L-carnitine is an amino acid-like substance produced naturally by the human body in small quantities. Its name comes from the Greek word "carnus," meaning "meat."
With a name like that, it should come as no surprise that L-carnitine is abundant in red meat. It can also be found, at lower levels, in some nuts, grains and vegetables.
Lately, L-carnitine has gained popularity as a supplement. But what exactly does it do? Are there any side effects to taking it in a pill?
I'm glad you asked! Let's dive into the research.
One of L-carnitine's main roles is transporting fat into the mitochondria of muscle cells. There, the fat is burned away and turned into fuel.
Research has shown that when L-carnitine supplements are taken in conjunction with a healthy workout regimen, significantly more weight is lost than through exercise alone.
Research suggests that L-carnitine may be one of the most successful supplements for battling male infertility.
One study, published in the Urology Journal, found that men who received 25 mg of L-carnitine daily for 3 months saw their sperm count increase by 64%.
The subjects also had greater semen volume and mobility.
L-carnitine possesses antioxidant properties. Antioxidants prevent damage to cells by free radicals. This can help reduce the amount of time spent sick from a cold. It also reduces the severity of allergy symptoms.
Further, research has shown that L-carnitine combats suppression of the immune system, which occurs as a result of immune system disorders and conditions like psoriasis, diabetes and multiple sclerosis.
The Benefits of L-Carnitine
Fat Loss

Heart Health
A study by Mayo Clinic found that L-carnitine reduces one's risk of heart disease – the leading cause of death in the United States. The study involved a 3,629-strong control group. Researchers found that, when compared to a placebo, L-carnitine supplements reduced patients' risk of abnormal heart rhythm by 65%. It also reduced the risk of abnormal blood flow to the heart by 40%.Male Fertility

Diabetes Prevention and Treatment
A 1999 study published in the Journal of the American College of Nutrition found that L-carnitine greatly improves the way the human body handles glucose. High glucose levels are one of diabetes' main hallmarks. Another double-blind study found that in patients with existing diabetic neuropathy, L-carnitine supplementation three times daily was significantly effective at reducing symptom severity.Healthy Immune Function
