Acetyl-L-carnitine: Benefits, Uses, Dosage, and Side Effects

Whether your goal is to stay mentally sharp or physically fit, this nootropic can boost brain health through improved metabolism.

Acetyl-L-carnitine: Benefits, Uses, Dosage, and Side Effects

Acetyl-L-carnitine is both a dietary supplement and a substrate for metabolic reactions. It plays a crucial role in fatty acid breakdown and glucose uptake.

This exciting molecule has proven to be a significant building block in improving the human brain and helping people burn stubborn fats.

Its therapeutic properties can make a world of difference, helping you smash your exercise goals or increasing your focus at work. But selecting an effective brain-boosting supplement is not an easy task, especially with half-baked information.


    What is Acetyl-L-carnitine (ALCAR)?

    Acetyl-L-carnitine (ALC or ALCAR) is an amino acid that generates energy in your cells and supports your brain function. It is the acetylated form of L-carnitine, which can be derived from amino acids lysine and methionine.

    ALCAR breaks down your body’s protein and fatty acids with the help of an enzyme called Carnitine acetyltransferase (1). The significant health benefit of ALCAR lies in the fact that it can be converted into Carnitine, the most active form.

    The body uses this substance to transport fatty acids into the mitochondria, where they are broken down. So, in simpler terms, the more ALCAR you have, the more the fat metabolism increases.

    This usually happens in different parts of your body, including the brain and kidney. ALCAR is more soluble than L-carnitine as it quickly moves between the blood and brain. It also initiates the production of L-carnitine across cell membranes when it can’t move on its own.

    Acetyl-L-carnitine is originally made in your liver and kidneys before being circulated to other tissues like the brain and heart. It is used to improve memory, cognitive functions and stimulate fatty acid oxidation in the body simultaneously.

    For people who have had a hard time losing fat, or those trying to keep to safe blood pressure, ALCAR helps keep Carnitine levels optimal. This will, in turn, help in transporting fatty acids to where they are needed.

    Different Types

    Both ALCAR and L-carnitine come from a big compound called Carnitine, an amino acid derivative. However, L-carnitine is a more common form of Carnitine, present in both the body and Carnitine supplements.

    All forms typically have similar benefits. Other types are:

    • D-carnitine: This is the mirror image of L-carnitine. It is dangerous to the body as it prevents the absorption of other types of Carnitine. You may call it the unwelcome cousin and nemesis of Acetyl-L-carnitine metabolism. It will cause a fall in acetylcholine levels.
    • L-carnitine L-tartrate: Athletes usually use this type as a sports supplement, and of all the Carnitine supplements, it is most suited for exercise and fitness. Experts suggest that it could be used in reducing muscle soreness and promoting recovery.
    • Propionyl-L-carnitine: Popularly used to reduce pain, Propionyl-L-carnitine can cure rheumatism and maintain a healthy heart. It releases a potent enzyme called nitric oxide, which dilates your blood vessels and reduces the risks of high blood pressure. It also maintains a steady flow of blood into your heart muscles and veins.
    • Acetyl-L-carnitine: ALCAR may protect the nervous system, and this is essential in maximizing overall brain function. Studies have shown that this amino acid is linked to neurology. This form of Carnitine can cross the blood-brain barrier, hence its nootropic effects. Increased Carnitine levels impact the central nervous system and are indicated in cases of neurodegenerative diseases.

    How Does Acetyl-L-carnitine Work?

    When hours of exercise seem not to pay off, it may be time for a bit of reflection. One of the reasons you’re not losing any weight and feel mentally exhausted when you exercise is because your body uses glucose instead of converting fatty acids to energy. That’s where ALCAR comes in.

    ALCAR boosts Acetylcholine, which is an essential molecule in a process called the Krebs cycle. This process directly relates to the efficacy of energy production (2).

    The most critical compound in the Krebs cycle is acetyl-CoA. This is because the metabolic cycle yields energy in the form of ATP when AcetylCoA is deacetylated.

    Acetyl-L-carnitine plays an integral part in this by donating the acetyl moiety to a lone CoA molecule. Hence. When ALCAR and CoA meet, acetyl-CoA is formed.

    This is the moment when enters the Krebs cycle to produce tonnes of energy. Apart from its direct activity with AcetylCoA, ALCAR can also be converted to Carnitine by deacetylation.

    Carnitine, in turn, works closely with the enzyme acetyl-CoA to maintain the fatty acid levels inside and outside the mitochondria. Thus, the moiety also becomes a willing acetyl group donor and recipient.

    As a result, the coenzyme is recycled repeatedly, yielding more Acetylcholine, causing you to burn fat into brain energy.

    Even in small amounts, Acetyl-L-carnitine can move through the blood-brain barrier. This automatically connects it with the millions of mitochondria in your brain, where it exerts its beneficial effects.

    Not only does Acetylcholine result in energy production, but it also is the most prominent neurotransmitter of the parasympathetic nervous system. Therefore, an abundance of Acetylcholine is required for swift communication between the nerves in your brain and fast, sharp thinking.

    When Acetyl-L-carnitine meets choline to produce Acetylcholine, your brain cells rejoice. Thankfully, this fantastic feature makes ALCAR popular as a nootropic supplement.

    In summary, Acetyl-L-carnitine supplementation helps your body make use of its resources in the best way possible. ALCAR tells your cells to metabolize fat, optimizes your brain capacity, and increases your mental focus. It also boosts the energy in your brain while lowering inflammation and fixing blood flow.

    What Are The Benefits of Acetyl-L-carnitine?

    Research shows that Acetyl Carnitine has thousands of positive effects on the brain, bodybuilding, and weight loss.

    In addition, it improves heart health, mood and protects the brain from dangerous toxins, which may help treat some kinds of depression and other health conditions.

    The benefits of Acetyl-L-carnitine (ALCAR) include:

    Boosts Mental and Physical Energy

    A recent study of about 100 older adults who took the Acetyl-L-carnitine showed some benefit in:

    • Physical strength after exercising and decreased chronic fatigue by 51%
    • Reduction in muscle pain by 27%
    • Sleeping patterns by 28%

    Surprisingly, taking ALCAR boosts energy production and puts them in a better mood without any side effects (3). It also helped to reduce brain fatigue which in turn increased mental energy.

    Since L-carnitine supplements help with mitochondrial function, and the mitochondria are the powerhouse of every cell. Research proves that Carnitine supplementation will produce sufficient amounts of energy and reduce fatigue.

    This means better oxygen supply to muscles, the brain and less oxidative damage to your organs. This is the reason behind its ability to boost mental capacity.

    ALCAR also enhances exercise performance. It provides the mental capacity to do more and helps muscles to handle the extra work.

    With ALCAR, blood circulation to muscles is optimized, taking lactic acid away from cells and feeding them with oxygen. This means you recover faster from muscle soreness and become ready for another repetition.

    Enhances Cognitive Performance

    Carnitine supplements enhance mental focus and combat mild cognitive impairment, especially in people with mental disorders such as ADHD or brain fog. When consumed, it helps the brain think harder, for longer, and clear up the clutter in the head.

    It is also armed against geriatric depression and anxiety. An analysis shows that when the elderly are administered L-carnitine, especially by oral supplementation, they show improved mood and less cognitive decline (4).

    Various studies showed improvements in older people’s cognition and proved that it might treat age-related cognitive decline.

    In addition, several studies have shown significant improvements in overall brain function. This manifests as an improved attention span and greater focus, as well as better memory retention.

    Has Brain-protective Effects

    Acetyl-L-carnitine has also tremendously reduced pain and increased healthy nerves in a recent study of 2000 neuropathy patients.

    A study conducted on 14 people showed that 8 of them successfully became dementia-free and doubled their cognitive skills by taking a dose of the acetyl form.

    Carnitine supplementation, especially in the elderly, has proved to lessen the blow caused by oxidative stress. Adults witness better nerve function and memory, even with short-term Carnitine therapy.

    Older people who took ALCAR every day noticed a striking difference in their energy levels and general improvement in their brain health.

    With improved memory and markers of learning, studies proved that people with mild Alzheimer’s disease also saw the supplement’s benefits (5).

    According to one study, the supplement can reverse a decline in brain function seen in Alzheimer’s. In addition, clinical trials have proved that even in patients without Alzheimer’s, there was a great improvement in brain function on taking Acetyl-L-carnitine.

    Retards Peripheral Neurodegeneration

    Neurons and nerves in the body detect any chemical change in the body. Some medical conditions may cause nerve damage, and this damage can come as pain and numb limbs.

    A specific disease that damages nerves is diabetes. Not only does Carnitine encourage glucose metabolism in diabetics, but it also prevents peripheral nerves from getting ruined. This retains the ability to move and feel.

    One of the potential benefits of ALCAR is its neuroprotective effect on the nerves of your hands and feet. However, more research has to be done to produce evidence of its therapeutic effects.

    For now, we know that Acetyl-L-carnitine is a remedy for diabetic neuropathy, the nerve damage commonly associated with type 2 diabetes.

    In about six medical researches conducted using 711 patients, ALCAR protects the body against harmful blood sugar levels (6). It also reduces pain in people living with diabetes and bipolar disorder.

    Also, anti-HIV drugs cause nerve damage, called antiretroviral toxic neuropathy. However, 2-3 g of ALCAR every day can reverse nerve damage and relieve pain in patients. Therefore, for prolonged sensation in limbs, even at old age, implement a daily dose of ALCAR.

    Promotes Weight Loss

    Your body can skillfully produce glucose and adenosine triphosphate (ATP), the energy currency of living things, from anything, even proteins.

    However, the main aim of weight loss is to burn fat and increase exercise performance. Usually, the objective is to target areas like below the navel and underarms, where long-chain fatty acids have made their home.

    Stubborn fat is also an obstacle to bodybuilders as they need to convert the excess weight to muscle. More still, science tells us that fat places us at risk of heart diseases such as multiple sclerosis.

    The best way to decrease them is to use them up. They can be absorbed by cells and even boost effectiveness and work rate.

    Acetyl-L-carnitine is a known supplement in improving weight loss and enhancing physical performance by promoting metabolic glucose.

    According to a recent study, taking L-carnitine supplements increases physical performance, quickens recovery, promotes fat burning and muscle turnover (7).

    Nevertheless, these effects may not cover overweight people, people with kidney disorders, or lack of Carnitine, even at standard dose.

    Improves Circulation

    In healthy adults, ALCAR improves blood circulation as well as nutrient flow in most people after meals. Its function is necessary for a healthy brain and muscle and the prevention of heart disease.

    During research on the effects of ALCAR supplements on heart diseases, it was discovered that drug treatment containing this class of amino acids could drop systolic blood pressure by 10 points.

    High systolic blood pressure is indicative of heart disease and poor blood flow.

    Helps With Symptoms of Depression

    ALCAR aids the muscles and nerves with strength and ignites the brain with a neurotransmitter to minimize depressive symptoms. Some of these transmitters are Acetylcholine, GABA, and glutamate.

    These transmitters are directly involved in mood determination and your happiness meter. It also enhances the myelin around the brain cells and aids their growth.

    This means that you can feel more emotions and sensations instead of the bleak insensitivity that comes with depression and stress.

    Research including 791 people showed that ALCAR reduced their depression symptoms. Two other studies came to the same conclusion as well.

    One of them said that supplementing Carnitine in older people’s diet helps especially people affected by antidepressants. These effects are better noticed with long-term use (6).

    Supports Fertility and Sexual Function

    In some recent clinical trials, a group of doctors examined more than 800 infertile men with carnitine deficiency and erectile dysfunction.

    Eventually, they took a mixture of L-carnitine and Acetyl-L-carnitine. The results showed that the chances of them impregnating a woman quadrupled.

    Another clinical trial in about 120 older adults showed that taking Acetyl Carnitine, 2 grams daily for half a year, improved sexual function and testosterone levels.

    ALCAR supplements slow male aging and delay sexual dysfunction. In addition, Acetyl-L-carnitine may restore erectile function when in combination with healthy nutrition and positive sexual habits.

    More studies show that women who experienced irregular monthly cycles increased sex hormones and improved sex life.

    How To Take Acetyl-L-carnitine?

    Acetyl-L-carnitine is one of the best substances you can introduce to your stack. ALCAR is available in different forms like powder, tablets, and capsules, tested for safety and is satisfactorily tolerated.

    Studies have shown that most people absorb the drug more when taken on an empty stomach. Apart from the supplements, L-carnitine can also be found in foods containing protein.


    For people who want to improve their cognitive function, 1-4 g of Acetyl-L-carnitine per day is recommended.

    Take 2-3 g of ALCAR per day to get rid of mental fatigue and mood swings. To boost your memory, use 1-2 g of ALCAR daily. Ensure it is divided into two doses, half in the morning and a half at night.

    ALCAR should be taken without food but with water. Despite this fact, manufacturers advise you to take this dietary supplement with meals. To stay on the safer side, do not exceed 2 grams.

    Typically, ALCAR levels reach their peak about 30-60 minutes after administration. But the duration of action is much longer, and it takes about 12 hours for ALCAR levels to fall back to baseline.

    For faster absorption, ALCAR can be taken in a liquid form.

    Does Acetyl-L-carnitine Have Side Effects?

    No drug is without its potential risks. Although ALCAR is safe for people like most supplements, you shouldn’t be alarmed if you notice these side effects. They include:

    • Stomach upset
    • Nausea or vomiting
    • Headache
    • Dry mouth
    • Restlessness

    L-carnitine supplements are contraindicated in cancer patients. Don’t take ALCAR if you suffer from nerve damage caused by cancer treatment. This is because Acetyl L-carnitine may worsen the pain that the chemotherapy drugs cause.

    Avoid taking the L-carnitine supplement if you are living with hypothyroidism because Acetyl-L-carnitine may compromise the thyroid hormone.

    Lastly, visit your doctor and ask if you should begin Acetyl-L-carnitine if you’re pregnant, especially in the early stages, or have children.


    Taking ALCAR is an excellent gift you can give to your brain and entire body. It boosts cognitive levels, but it also reduces stress in the brain, helps muscle recovery and slows down aging.

    Acetyl-L-carnitine is the comprehensive nootropic agent to boost your workout gains and think ability.

    Use this nootropic to get the best out of your work and exercise hours. But keep in mind that you have to avoid it if you are treating cancer or hypothyroidism.