1.About L Carnitine/ALCAR/PLC

2.Acetyl l Carnitine For Brain Health- Neuroprotective, Helps Repair Myelin, Improves Memory, Fights Inflammation and Depression and Helps Correct Neurotransmitter Deficiencies

3.More Acetyl L Carnitine Benefits- ALCAR Improves Mitochondrial Health

4.More Acetyl L Carnitine Benefits- ALCAR Improves Sleep and Decreases Fatigue

5.More Acetyl L Carnitine Benefits: ALCAR, Sex Hormones & Reproduction

6.More Acetyl L Carnitine Benefits: L Carnitine/ALCAR For Heart Health

7.More Acetyl L Carnitine Benefits: L Carnitine/ALCAR For Weight Loss, Muscle Growth and Fitness

8.More Acetyl L Carnitine Benefits: L Carnitine/ALCAR & Sugar Metabolism

9.Acetyl L Carnitine Side Effects

10.Other Ways To Increase Boost L Carnitine/ALCAR Levels: Diet and Exercise

1.About L Carnitine/ALCAR/PLC

L carnitine is a small water-soluble, vitamin-like molecule that plays a huge role in normal physiology and very important for brain health. It is found in abundance in the liver, skeletal muscle, heart, brain and testis. N-acetyl-L-carnitine (ALCAR), propionyl-L-carnitine (PLC) and L-carnitine (LC) are three forms of the naturally occurring amino acid carnitine and are also available in supplement form. How do you know which form to choose ? PLC works the best if your goal is to lose body fat as it helps the body convert fat into energy; it is also great for muscle and heart health. Your brain prefers ALCAR form, which is used for the synthesis of acetylcholine. ALCAR crosses easily the blood brain barrier (BBB), supporting brain and nerve health. ALCAR also helps convert fat into energy, but to a lesser degree than l carnitine. A combination of PLC and ALCAR seems to be ideal if you are looking to boost the sex hormones naturally.

2. ALCAR & Brain Health: ALCAR offers neuroprotection, helps repair myelin, improves memory, fights inflammation and depression and helps correct neurotransmitter deficiencies. This makes ALCAR a great choice for managing MS and other neurological conditions. 

ALCAR was studied for managing different brain conditions- from brain injuries to MS, Alzheimer’s, Parkinson’s or simply to enhance memory in healthy individuals [1]. ALCAR can be used by brain cells as a source of energy, a precursor of acetylcholine, helping modulate GABA pathways and combat stress. It can be also incorporated into fats for myelination and cell growth [2],[3].

ALCAR helps promotes healthy levels of neurotransmitters. The ALCAR- dopamine link: ALCAR supplementation increases not only acetylcholine and GABA levels, but also increases dopamine, and protects the dopamine producing neurons against damage — at least in animal models. ALCAR can also raise serotonin and norepinephrine levels [4],[5],[6].

ALCAR can help decrease brain inflammation and has strong antidepressant qualities [7]. Its antidepressant effects had been researched in randomized controlled studies, which found this supplement to be as effective as SSRI drug fluoxetine [8].

ALCAR nootropic? Yes, ALCAR is a nootropic (aka smart drug/supplement), as it helps boost cognitive function. As a precursor of acetylcholine, ALCAR  improves memory and the connection between neurons (working on both synaptic morphology and synaptic transmission. It has antioxidant qualities and prevents neuron death, and age related memory impairments [9].

3.More Acetyl L Carnitine Benefits- ALCAR Improves Mitochondrial Health : By supporting healthy mitochondria [10], ALCAR can help fight free radicals, inflammation and manage increased permeability of the blood brain barrier (neurodegeneration and brain inflammation are both linked with increased BBB barrier). It also appears to have anti-seizure activity [11].

Technical: ALCAR is required for the transport of long-chain fatty acids into the mitochondria for ß-oxidation, ATP production, and removal of excess short- and medium-chained fatty acids , and thus helps to maintain efficient mitochondrial function [36].

4.More Acetyl l carnitine Benefits- ALCAR can Help Improve Sleep and Decrease Fatigue : ALCAR showed some improvement in decreasing fatigue associated with RR-MS, but less effective than the prescription drug amantadine [12]. L carnitine can be helpful to manage sleep apnea, especially when combined with other antioxidant nutrients [13].

5.More Acetyl L Carnitine Benefits: ALCAR, Sex Hormones & Reproduction

A combination of ALCAR and PLC was found to be more effective yet safer than testosterone replacement therapy based on a randomized controlled study conducted in men age 60-74. Unlike testosterone therapy, carnitine supplements did not increase the size of the prostate, but showed many benefits- antidepressant, anti fatigue, boosting sex drive and sexual desire [14]. Carnitine (PLC) seems to work well in combination with Viagra in cases of ED and diabetes [15]. The benefits of L carnitine to treat male infertility are very well documented, as was found to improve the quality and motility of the sperm.

Technical:. L carnitine promotes epididymal maturation of spermatozoa. It serves as an intra-mitochondrial vehicle for the acyl group, which in the form of acyl-CoA works as a substrate for the oxidative reactions, producing energy for sperm respiration and motility [16].

L carnitine/ALCAR is by far, one of the most effective and safe supplements for treating female infertility as well. To be more specific, thousands of antioxidant supplements had been researched for this purpose, yet many of them showed undesired effects on other body’s tissues. Based on clinical trials, l carnitine can help boost female sex hormones and fertility- whether used alone or with ART (assisted reproductive technology). ALCAR can help manage other conditions as well — including polycystic ovary syndrome (PCOS), endometriosis and amenorrhea.

Technical :L carnitine maintains cellular energy, reduces oxidative stress and minimizes cell death by apoptosis- which are necessary for proper oocyte growth and maturation of blastocyst [17].

6. More Acetyl L Carnitine Benefits: L carnitine/ALCAR for Heart Health

Heart muscle prefers to use fat rather than sugar as a source of energy. The biggest problems arise when the coronary arteries become narrowed and the blood flow and oxygen decrease (there is more need for oxygen to burn fat than sugar for energy). Therefore, carnitine supplements are especially needed for those who have heart problems- for example in cases of heart failure, angina and heart attacks, as it increases the survival rate. It was also found beneficial for managing peripheral arterial disease [18],[19].

L carnitine helps manage high blood pressure, high cholesterol levels, diabetes and sugar imbalances and obesity (see below)- which are all part of the metabolic syndrome.

Technical: mechanism of action: l-Carnitine facilitates transport of long-chain fatty acids into the mitochondrial matrix; cardio protective effects through reduced oxidative stress, inflammation and necrosis of cardiac myocytes [20].

Cardiac autonomic neuropathy (CAN) is common, often unrecognized or treated- and potentially lethal. Is typically described as a complication of diabetes, but is often seen in  MS and other conditions [21]. CAN develops when there is damage to the autonomic nerve fibers that innervate the heart and blood vessels. Symptoms of CAN include rapid heart beats (sinus tachycardia), exercise intolerance, orthostatic hypotension (sudden drop in blood pressure that happens when you stand up from sitting or lying down), abnormal blood pressure regulation, dizziness, presyncope and syncope (faint), cardiovascular diseases and even silent heart attacks.

Carnitine is again, one of the top supplements to consider for treating CAN (along with other supplements that support healthy sugar metabolism). CAN should be treated asap, as is associated with five-fold increased risk of cardiovascular death [22]. CAN can be assessed by looking at heart rate variability (HRV) [23] — whether by using an electrocardiogram in the doctor’s office or an HRV belt (Polar, Wahoo) at home. HRV can be improved with training.

7.More Acetyl L Carnitine Benefits: L carnitine/ALCAR  For Weight Loss, Muscle Growth and Fitness : L carnitine is viewed as one of the most effective supplement to promote endurance and shorten the recovery after workouts as well as burning fat. In peripheral tissues, l carnitine helps transport medium and long chain fatty acids into the mitochondria. This supplement has also strong antioxidant qualities, preventing  DNA damage induced by free radicals [24].

8.More Acetyl L Carnitine Benefits: L Carnitine/ALCAR & Sugar Metabolism: A review/meta analysis of several studies found that l carnitine can improve insulin resistance [25]. Insulin resistance is linked not only with diabetes, but with MS, Parkinson’s, Alzheimer’s disease. All chronic conditions have an underlying unbalanced metabolism of sugar. L carnitine- and even better- ALCAR form can help improve insulin sensitivity, manage diabetes and prevent complications of diabetes such as neuropathy and heart diseases.

ALCAR seems particularly beneficial for treating neuropathic pain (tingling and numbness), according to randomized controlled studies.

Technical: improves nerve fiber regeneration and vibration perception; beneficial effects on nerve conduction slowing, neuropathic pain, axonal degenerative changes and nerve fiber regeneration (in diabetics with neuropathy) [26]. L carnitine increases the expression of PPAR-? and glucose transporters in the liver and muscles (animal models exposed to acute and chronic exercise) [27].

9.L Carnitine/ALCAR Side Effects

ALCAR seems to be a better choice (more effective and possibly safer) compared with l carnitine. Red meats are the best dietary sources of carnitine, however they should be consumed in small amounts. Therefore, supplementing with ALCAR maybe necessary in many individuals to get enough amounts of carnitine. ALCAR supplements are especially important in  those with diabetes, MS and other brain conditions, very active individuals as well as vegans and vegetarians.

Avoid taking high amounts of l carnitine/ALCAR long term- some concerns had been raised based on animal studies (possible increased risk of atherosclerosis from gut microbiome changes) [28],[29]. I suspect other compounds in red meat (rather than l carnitine)- are more responsible for this changes in gut flora. Anyways, would be a good idea to combine L carnitine with a supplement rich in polyphenols like resveratrol [30].  

 Supplementation with l carnitine- is it healthy for thyroid ? L carnitine hypothyroidism link: L-carnitine is a peripheral antagonist of thyroid hormone action (prevents the thyroid hormones getting in the cells in the periphery). Furthermore, l carnitine had been found useful to manage hyperthyroidism [31]. 

From this perspective, l carnitine looks beneficial for those with hypothyroidism and detrimental for those with hypothyroidism. However, l carnitine seems helpful for individuals with hypothyroidism, too- especially for treating fatigue in those under age 50, who developed hypothyroidism after thyroid cancer surgery [32].

What I think regarding L carnitine/ALCAR side effects : Carnitine is helpful to anyone who has a carnitine deficiency. It looks that carnitine deficiency is higher in those with hyperthyroidism, where a milder shortage of this amino acid is seen in hypothyroidism [33].

Since 95% of carnitine is found in skeletal muscles, muscle weakness is a key symptom of carnitine deficiency. The more active you are, the more benefits you will get from carnitine supplements. Adding l tyrosine (to support healthy thyroid levels of hormones) to l carnitine would be a great combination for those with hypothyroidism. 

Overall, carnitine shows no toxicity, no contraindications or interactions with drugs and no teratogenicity (however, should be taken with caution during pregnancy or if you take blood thinning drugs) [34].

10.Other Ways To Increase Boost l Carnitine/ALCAR levels: Diet and Exercise

Good sources of carnitine: meat (especially red meat, but also fish and poultry), dairy. Obviously, vegans and vegetarians and those who do not absorb properly this nutrient will need higher doses of l carnitine/ALCAR supplements.

Levels of ALCAR in the blood are increased during fasting, exercise (especially high intensity exercise [35], while the muscle levels of carnitine decrease [36]. ALCAR would be a great supplement for active individuals who exercise regularly.