumption.

Cognitive Enhancer

ALCAR’s primary nootropic function is the enhancement of the acetylcholine system. It is known to be a precursor of acetylcholine, the neurotransmitter most closely associated with memory and learning. ALCAR has repeatedly been proven to improve and enhance brain function in individuals suffering from cognitive decline.

Studies show that it is particularly effective in reducing mental fatigue and enhancing cognitive function among the elderly‍[10] and improving learning ability in patients with mild cognitive impairment associated with Alzheimer’s disease.‍[11]

Its effect on cognition in otherwise healthy individuals has not been thoroughly studied, but many users report positive results.‍[12]‍[13]‍[14]

An Effective Neuroprotectant

ALCAR’s potent antioxidant properties make it a powerful neuroprotectant, capable of preventing and even repairing damage caused by free radicals that scavenge and damage brain cells.‍[15] Free radical damage is closely associated with aging and is implicated in age-related disorders, including Alzheimer’s and Parkinson’s diseases.

ALCAR also helps the brain rid itself of other toxins and is thought to reduce cell death due to excitotoxicity, a pathological process triggered by the overactivation of glutamate receptors.‍[16]

ALCAR improves the neural network by strengthening nerves and signal receptors and has even been shown to protect the brain against the harmful effects of drinking alcohol.‍[17]

Potential Treatment for Age-related Disorders

One of ALCAR’s most exciting prospects is as a treatment for age-related neurological disorders, including Alzheimer’s Disease. It has been shown to effectively slow decline in Alzheimer’s patients and reduces age-related memory loss.‍[18]

Pain Reliever

Studies and clinical trials indicate that ALCAR is a reliable pain reliever, particularly effective at reducing chronic neuropathic pain.‍[19]

In studies involving over 1770 patients with pain related to diabetic neuropathy, HIV, compression, and injury, subjects taking ALCAR saw a reduction in pain and improvement in nerve function.‍[20]

Treatment for Depression and Fatigue

ALCAR has been shown to improve both fatigue and depression in patients with chronic illnesses. It improved the chronic fatigue syndrome associated with multiple sclerosis,‍[21] and a series of randomized clinical trials indicated it was an effective antidepressant for various patients, including people with fibromyalgia, hepatic encephalopathy, and aged patients with co-morbidities that made other antidepressants impractical.‍[22]

How It Works

Like all L-carnitine variants, ALCAR is synthesized primarily in the liver and kidneys and then transported to other tissues.

ALCAR has excellent bioavailability and is readily absorbed by the gastrointestinal tract. Once absorbed, its actions differ considerably from those of other forms of L-carnitine, which don’t cross the blood-brain barrier. The acetyl groups that make ALCAR unique enable it to cross the blood-brain barrier readily and rapidly, and ALCAR’s most important functions take place in the brain.

Increased Production of Important Neurotransmitters

ALCAR is known to be a precursor for the neurotransmitter acetylcholine, which is largely responsible for learning, memory, and cognitive function.

The ability to increase levels of acetylcholine is an important part of ALCAR’s nootropic capabilities, but it’s part of its neuroprotectant capability as well; low levels of acetylcholine are strongly associated with increased risk of neurological disorders like Parkinson’s and Alzheimer’s diseases.

ALCAR has also been shown to increase levels of norepinephrine and serotonin, crucial neurotransmitters that play a major role in mood and brain function while reducing levels of the inhibitory neurotransmitter GABA.‍[23] The ability to modulate neurotransmitter production is one of the primary ways ALCAR complements nootropics like the racetams, which enhance the action of neurotransmitter receptors in the brain.

Enhanced Brain Metabolism and Neuroprotection

ALCAR also targets brain metabolism, boosting cellular energy and acting as a potent neuroprotectant.‍[24] Its significant antioxidant properties combat the effects of cellular oxidation and reduce the number of damaged cells in the brain, making ALCAR a powerful anti-aging agent.

Damaged fat cells known as lipofuscin, called “age spots” when they appear on the skin, also occur in the brain and are strongly associated with age-related neurological disorders, loss of energy, and poor memory. By helping the brain eliminate these damaged cells, ALCAR both boosts brain function and significantly reduces the risk of neurodegenerative disorders.‍[25]

It has also been shown to prevent brain deterioration during periods of stress.‍[26]

ALCAR safeguards the brain and improves cognitive function in several ways, including preserving the integrity of the cellular mitochondria and strengthening the protective myelin sheath that surrounds the nerves in the brain.‍[27] Mitochondrial breakdown is associated with several age-related disorders, including Alzheimer’s and Parkinson’s diseases, and weakening or damage to the myelin sheath has a severe adverse effect on vision, hearing, balance, coordination, and general brain function.

ALCAR has also been shown to strengthen and protect membrane signal receptors in the brain and help keep neurons healthy and functional. This protective ability not only increases the ability to form and maintain new memories but is also another way in which ALCAR complements and potentiates other nootropics.

Other Actions in the Body

ALCAR works in the body and the brain, performing many of the same functions as L-carnitine.

While the conversion of fat to energy isn’t one of ALCAR’s primary benefits, it does increase metabolic efficiency. It provides many of the same energy-related benefits as other L-carnitine variants.

ALCAR has also been shown to be particularly effective at reducing hypertension‍[28] and lowering insulin resistance.‍[29]


Recommendations for the standard daily dosage of ALCAR range from 1,000–3,000 mg daily.‍[30]

Users report that taking ALCAR in the morning provides peak daytime brain function, though some users say ALCAR works best when split into two or more doses taken at intervals throughout the day. Taking ALCAR late in the evening may result in disruption of the normal sleep cycle.‍[31]

ALCAR can be taken on an empty stomach, but users who experience gastrointestinal upset report that it can be minimized or avoided by taking ALCAR with food.‍[32]


ALCAR’s effects are truly potentiated when combined with other nootropics. It is commonly included in stacks that feature nootropics in the racetam family, allowing them to function to their fullest potential.

Since ALCAR works in tandem with the acetylcholine system, it may also be a good idea to include a choline precursor, such as Alpha GPC, in your stack.

ALCAR and Piracetam Stack

1x per day

ALCAR and Mind Lab Pro Stack

An easy and effective stack is to combine ALCAR with a preformulated nootropic blend, such as Mind Lab Pro by Opti-Nutra which contains 11 all-natural research-backed ingredients. Mind Lab Pro can serve as an excellent foundation to your stack as it is designed to improve all aspects of memory, mental performance, mood and stress resistance, maintenance, and brain repair.

For a detailed overview of its ingredients and effects, refer to our Mind Lab Pro review.

1x-2x per day

Side Effects

ALCAR is exceptionally safe and well-tolerated. There does not appear to be any toxicity associated with the standard supplemental dosages of carnitine.

Side effects are rare, and those that are reported are minor and are often associated with high dosage. Nausea, the most commonly reported side effect, can usually be addressed by taking ALCAR with food. Other side effects include headaches, dry mouth, and restlessness.

Where to Buy

ALCAR can be purchased directly from PureNootropics.net, a reliable supplier of specialty nootropic supplements.

If you prefer doing your online shopping on Amazon.com, we recommend sticking to products made by reputable brands such as NOW Foods Acetyl L-Carnitine.

Closing Thoughts

ALCAR is a remarkable natural supplement that offers a host of benefits for both the brain and body.

A powerful brain booster in its own right, it works well with other nootropics and can act as a powerful complement and potentiator. It’s safe, affordable, very well tolerated, and readily available without a prescription.

For anyone interested in better health, better cognitive abilities, and better defense against aging, ALCAR is a supplement to try.


Planning to start a new supplementation regimen? See our medical disclaimer.

This page was last updated on July 16, 2021.