Our body makes a host of nutrients and molecules and sometimes a higher dose is more useful for optimizing our body and mind. L-carnitine is one of the compounds we produce ourselves, but further supplementation can yield mitochondrial anti-aging support in addition to alertness and neuroprotection.

L-carnitine and the related Acetyl-L-Carnitine (ALCAR) are both useful in protecting the brain and body. L-carnitine has a strong antioxidant profile that can help protect the brain from free radicals [1]. Supplementation also increases focus and attention in some patients [2] and can reduce mental and physical fatigue as well [3].

This supplement is a great resource for young healthy adults and elderly alike. It is a great source of cognitive protection in the elderly, which include things like learning ability and memory retention [4]. It also happens to support children with symptoms of ADHD [5]. Compared to many nootropics, L-carnitine is well studied and well-tolerated and thus is good for beginners.

Also Known As

Acetyl-L-Carnitine, ALCAR, Acetylcarnitine, L-Carnitine, L-Carnitine-L-Tartrate, LCLT, Glycine Propionyl-L-Carnitine, GPLC, Levocarnitine, Levacecarnine, L-3-hydroxytrimethylamminobutanoate

Editors’ Thoughts on L-Carnitine

Acetyl-L-carnitine (ALCAR) is quite a powerful compound. I did feel stimulation by using it in addition to the CILTeP stack and I had a theory about why that is. According to literature, ALCAR can help with fatty acid metabolism (i.e: burning fat). When I took the supplement my brain felt like it shifted into fat utilization for energy and it was noticeable.

I was hungry a lot slower because my brain was being fed plenty of fat. This is just my hypothesis. I felt great using the supplement and it seemed like it was quite stimulating as well.

Mansal Denton, Nootropedia Editor

Benefits of L-Carnitine

Humans create L-carnitine and eat animal products with this amino acid, but further supplementation can have even more benefits. For children ages 6-13 who are diagnosed with ADHD, carnitine can have a profound impact on symptoms. One study suggests a 20 – 65% reduction in symptoms [6]. Given the epidemic of children taking prescription drugs with amphetamines, it is useful to find an amino acid (and a naturally occurring one at that) that can have a similar effect as medications.

This amino acid is also useful in the metabolism and protection of cellular mitochondria, which is a powerful anti-aging and neuroprotective agent. Many of the anti-oxidant enzymes prevent mitochondrial damage, which can help to protect the brain from neuronal loss (especially from toxins like alcohol) [7].

Working long hours is becoming more and more common in the western and developing world. The rate of globalization is making competition more difficult to overcome and being able to work for longer while maintaining the quality is a big advantage. Some people use ALCAR and L-carnitine in order to prevent mental fatigue. One study showed ALCAR could not only reduce mental (and physical) fatigue, but it could also improve cognition via a MMSE test [8].

One of the major benefits of L-carnitine is the increase in general cognition. One study showed that participants taking L-carnitine improved their cognition for the time the drug was in their system, but many of them returned to baseline after the drug was no longer in their system [9]. To think that the drug’s effects can be so acute is useful for supplementation before an exam, big project, or presentation.

Due to L-carnitine’s synthesis in the body, it is useful for a host of physical benefits as well. Many of the L-carnitine benefits are for blood pressure, heart rate, or blood flow as well. Taking this is thus a whole-body enhancement as opposed to purely mental and cognitive.

Acetyl-L-Carnitine Benefits

Most of the benefits of acetyl-L-carnitine are similar with L-carnitine, but with a few bonuses. First of all, most of the studies use ALCAR as their source of carnitine for test purposes. Either it is more beneficial or it has more bioavailability.

A major benefit of ALCAR is the cholinergic modulation. ALCAR is a great way to increase the synthesis of acetylcholine [10], which is a neurotransmitter that is responsible for memory formation and retention. Beyond acetylcholine, ALCAR can also increase serotonin in the hippocampus region of the brain by 22% [11].

Given these slight variations, many people opt to use ALCAR as their source of carnitine supplements.

Side Effects of Carnitine

Even though carnitine is an amino acid that human bodies create, overdoing anything (no matter how healthy) can always be a bad thing. There are a few side effects of carnitine to consider, but most of them are rare and mild. The primary concern is gastrointestinal problems, which are usually just related to the symptom acclimating to the supplement. A few of the studies related to toxicity and safety have determined that men taking L-carnitine tartrate in a dose of 3 grams (3 times more than recommended) found no safety concerns [12].

Some of the studies showed that carnitine would interact with other nutrients. In one example, carnitine was combined with caffeine and the two improved physical endurance than either of the two alone. The study suggested that there was a synergistic effect between caffeine and ALCAR [13].

Another positive side effect of carnitine is the combination with alcohol. Despite alcohol’s neurotoxins on the brain, taking acetyl-L-carnitine can help protect the brain against neurodegeneration [14].

Carnitine Dosage

Getting carnitine in the form of food is more easily absorbed than supplements. Food is absorbed in the intestines between 57 – 84% while supplements are only 14 – 18% [15].

The carnitine dosage is a standard 500 – 2000 mg daily and a good starting point is around 1000 mg per day. However, there are different types of supplements with different dosages (ALCAR requires much less usually) so make sure you know the difference and keep this in mind.

How and Where to Buy Carnitine

As mentioned, you’ll need to know which carnitine supplement you desire and for what purpose in order to get the right product. L-carnitine tartrate is one type of supplement, which is usually used for physical endurance and has a higher dose range.

If you are looking for blood flow problems, there is a GPLC source, but most people are after cognitive enhancement through acetyl-L-carnitine. The best way to tell the difference between the three is to simply purchase carnitine online.

There are plenty of products in your local grocery or health food store, but it is better to buy ALCAR online so that you can get the best prices and a much better / more informed experience.

When you buy ALCAR powder or capsules, make sure that you have experience putting it together or eating the powder by itself. If the taste doesn’t appeal to you, go for ALCAR capsules instead.

Nootropedia puts our trust in this ALCAR product by Pure Nootropics, who are trusted suppliers in the nootropics community.

Selected Community Experiences

I had a noticeable increase in energy and (interestingly enough) my libido as well.” [16] – pidginduck

I take it first thing in the morning, then make a trip to the bathroom. When I pee it smells like burned plastic.” [17] – kabuto

References (Click to Expand)
  1. //www.ncbi.nlm.nih.gov/pubmed/21701126
  2. //www.ncbi.nlm.nih.gov/pubmed/15039515
  3. //www.ncbi.nlm.nih.gov/pubmed/17658628
  4. //www.ncbi.nlm.nih.gov/pubmed/17658628
  5. //www.ncbi.nlm.nih.gov/pubmed/18286595
  6. //www.ncbi.nlm.nih.gov/pubmed/12213433
  7. //www.ncbi.nlm.nih.gov/pubmed/20708681
  8. //www.ncbi.nlm.nih.gov/pubmed/17658628
  9. //www.ncbi.nlm.nih.gov/pubmed/20098226
  10. //www.ncbi.nlm.nih.gov/pubmed/6790669
  11. //www.ncbi.nlm.nih.gov/pubmed/22549035
  12. //www.ncbi.nlm.nih.gov/pubmed/11726261
  13. //www.ncbi.nlm.nih.gov/pubmed/11922111
  14. //www.ncbi.nlm.nih.gov/pubmed/20708681
  15. //www.ncbi.nlm.nih.gov/pubmed/15591001
  16. //www.reddit.com/r/Nootropics/comments/1nw8mk/alcar_side_effects_after_10_months_of_continuous/
  17. //www.reddit.com/r/Nootropics/comments/mgs19/alcar_makes_my_urine_smell_weird/
Other Scientific Resources (Click to Expand)
  1. //www.ncbi.nlm.nih.gov/pubmed/20533327
  2. //www.ncbi.nlm.nih.gov/pubmed/18607224
  3. //www.ncbi.nlm.nih.gov/pubmed/15591001
  4. //www.ncbi.nlm.nih.gov/pubmed/2756917
  5. //www.ncbi.nlm.nih.gov/pubmed/20398344
  6. //www.ncbi.nlm.nih.gov/pubmed/12908852
  7. //www.ncbi.nlm.nih.gov/pubmed/6219439
  8. //www.ncbi.nlm.nih.gov/pubmed/6361812
  9. //www.ncbi.nlm.nih.gov/pubmed/20306513
  10. //www.ncbi.nlm.nih.gov/pubmed/1962562
  11. //www.ncbi.nlm.nih.gov/pubmed/6692007
  12. //jn.nutrition.org/content/119/12/1907.full.pdf
  13. //www.ncbi.nlm.nih.gov/pubmed/19931062
  14. //www.ncbi.nlm.nih.gov/pubmed/972150
  15. //www.ncbi.nlm.nih.gov/pubmed/17048190
  16. //www.ncbi.nlm.nih.gov/pubmed/1376181
  17. //www.ajcn.org/content/50/2/301.full.pdf
  18. //www.ncbi.nlm.nih.gov/pubmed/11043928
  19. //www.fasebj.org/content/6/15/3379.short
  20. //www.ncbi.nlm.nih.gov/pubmed/21827492
  21. //www.ncbi.nlm.nih.gov/pubmed/19491916
  22. //www.ncbi.nlm.nih.gov/pubmed/20416111
  23. //www.ingentaconnect.com/content/adis/cdi/1999/00000017/00000004/art00008
  24. //www.ncbi.nlm.nih.gov/pubmed/18065594
  25. //www.ncbi.nlm.nih.gov/pubmed/12875611
  26. //www.biomedcentral.com/content/pdf/1743-7075-7-30.pdf
  27. //www.ncbi.nlm.nih.gov/pubmed/20098226
  28. //www.ncbi.nlm.nih.gov/pubmed/22395524
  29. //www.ncbi.nlm.nih.gov/pubmed/18337137
  30. //www.ncbi.nlm.nih.gov/pubmed/22420015


Nootropedia is meant to be a resource for individuals researching drugs and supplements that are good for brain health, otherwise known as nootropics, and thus we are the Nootropics Encyclopedia. Because of our in-depth coverage of this topic, our community has requested that we cover other brain health topics and "lifehacks" so that has become the focus of Nootropedia.