Acetyl-L-Carnitine (ALCAR, ALC or LAC) is a synthesized version of L-Carnitine. Which is a derivative of the amino acids lysine and methionine.
ALCAR is more bioavailable than L-Carnitine. It easily crosses the blood-brain barrier. And delivers L-Carnitine across cell membranes (which it would not be able to cross on its own).
L-Carnitine is naturally made in your liver and kidneys. And then transported to other tissues including your brain and heart.
ALCAR helps:
- Brain Energy Metabolism. ALCAR helps transport of fatty acids into mitochondria where they’re needed for energy metabolism. Fueling your cells “power plants” can boost physical and mental energy.
- Neurotransmitters. ALCAR is a necessary ingredient for acetylcholine formation. Which boosts memory, mental alertness, and fluid thought.
- Brain Optimization. The antioxidant properties of Acetyl-L-Carnitine provides neuroprotective qualities, boosts Brain-Derived Neurotrophic Factor (BDNF), and promotes cerebral blood circulation.
Table of Contents
Overview
L-Carnitine is an amino acid that’s synthesized in your body. You also get it from red meat and dairy.
L-Carnitine is considered a “conditionally essential” nutrient because when your body uses it faster than it can produce it, you need supplemental L-Carnitine either from food or a supplement.
L-Carnitine is used throughout your body. Here we’re talking about the Acetyl-L-Carnitine form of L-Carnitine because of its affects on brain health and chemistry.
L-Carnitine vs. Acetyl-L-Carnitine: What’s the Difference?
L-Carnitine and Acetyl-L-Carnitine are often referred to as Carnitine. But each are structurally different, and each has its advantages.
L-Carnitine: Provides energy for the mitochondria of your cells, but is not capable of crossing the blood-brain barrier. Supplemental L-Carnitine is difficult for your body to absorb; only 18% of it reaches your bloodstream.
L-Carnitine is favored by athletes and dieters who want Carnitine’s fat-metabolizing benefits. But are not seeking any brain benefits.
Acetyl-L-Carnitine: Is easier to absorb and used by your body than L-Carnitine. One study showed using 2 grams daily for 50 days boosted blood ALCAR levels by 43%.[i]
ALCAR does everything that L-Carnitine does, but can also cross the blood-brain barrier. In another study, researchers found that ALCAR protects brain cells from oxidative stress, while L-Carnitine does not.[ii]
How does Acetyl-L-Carnitine Work in the Brain?
Acetyl-L-Carnitine boosts brain health and function in several ways. But two in particular stand out.
- ALCAR boosts acetylcholine, a neurotransmitter tied to memory and overall brain function.Acetyl-L-Carnitine is a precursor to acetylcholine in the presence of Coenzyme-A. ALCAR donates a “methyl group” to make acetylcholine.[iii]
Alzheimer’s-diseased brains show a 25% to 40% reduction in carnitine acetyltransferase, a brain enzyme that works with L-Carnitine & Acetyl-L-Carnitine.
This brain enzyme decline led researchers to link low ALCAR with low acetylcholine, and Alzheimer’s onset. They went on to suggest ALCAR as a viable therapy for brain regeneration.[iv]
- ALCAR promotes brain energy by fueling your brain cell’s mitochondria.[v]
ALCAR works as a shuttle transport for fatty acids through cell membranes. Right to the cell powerplant mitochondria.[vi]
- As ALCAR shuttles fatty acids into mitochondria, it provides the fuel that is burned for energy.
- As ALCAR shuttles fatty acids out of mitochondria, it flushes out toxic byproducts.
ALCAR maintains mitochondria in nearly every cell of your body. Your brain consumes at least 20% of your body’s energy. And generates a lot of toxic byproducts. So ALCAR is particularly important for a healthy brain.
How things go bad:
As we get older, our brain chemistry and energy metabolism changes.[vii]
↓ Nerve growth factor in the brain declines
↓ Acetyl-L-Carnitine levels decline
↓ Acetylcholine levels decline
↓ Mitochondria loses efficiency
All of these age-related changes are contributing factors to the neurodegenerative diseases of aging, including Alzheimer’s and dementia.
ALCAR to the rescue.
Research from the Linus Pauling Institute at Oregon State University shows that Acetyl-L-Carnitine will:[viii]
- Restore efficient mitochondrial energy production
- Replenish age-related changes to mitochondrial structure
- Replenish ALCAR and acetylcholine levels in the brain and body
ALCAR’s has the ability to boost acetylcholine and rejuvenate brain cells (including mitochondria). This has been proven to benefit those with age-related brain diseases like Alzheimer’s and major depression.[ix]
How does Acetyl-L-Carnitine feel?
You may not feel ALCAR… unless you’re elderly or have Erectile Dysfunction. Within those specific groups, Acetyl-L-Carnitine helps with memory, mood, mental performance and the ability to get and maintain an erection.
ALCAR’s brain support and its ability to fuel the mitochondria in your brain cells should boost cognition in all age and gender groups.
As a nootropic, ALCAR user reviews report a boost in energy and quick thinking.
The Research
In one study, researchers showed that ALCAR may have positive effects for depression and dementia.[x]
Another study out of Italy; researchers showed that Acetyl-L-Carnitine stimulated the growth of new neurites. More of these minute projections from nerve cell bodies meant increased signaling between cells throughout the central nervous system (brain and spinal cord).[xi]
And a study conducted at the Mount Sinai School of Medicine in New York found that ALCAR has potential in treating the symptoms of Parkinson’s Disease. By directly affecting mitochondrial respiration and assisting dopamine neurons and the use of dopamine in the brain.
ALCAR helps with Mild Cognitive Impairment (MCI)
A gold-standard double-blind, randomized controlled trial on 1,204 people showed significant effect on attention, mental performance, memory and higher mental functions.[xii]
In this study ALCAR seemed to ward off further brain deterioration. And could be considered as therapy for brain degeneration.
Acetyl-L-Carnitine slows rate of cognitive decline
130 Alzheimer’s patients were given ALCAR or a placebo daily for a year. They were tested across 14 points of cognitive performance.
This research showed a slower decline in cognitive performance with the ALCAR group compared to the placebo group.[xiii]
ALCAR effective for Chronic Fatigue Syndrome
Acetyl-L-Carnitine has been shown to improve fatigue in patients with chronic fatigue syndrome.
In a randomized, double-blind, crossover study; 36 people were treated for 3 months with either amantadine (used to treat Chronic Fatigue), or 1 gram of ALCAR twice daily.
The results of the study showed that ALCAR was better tolerated and more effective than the pharmaceutical for fatigue.[xiv]
Acetyl-L-Carnitine protects from oxidative damage of Ecstasy (MDMA)
Research has shown ALCAR to be effective in protecting your mitochondria from oxidative stress. But these guys took it a step further.
Male rats were given Acetyl-L-Carnitine before a dose of Ecstasy (MDMA). ALCAR pretreatment “exerts effective neuroprotection against MDMA-induced neurotoxicity at the mitochondrial level”, said the researchers.[xv]
Keep that in mind before your next party.
ALCAR for Erectile Dysfunction?
In this study, 120 patients were split into 3 groups. Group 1 was given 160 mg of testosterone per day. The 2nd group was given 2 grams of Propionyl-L-Carnitine plus 2 grams of Acetyl-L-Carnitine per day. And the 3rd group a placebo.
Did you know that there’s an International Index of Erectile Function?
Turns out the Propionyl-L-Carnitine/Acetyl-L-Carnitine stack was better than testosterone for erectile dysfunction. Without the side effects of an enlarged prostate, better orgasms, more sexual desire and improved mood.[xvi]
Dosage Notes
- Acetyl-L-Carnitine suggested dosage for cognitive benefits is 1 – 4 grams per day.
- For improved mood and elimination of chronic fatigue, 1 – 3 grams of ALCAR per day.
- For age-related memory concerns, 1 – 2 grams of ALCAR per day.
ALCAR is water-soluble and can be taken on an empty stomach with water. A few supplement manufacturers recommend taking their Acetyl-L-Carnitine with a meal. Which implies that it’s fat-soluble for which I’ve found no evidence in the scientific literature.
Side Effects
Acetyl-L-Carnitine is produced naturally in your body. So is considered well-tolerated and safe.
Side effects are rare but can include nausea, vomiting, increased agitation, weight loss, and restlessness.
You can also see an increase in seizure frequency if you have any kind of seizure disorder.
Available Forms
- Acetyl-L-Carnitine: L-Carnitine with an extra acetyl group. This version is more bioavailable and easily crosses the blood-brain barrier.
- L-Carnitine: This is the standard form of carnitine found in food.
- Lipo-Carn®: A proprietary blend of Alpha-Lipoic Acid and Acetyl-L-Carnitine. Studies show this combination is a powerful anti-aging duo.
Together, these two help combat diabetes, boost energy production, maintain proper cognitive function, protects the body from radiation and chemical toxins and helps immunity.[xvii] - Propionyl-L-Carnitine: L-Carnitine combined with propionic acid. This form is noted for its antioxidant activity, and is used for heart health applications. Also useful for erectile dysfunction.
ALCAR 750 mg is also included in the Performance Lab Energy nootropic stack.
Nootropics Expert Recommendation
Acetyl-L-Carnitine 500 – 1,500 mg per day
We recommend using Acetyl-L-Carnitine as a nootropic supplement.
Your body does synthesize some ALCAR on its own. And from the food you eat. But most Acetyl-L-Carnitine comes from red meat. And unless you eat a lot of great quality grass-fed beef or mutton…
ALCAR is especially helpful for those suffering from age-related cognitive decline. Studies show it helps stop or reverse brain degeneration with Alzheimer’s Disease, and depressive disorders. Particularly in the early stages of the disease.
We suggest starting with a dose of 500 mg daily. ALCAR is a great compliment to a stack including Piracetam. Add a choline source (Alpha GPC or CDP-Choline) at a ratio of 1:4. 1 gram of Alpha GPC to 4 grams of Piracetam. Take enough choline to eliminate a racetam-induced headache. Then add 500 mg of ALCAR.
Some have found ALCAR stacked with Coenzyme Q-10 has a profound effect on everything from mood to bipolar disorder. Especially combined with Alpha-Lipoic Acid.
Age-related cognitive disorders like Alzheimer’s may want to up the dose to 1,500 mg per day.
[i] Rebouche C.J. “Kinetics, pharmacokinetics, and regulation of L-carnitine and acetyl-L-carnitine metabolism.” Annals of the New York Academy of Sciences 2004 Nov;1033:30-41. (source)
[ii] Liu J., Head E., Kuratsune H., Cotman C.W., Ames B.N. “Comparison of the effects of L-carnitine and acetyl-L-carnitine on carnitine levels, ambulatory activity, and oxidative stress biomarkers in the brain of old rats.” Annals of the New York Academy of Sciences2004 Nov;1033:117-31. (source)
[iii] White H.L., Scates P.W. “Acetyl-L-carnitine as a precursor of acetylcholine.” Neurochemical Research 1990 Jun;15(6):597-601. (source)
[iv] Kalaria R.N., Harik S.I. “Carnitine acetyltransferase activity in the human brain and its microvessels is decreased in Alzheimer’s disease.”Annals of Neurology 1992 Oct;32(4):583-6. (source)
[v] Berg J.M., Tymoczko J.L., Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. (source)
[vi] Berg J.M., Tymoczko J.L., Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. (source)
[vii] Costell M., O’Connor J.E., Grisolía S. “Age-dependent decrease of carnitine content in muscle of mice and humans.” Biochemical and Biophysical Research Communications 1989 Jun 30;161(3):1135-43. (source)
[viii] Gomez L.A., Heath S.D., Hagen T.M. “Acetyl-L-carnitine supplementation reverses the age-related decline in carnitine palmitoyltransferase 1 (CPT1) activity in interfibrillar mitochondria without changing the L-carnitine content in the rat heart” Mechanics of Aging Development 2012 Feb-Mar; 133(0): 99–106. (source)
[ix] Pettegrew J.W., Levine J., McClure R.J. “Acetyl-L-carnitine physical-chemical, metabolic, and therapeutic properties: relevance for its mode of action in Alzheimer’s disease and geriatric depression.” Molecular Psychiatry 2000 Nov;5(6):616-32. (source)
[x] Ferrari F., Gorini A., Villa R.F. “Functional proteomics of synaptic plasma membrane ATP-ases of rat hippocampus: effect of l-acetylcarnitine and relationships with Dementia and Depression pathophysiology.” European Journal of Pharmacology 2015 Jun 5;756:67-74. (source)
[xi] Taglialatela G., Navarra D., Olivi A., Ramacci M.T., Werrbach-Perez K., Perez-Polo J.R., Angelucci L. “Neurite outgrowth in PC12 cells stimulated by acetyl-L-carnitine arginine amide.” Neurochemical Research 1995 Jan;20(1):1-9. (source)
[xii] Montgomery S.A., Thal L.J., Amrein R. “Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer’s disease” International Clinical Psychopharmacology 2003 Mar;18(2):61-71. (source)
[xiii] Spagnoli A. et. Al. “Long-term acetyl-L-carnitine treatment in Alzheimer’s disease.” Neurology. 1991 Nov;41(11):1726-32. (source)
[xiv] Tomassini V., Pozzilli C., Onesti E., Pasqualetti P., Marinelli F., Pisani A., Fieschi C. “Comparison of the effects of acetyl L-carnitine and amantadine for the treatment of fatigue in multiple sclerosis: results of a pilot, randomized, double-blind, crossover trial.” Journal of Neurological Science 2004 Mar 15;218(1-2):103-8. (source)
[xv] Alves E. et. Al “Acetyl-l-carnitine provides effective in vivo neuroprotection over 3,4-methylenedioximethamphetamine-induced mitochondrial neurotoxicity in the adolescent rat brain” Cellular Neuroscience Volume 158, Issue 2, 23 January 2009, Pages 514–523 (source)
[xvi] Cavallini G., Caracciolo S., Vitali G., Modenini F., Biagiotti G. “Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging.”Urology 2004 Apr;63(4):641-6. (source)
[xvii] Liu J., Head E., Gharib A.M., Yuan W., Ingersoll R.T., Hagen T.M., Cotman C.W., Ames B.N. “Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: partial reversal by feeding acetyl-L-carnitine and/or R-alpha -lipoic acid.” Proceeding of the National Academy of Sciences of the United States of America 2002 Feb 19;99(4):2356-61. (source)
Ok, thanks David.
Hi David! I read on Reddit a comment from a man who was thinking his ALCAR was responsible for the increased hair shedding. Have you ever heard of that? I have problem with hair shedding, that is why I ask. Thank you
Lana, on the contrary ALCAR or L-Carnitine has been shown to promote hair health and growth. Do a search for “Acetyl L-Carnitine and hair loss” and you’ll see what I mean.
Hi David,
I would like to ask you about third dose of ALCAR. Is it better to take it in the evening or before bed?
Is it possible it can keep me awake? And also I would like to ask you about CBD oil and ALCAR.
CBD oil always worked well for me, but the last time I took it I didn’t like the effect. I experienced something like a brain fog. The only nootropic that I added to my stack recently is ALCAR.
Do you think maybe ALCAR and CBD Oil don’t go together for me?
Thanks.
Mick, ALCAR is funny that way because it can have a different effect on each person. I used to use a 3rd dose of ALCAR in my late afternoon stack. But found lately that is was having a bad effect on sleep. So stopped using my late 3rd ALCAR dose.
It’s not that CBD Oil and ALCAR don’t go together. It is whether they work for you. Only you can decide that.