l-Carnitine is used for:
Alzheimer's disease 

Cardiovascular disease 
Chronic fatigue syndrome 
Down's syndrome 
Heart disease
Heart arrythmias  
Heart attack 
High Blood pressure 

High cholesterol 
Irregular heartbeat 
Kidney disease 
Liver disease 

Muscular dystrophy 
Performance enhancement
Sperm motility

Studies on the beneficial effects of L-carnitine on the cardiovascular system began as early as 1937. L-camitine benefits the cardiovascular system in several ways. First, it is responsible for clearing fatty acids (triglycerides) out of the blood into the mitochondria (the energy powerhouse of the cells) to be broken down. Fatty acids are the major source for production of energy in the heart muscles. Therefore, heart muscles are particularly vulnerable to L-carnitine deficiency. Studies show that heart muscle levels of L-carnitine are decreased in the following conditions: angina pectoris (lack of oxygen to the heart causing chest pain), myocardial infarction (heart attack ) and chronic coronary insufficiency (weak heart muscle resulting in lack of oxygen to the body causing symptoms, such as breathlessness, fatigue, poor circulation). These studies have demonstrated the following important functions of L-carnitine: increasing cardiac output, improving heart muscle function, stimulating energy supply to the heart, increasing endurance, enhancing cardiac performance and regulating heart arrythmias.

L-Carnitine has been approved by the FDA under the name Carnitor as as a therapy for low energy levels, congestive heart disease, and other diseases associated with low cellular energy levels. Numerous published studies have shown that L-Carnitine is effective in treating a wide range of diseases including the neurological diseases of aging, immune dysfunction, and diabetic complications.
L-carnitine is synthesized in the body from the amino acids lysine and methionine. L-Carnitine is available from natural and synthetic sources. A prescription is not required to use L-Carnitine.

Benefits of L-Carnitine:

o Promotes normal growth and development
o Treats and possibly prevents some forms of cardiovascular disease
o Protects against muscle disease
o Helps build muscle
o Protects against liver disease
o Protects against diabetes
o Protects against kidney disease
o Aids in dieting

Why people may need additional L-Carnitine:

o Anyone with deficient protein or amino acids in their diet because L-carnitine requires 
   essential amino acids to be synthesized by the body
o Children, pregnant or breast-feeding women who are vegan vegetarians
o People with recent severe burns or injuries
o People on hemodialysis
o Premature infants

L-Carnitine Deficiency Symptoms:

o Muscle fatigue
o Cramps
o Changes in kidney function following exercise
o Premature aging
o Heartbeat irregularities in someone who has had a heart attack
o Angina