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Take L-carnitine twice or thrice daily when treating deficiencies. Divide your doses when treating valproic acid side effects. Treat heart disease twice daily. Manage thyroid symptoms twice daily. Treat male infertility once daily. Talk to your doctor about additional dosing inquiries.
Patients who lack a natural source of L-carnitine in the body are usually instructed to take two to three doses each day, with each dose containing 990 mg. They may take the supplement in tablet form or as an oral solution. If you are taking Depacon, Depakene, Depakote, VPA, or any other anti-seizure medication containing valproic acid, you should take a 50 to 100 mg of L-carnitine over the course of three to four doses each day. At most, you should receive no more than 3 grams of the amino acid per day. L-carnitine prescribed for the treatment of chest pain and congestive heart failure should be taken twice a day, and each dose should total 1 gram. Doctors who prescribe L-carnitine for patients who have already suffered a heart attack may instruct them to take a total of 2 to 6 grams throughout the course of a single day. Patients taking L-carnitine for hyperthyroidism should take 1 to 2 grams of the supplement two times a day. As a treatment against male infertility, L-carnitine should be taken once a day at a dose of 2 grams. Patients should also take a single daily dose of 1 gram L-acetyl-carnitine in conjunction with standard L-carnitine. If you take L-carnitine for any other reason, you will need to work with your doctor to find the right dose. In most cases, the usual dose for adults will be between 1 to 3 grams each day.  Never give L-carnitine to a child without your doctor's direct supervision. Infants with a low birth weight may receive L-carnitine intravenously or orally while at the hospital, but this treatment will usually stop before the child is sent home with the parents.