By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.

L-carnitine is a water-soluble amino acid-like compound found in foods such as lamb, beef, red meat, and pork. Your body also endogenously produces L-carnitine with the help of two amino acids – lysine and methionine – as well as Vitamins C and B6, iron, and niacin. In order to avoid L-carnitine deficiency, vegetarians should supplement and/or combine such foods as beans and rice, which contain lysine and methionine, respectively.

Like coenzyme Q10 (CoQ10), L-carnitine is also considered an antioxidant that protects your heart and blood vessels from oxidative stress that can lead to CAD. It helps prevent damage from toxic by-products which are generated through the metabolism of fats. As a vasodilator, L-carnitine opens blood vessels and increases blood flow to your heart, muscles and other tissues, resulting in better overall oxygen use by your body.

As a key nutrient for cardiac tissue, L-carnitine can serve as adjunctive treatment for conditions like angina, congestive heart failure (CHF), ventricular arrhythmia, and cholesterol disorders. It may be safely and effectively taken in combination with beta-blockers, ACE inhibitors, and other cardiac drugs for a more full-spectrum approach to symptom relief.

Health professionals can measure levels of L-carnitine in the blood to determine whether deficiency is at issue. Unfortunately, the body’s need for L-carnitine becomes most obvious in situations like heart disease, where the heart is energy-starved and may also lack CoQ10 and D-ribose. L-carnitine deficiency is also associated with renal insufficiency, lipid metabolic disorders and mitochondrial disorders.

Supplementation with L-carnitine is generally recommended for vegetarians or others who don’t get enough nutrients in their diets from which to synthesize it, and people over the age of forty. People taking pharmaceutical drugs like anticonvulsants, or patients with liver disease, kidney disease, or genetic defects related to L-carnitine metabolism may also lack L-carnitine. Classified as myopathic (reduced skeletal muscle concentrations) or systemic, L-carnitine deficiencies may respectively manifest through overt symptoms such as muscle cramps, muscle fatigue, and muscle pain following exercise, or subtle systemic symptoms such as impaired ventricular function.

L-carnitine is not very bioavailable. As there are various forms of L-carnitine, supplementation with a broad-spectrum product that contains L-carnitine fumarate, acetyl-L-carnitine, and propionyl-L-carnitine is the optimal choice. Because L-carnitine doesn’t get fully absorbed when taken orally, ingesting it in smaller doses 3 times per day on an empty stomach is the preferred method; I recommend starting with a low dose, then gradually increasing it until a desired effect is achieved:

  • 400 – 800 mg daily (especially for vegetarians) to prevent deficiency;
  • 500 -1,000 mg two-to-three times daily if you have coronary artery disease or angina;
  • 1 – 2 grams (sometimes up to 3 grams) daily for arrhythmia; and
  • 2 – 4 grams daily for congestive heart failure or following a heart attack.

© 2010 HeartMD Institute. All rights reserved.

Leave a Reply


  1. Andy

    on October 18, 2013 at 8:49 am

    What do you think of latest study that shows L Carnitine can puncture an artery because of increased levels of TMAO?

    Thank you.

  2. Joe Prisco

    on May 27, 2014 at 3:23 am

    Dear Dr. Sinatra, At a Kripalu workshop in the recent past, you advised
    me to take your broad spectrum Carnitine. Looking to order more this
    Memorial Day, I was quite disturbed to learn that it was discontinued
    as of this March. Please advise if there is another product,such as the
    Life Extension- Optimized Carnitine, that you would recommend.
    Thanks, Joe

  3. HMDI Editors

    on May 29, 2014 at 3:32 pm

    While a daily dose of Dr. Sinatra’s Omega-Q Plus product contains 200 mg L-carnitine (as fumarate), if Dr. Sinatra advised you to take his (now discontinued) broad spectrum carnitine, your likely best option is to follow his advice and find a carnitine that is broad-spectrum and contains multiple forms of carnitine for the best protection; Dr. Sinatra doesn’t recommend any brands in particular. You should be able to find such a product via Amazon.com or your local nutritional products store. We hope you’re not too inconvenienced by making this change and wish you the best of health and happiness.

  4. melvin

    on March 16, 2015 at 9:30 pm

    I also would like to hear a response on this question. Instead you respond only to the supplement question. I know this is more complicated but surely being a cardiologist you could point to something that debunks this or supports it.

  5. Mort

    on March 25, 2015 at 5:49 pm

    I just read a Dr. Oz statement from 2010 that a person should not take Acetyl L-Carnitine at all. I have been taking this supplement in the 500 mg dosage for 20 years along with 60mg of C-Q10. I also take Blood pressure medicine ,and avorstatin drugs plus an aspirin 81mg a day. Please let me know if I should continue with the L.

  6. Laurie Eisler

    on April 25, 2015 at 7:13 pm

    I’m concerned about L-Carnitine’s effect on my Hashimoto’s hypothyroid, which I don’t want blocked further. I have CHF and am already taking Ubiqunone, Dr. S’s broad-spectrum Mag, and D-Ribose powder. I’d like to add the L-Carnitine, but please advise. I’ve tried calling and haven’t received a call-back as promised! Thanks.

  7. HMDI Editor

    on April 28, 2015 at 1:41 pm

    Hi Laurie, Please consult with the doctor who is managing your condition about whether you should take L-carnitine as a supplement or as an ingredient in a supplement.

  8. Fx

    on November 4, 2015 at 9:56 am

    diastolic heart fail grade 1 l-carnitine fumarate dosage ?

  9. Gloria

    on March 23, 2019 at 12:42 pm

    Dear Dr. Sinatra, I bought your latest revised book because my husband was having metabolic systems and I want to thank you because in a course of 6 months his exercise tolerance and energy levels are now outstanding. So first, from the bottom of my heart thank you for all your good work. Now I decided to try the L Carnitine to add to my supplements. I was taking 1500 mg for about 6 months. I went for my biannual blood work (forget to tell you I am 74 and my husband 77 and we are on no perscriptions, except I take armour thyroid) my free T4 went down to a .8 from a 3 and my tsh went up to 6.2 from a 4. I take the carnitine 10 hours apart from my armour. I am off the carnitine now until my numbers lower. I am hoping that I can at least take 500 mg a day for health and maybe the original dose was too high. Thank you for taking the time in reading my message and thank you for your book that is a God send because traditional cardiologists would not have even taken this approach. Gloria

  10. Edwin S

    on May 5, 2019 at 6:22 am

    Dear Dr. Sinatra, since I did not find an answer to the question from Andy (2013) re TMAO I would appreciate your comment.
    According to the Clevenland Clinic publication in the New England Journal of Medicine 2013 certain intestine bacteria types should be responsible for the development of TMAO and subequently to the building of plaques in the blood vessels.
    Do you have information which types of bacterias are to be considered.
    A stool analyis could than give further hints whether the supplementation with carnitine is reasonable.
    My age is 79, I received a stent at RCX RM1 last year and as medication I am taking Atorvastatin 20 mg + 100 mg ASS (additionally some supplements: Q10. Vitamin B-complex, Omega 3, Carnitine, Ribose, Arginine, Curcumine)
    May I thank you in advance for your reply.
    Edwin Stadler

  11. Nutrindo Ideias

    on January 7, 2020 at 6:43 pm

    Very interesting article about carnitine. Really well written.

  12. Marlene

    on February 13, 2020 at 9:00 am

    Was told I have chronic kidney disease stage 3 I was taking Omega Q pluss 100 with resveratol but the kidney Dr said i was to stop all supplements I did but I want to restart them I see him today so I will ask him but.
    Is there anything in this product that would hurt Kidneys from what i have read it would help them I took a lot of supplements of yours and miss them

  13. HeartMD Editor

    on March 13, 2020 at 6:35 pm

    Hi Marlene, Your MD is correct about caution with supplements if you have kidney disease. Minerals and electrolytes such as potassium and magnesium can build up to unhealthy levels if the kidneys cannot clear them.
    If you were Dr. Sinatra’s patient, he would support taking Omega Q Plus. It may even help your kidneys.

  14. Marlene Glidden

    on March 13, 2020 at 9:01 pm

    I got theKidney Dra permisson to take the omega with resveratol so I just ordered another supply and he said i could take a multiple vitamin so I chose to order Dr Sinatras womens vitamins rather than some in a drug store Did not show the dr those and don’t see him for 6 months so will see what happens then .Thanks so much for answering me

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