L-Carnitine Health Benefits

| Modified on Sep 16, 2023

Lauded as a super-supplement, l-carnitine has such applications as amping up the fat burning process, fighting fatigue and relieving depression. However, that is not all the supplement can do. Taken as a regular supplement or even a periodic treatment, l-carnitine is effective for supporting general health and treating a variety of specific conditions.

What is L-Carnitine?

A naturally occurring amino acid, l-carnitine is a nutrient found in red meat as well as other natural sources. The nutrient is also produced naturally in the body. The nutrient is synthesized in specific areas of the body including the liver, kidneys and brain. Once produced, the body actively transports the nutrient to other areas of the body for use.

The nutrient functions in at least two fundamental ways in the body. L-carnitine aids in the transport of fatty acids in the body, which supports metabolic processing and neural development. The supplement also plays a role in supporting energy regulation with its direct ties to metabolic functioning.

Health Benefits of L-Carnitine

As it aids in the performance of such crucial processes, an adequate amount of the nutrient is vital. Most research suggests that individuals are able to naturally produce enough l-carnitine; however, some individuals do not produce enough of the supplement due to a genetic disorder, certain medication, or dietary choices.

The nutrient is often used as a supplement. The supplement is effective for individuals with genetic disorders, who are taking certain medication, or are undergoing certain medical procedures including hemodialysis. It is also an important supplement for vegetarians, restrictive dieters, and low-weight or premature infants.

L-carnitine is also used as a supplement for treating a host of conditions. The supplement can be used for conditions associated with the heart and cardiovascular system including chest pain, congestive heart failure, diphtheria, heart attack, circulation problems, and high cholesterol. The supplement also aids in treating certain muscle conditions, male infertility, Rhett syndrome, anorexia, chronic fatigue syndrome, diabetes, overactive thyroid, attention deficit-hyperactivity disorder, leg ulcers, and Lyme disease. Many individuals use the nutrient as a supplement to support athletic performance and endurance as well.

As L-carnitine helps the body produce energy and carry out important metabolic processes, it is an important nutrient in any diet. It can also be used to treat a range of developed health conditions.


2 User Reviews
5 star (2) 

Posted by Tess (Palm Beach, FL) on 11/10/2008

Dreaming Remedy:

I started taking L-Carnitine (among other supplements) recently and around the same time started to recollect my dreams, about 3-4 a night instead of 1 every once in a while. I didn't make the connection until I stopped the L-Carn last week and almost immediately stopped being able to recall any dreams. I started up again last night and was able to remember 3 dreams this morning. I take 1 TBL on an empty stomach 3x a day.

Replied by Rick
(Chicago, Il)

I can't understand why everybody WANTS to recall their dreams! I know dreaming is necessary for health, but I generally find my dreams dumb, annoying, or disturbing. I'd LIKE to forget them, and wonder if anyone has any ideas on how to *discourage* dream recall and overly-vivid dreaming. Thanks.

Replied by Shawn
(Chicopee, Ma)

funny reply rick! I too think my dreams are dumb annoying or disturbing.

Replied by Test
(Toronto, Canada)

THC will interrupt your dream recall.

Replied by Matt
(Millbrook, Ny)

Both L-Carnitine and Acetyl-L-Carnitine definitely improve my ability to have vivid dreams, as well as to recall them. It works even if I take say 500 mg up to 15 hours before falling sleep. Not only that, but now when I wake up, I can go back to sleep and choose to continue the same dream I had woken up from, with the option of more consciously deciding what I'll do in the dream while I'm awake! I find it pretty incredible. I remember reading somewhere years ago that when you wake up and then fall back asleep, you're 48 times more likely to have a lucid dream........ Anyway, a definite YEA for Carnitine and Dreaming.

Replied by Cora

First time user here and I have noticed I have been getting bad dreams, also. I am not feeling as fatigued which is another benefit it has for someone who rarely eats red meat. Anyway, I would rather choose to not recall my dreams myself and had found that HOPS lessens vivid-dreaming. Correct me if I am wrong, but drinking a little beer at night worked. It wasn't long after that it felt like a task. There are some sleep/mood support supplements that will have hops. Avoid Valerian esp. if you don't want to remember your dreams.

Fatigue, Low Energy

2 User Reviews
5 star (2) 

Posted by Jane (Texas, U.S.A) on 09/21/2008

I just wanted to let you know that I after suffering from serious adrenal burnout and chronic fatigue and now found more energy by taking L-carnitine. I couldn't even get off the couch before and now I have 80% percent more energy. I also eventually added in q10 and that together with magnesium put me back to being the energizer bunny. I have read several times that people with CFS also have depleted L-carnitine. Hope this can help someone suffering from this horrible fatigue.

Replied by Tina
(Dartmouth, NH)

Dear Jane, wow! Thank you so much for suggesting L Carnitine. I immediately ordered some liquid, pharmaceutical grade after reading your post. (Is liquid better than powder?) You are absolutely right, it is the energizer bunny remedy, holy moly! I usually get super fatigued in the afternoon, but a tablespoon of L-C on an empty stomach 3x a day has stopped my desperate desire to take a long nap. Are there any side effects to taking this for long term? I have noticed (sorry to sound gross) that it turns my stools orange though! I don't eat red meat, so this amino might be fixing that...

Replied by Shawn
(Los Angeles, CA)

To Tina: Be careful you are not depleting your iron. Light colored stools are an indication of low iron.. A good way to bring that up is, a table spoon of molassas, or Colostrum.


1 User Review
4 star (1) 

Posted by Wendy (Plover, WI U.S.A) on 10/29/2007

Celiac causes many health issues. Diabetes, fibromyalgia,blemishes, yeast, MS,attention deficient, lupus, cancer, eczema, psoriasis,low thyroid,arthritis,acid reflux and many more. Good Book- Dangerous Grains by Braly Diet- eating no dairy or grains, Vit B12 methycobalamin shot, Vit D3, HCl and enzymes with meals, dairy free acidophlus when stomach acid is low helps. I also did LDN. I don't like drugs but LDN helps since there is so much hidden dairy and gluten it is hard to avoid it. I take 41 vitamins since my intestines are not absorbing as much as they should right now.People do not see my MS. I take things to counteract it like coenzyme Q10, rhodiola,biotin, carnitine, acetyl carnitine which helps the mitochondria work better which also helps fibromyalagia people too. I take the good oils:fish oil, evening primrose oil, Krill oil,lecithin, phoshpadityl serine/DMAE.

General Feedback

1 User Review
5 star (1) 

Posted by Len ( Las Vegas, NV) on 07/10/2009

Can someone tell me the difference between L-carnitine and acetyl-l-carnitine? I see there's a big difference in price. When clicking on L-carnitine under the supplements section here (on EC) I see people are talking about both as if they are one in the same and I know there not. Thanks-Len

Replied by Luis
(Cali, Colombia)

Dear Len:

Briefly, L-Carnitine is for heart, Acethyl-L-Carnitine is for brain.

To your best days.


(Miramar Florida)
23 posts

Hi, my question is, seeing acetyl l-carnitine, works for the brain and L-carnitine for the heart. If I need help in both areas. Should I take both AL-Carn & L-Carn.? Thank you in advance.

Replied by Becky
(La Porte, Texas)

I do not understand why L-Carnitine is recommended by some you, to take on an empty stomach. I have tried that, and it makes me very nauseated. So I am definitely eating something first. What are the benefits of taking on empty stomach?

Replied by Lindseynarrates
(Atlanta, Georgia, Usa)

It is because of two reasons: Firstly, as with basically ALL free-form amino-acids, you are taking it for a specific reason, and need it more than the other amino-acids, and if you eat something that contains a large amount of OTHER amino-acids, it will absolutely compete for absorption. Secondly, as with basically all vitamin, mineral, herb, and amino-acid supplements, absorption is significantly enhanced when taken WITHOUT food, with several exceptions of course, but we are talking about acetyl l-carnitine.

HOWEVER...and this is VERY important: It is very advisable to eat SOMETHING that contains a decent amount of carbohydrates, especially glucose, because acetyl l-carnitine, especially when coupled with ALA--alpha lipoic acid--drastically and rapidly lower blood-sugar, and I actually had a very severe hypoglycemic-attack about six days ago because I took a "rather" large dose of ALA and acetyl l-carnitine on a fully empty stomach, and had not eaten for about 10 hours, or so.


Mental Clarity

1 User Review
5 star (1) 

Posted by Molly (Madison, USA) on 04/11/2008

"One time I purchased a bottle of 5-htp, and after taking one capsule morning & evening, just twice, I threw the bottle away. My reaction to 5-htp was horrific; upon further research I learned that high levels of serotonin are associated with SEVERE ANXIETY. I also read that the spice ginger is a serotonin antagonist, so I have a bottle on hand, just in case I ever feel so anxious ever again.

Then I read somewhere online that there is a set of people whose depression responds to Acetyl L-Carnitine, they said the depression lifted in these people when using 3-4 grams a day, and to take two grams of acetylcarnitine on an empty stomach, first thing in the morning.

This amino acid is the most amazing substance; I've never been able to take more than 2 grams per day - there is such great mental clarity, there is utter inability to be depressed, but there simultaneously is no euphoria - just calm lucid clarity. I've read that it assists the brain in making many different neurotransmitters - so it is not anything, not anything at all like 5-htp which floods the brain with serotonin - which, if you don't need it, might create severe anxiety.

Replied by Robin
(Minneapolis, MN)

I tried 5htp a few times too, and I didn't feel too hot on it. Same for KavaKava and St.Johnswort. So for those having this same problem, you may want to try acetyl-l-carnitine instead. But it's not really for energy. But L-carnitine is great for the heart. It helps take the pressure off my chest. Won't entire keep things at bay (not a cureall) but helps tremendously. I can do a little more with my muscles too. The heart is a muscle. This is not a 'one thing' fixit. If you need l-carnitine, odds are you need a slew of other things too to get balanced. Deficiences this large don't happen all by their lonesome. Carnitine is also present in beef.

I have adrenal burnout, chronic fatigue, heart attack and obesity. Swelling due to tired organs doesn't help any either. Currently I am (thanks to this site!) planning to take some iodine products (along with necessary co-nutrients to avoid heart palpitations). Maybe then the swelling/circulation can be helped more. But really folks, l-carnitine has enabled me to go to work when maybe I should've been in the hospital. And I firmly believe there were days it just helped me to be alive the next morning. I take two 500mg capsules every night now. Also take vit. C (like at least 1gram/day). That is why dogs don't have arteriosclerosis -- their bodies make vit. C and ours does not. A good one is the powder in the packets that fizz in water(and not from the drugstore). Better than the sports drinks for you as it has other goodies too. Now. L-carnitine works. There is some made from N-Carnitine (not a good idea) and some that is L-carnitine from the start. Get the good one. And I have no idea how to tell them apart. That is the reason for difference in price. You ALWAYS pay for quality when it comes to supplements; but also for low quality too for brand names. So do some thinking instead of blindly trusting, ok? Take it always on empty stomach; it won't interfere with anything that I know of (I am not a dr.) because it is a protein that is in meat, but where they make it from I don't know. Acetyl-l-carnitine and l-carnitine are both good for your heart. I kept my ex-husb from dying taking a-l-c alone, so that aught to tell you how good they work. He took them when he was having a heart spell and he always said it made him feel better. Now that I am having the same problem, yep, it helps me too. BUT I found out also about l-carnitine, which is more specifically a heart helper (because the heart is a muscle).

Replied by Jill
(Avenel, New Jersey)

So which one is better to help with fatigue? L-Carnitine or Acethyl-L-Carnitine? I'm confused! Thanks!

Replied by Robin
(Minneapolis, Minnesota)

L-carnitine is for muscles, period. In my opinion, acetyl-L-carnitine helps with the heart somehow a little, but is mainly for the brain. "Car... " always pertains to stuff connected to heart from what I can tell. Anything that helps the heart, helps your whole self cause you feel better when your heart is doing ok. But if you don't have heart problems, just go with L-carnitine; and if you do have heart problems, try the other sometime and see. Remember, empty stomach.

Replied by Goldtopsam
(Arlington, Texas)

Acetyl L-Carnitine(ALCAR) is an acetylated form of L-Carnitine. It terms of of bioavailability it is superior to L-Carnitine, however a portion of L-carnitine is converted to ALCAR after ingestion. Glucose metabolism increases with administration of L-Carnitine or ALCAR. ALCAR has the ability to cross the blood brain barrier and act as a powerful antioxidant and has neuroprotective properties and has shown some effects on mental clarity, peripheral nerve injury, heart benefits and energy levels. L-Carnitine is showing very good results with fatty liver disease and NASH(non alcoholic steatohepatitis). In a 24 week study 97% percent 74 patients with NASH responded with lowered liver enzymes, reduced c reactive protein, increased glucose and fat metabolism and lowered LDL and raised HDL when administered 1g 2/day with a 1600 calorie diet and full stretching regimen 3 times per week. The L-carnitine was well tolerated in all subjects, with no side effects. L-carnatine is safe, has virtually no side effects if taken within safe limits. It has also been known to reduce cravings for non complex carbohydrates like alcohol, sugar, breads, and the like.

Replied by Al
(Alvena, Sk., Canada)

I use acetyl-l-carnitine because of a recommendation to supplement alpha lipoic acid with it to make the alpha lipoic acid work better. On researching the acetyl-l-carnitine I found that it improves the absorption of alpha lipoic acid and other nutrients by stimulating and healing the mitochondria(hairs) in the digestive tract. I have also noticed that it contributes to pain reduction although alpha lipoic acid is the major pain reducer for peripheral neuropathy. I also found that grape seed extract helps with pain reduction among other things. The acetyl-l-carnitine must be taken on an empty stomach while alpha lipoic acid should be taken with food.

Replied by Jack
(New Haven, Ct)

In response to the comment above, when I saw the name carnitine I saw carn not car. Carn of course refers to meat (carnivorous) and red meat is the most common food source of carnitine. I think it has to be cardi to mean heart. Careful of those translations when it comes to your health.

Replied by Olddude
21 posts

L- carnitine reviews here are way old. Any new reviews on this supplement would be helpful.