Supports fat metabolism
- Enhances energy levels and exercise performance and recovery
- Promotes fat burning
- Supports cardiovascular health and immunity
- Clinically effective dose and form
Non-medicinal Ingredients: Microcrystalline cellulose.
Most studies examining the clinical potential of L-carnitine have used exogenous, supplemental L-carnitine, and these have produced significant findings. These findings include human studies on anorexia nervosa, athletic performance, angina, ischemia, peripheral vascular disease, cardiomyopathy, myocardial infractions, hyperlipidemia, blood sugar instability, chronic fatigue syndrome, hepatitis, HIV, hyperthyroidism, and renal failure. In the latter, l-carnitine use is even recommended by the National Kidney Foundation for the alleviation of anemia associated with chronic renal failure. Anemia is a symptom targeted by L-carnitine supplementation in anorexia nervosa patients as well, improving weight gain, physical performance and appetite in combination with adenosylcobalamin (a cofactor of B12).
L-carnitine also increased walking time for peripheral vascular disease patients by nearly 80% in one double-blind, placebo-controlled study, while significantly increasing the survival rate among cardiogenic shock patients in two others. Long-term supplementation among heart patients have produced improvements in ejection fraction, Weber classification (a standardized test of cardiac performance), peak VO2 consumption, arterial and pulmonary blood pressure, and cardiac output. This is in addition to decreasing the mortality rate among myocardial infarction survivors by 12.5% after a year of L-carnitine supplementation at 4 grams daily, according to one study.
Blood Lipids and Blood Sugar Levels
Hyperlipidemia, a condition characterized by excess levels of fat in the blood (and a major force behind a poor HDL/LDL ratio of cholesterol), has also been targeted by L-carnitine research, with most studies showing 2 grams to be an effective daily dose for reducing triglyceride levels, either as an adjuvant or stand-alone therapy. Injections of L-carnitine have also been used among diabetics to successfully improve insulin sensitivity and alleviate the symptoms of diabetic neuropathy.
In patients with type 2 diabetes and hypercholesterolemia, 2g/day of L-carnitine significantly reduced Lp(a) (lipoprotein a) levels after 6 months from 29.6 to 23.4 mg/dL , compared to the placebo (27.8 to 26.7 mg/dL).
A study on type 2 diabetics over 3 months found that 2g/day of L-carnitine significantly improved the following parameters: oxidized LDL levels decreased by 15.1 compared with 3.0 U/L , LDL cholesterol decreased by 0.45 compared with 0.16 mmol/L, triglycerides decreased by 1.02 compared with 0.09 mmol/L , apolipoprotein A1 concentrations decreased by 0.12 compared with 0.03 mg/dL , apolipoprotein B-100 concentrations decreased by 0.13 compared with 0.04 mg/dL, thiobarbituric acid–reactive substance concentrations decreased by 1.92 compared with 0.05, and conjugated diene concentrations decreased by 0.72 compared with 0.11 in the placebo group.
Physical Activity and Sports Performance
One study found that 2g/day of L-carnitine L-tartrate minimized chemical damage to muscle tissue after exercise and enhanced the repair process in healthy, active 40-60 year old subjects. Specifically, improvements were seen in the biochemical markers of purine metabolism (ie, hypoxanthine, xanthine oxidase), free radical formation (malondialdehyde), muscle tissue disruption (myoglobin, creatine kinase), and muscle soreness after physical exertion.
One study on 16 long-distance runners receiving 2g/day of L-carnitine for one month showed significant increases in the pyruvate dehydrogenase complexes as well as increased performance and improved oxygen consumption during exercise. Another study on similar subjects also found improved activity in rotenone-sensitive NADH cytochrome c reductase, succinate cytochrome c reductase and cytochrome oxidase, respiratory chain enzymes in the mitochondria. Supplementation also resulted in increased total and free carnitine.
The effects on sports performance of L-Carnitine was measured in 110 top boy and girl athletes (rowers, kayak-canoers, swimmers, weightlifters and medium and long-distance runners) after an acute dose and after three weeks of consuming 1g per day orally. Significant improvements were found for FFA, triglycerides, lactic acid, evoked muscular potential, plasma carnitine, urine carnitine, and others. Free carnitine permits a larger quantitiy of FFA to enter the mitochondria and be used more as an energy source during both endurance and explosive efforts.
Energy and Fatigue
Studies using L-carnitine in chronic fatigue syndrome (CFS) have been successful. One such study was a crossover trial where l-carnitine was directly compared to the drug amantadine (often prescribed to treat CFS in Multiple Sclerosis [MS] patients). The results were that amantadine was poorly tolerated by the CFS patients, forcing 15 of the 30 to drop out of the treatment due to side effects – with no statistically significant improvements among those who remained. After a two-week washout period, the second eight-week phase of the study began – this time with L-carnitine as the intervention. Only one patient withdrew from this phase of the study, and significant improvements were recorded in 12 of the 18 standard parameters used to measure the degree of CFS symptoms.
One six-month study on 66 centenarians administered 2g of L-carnitine per day. The study noted significant changes in the following parameters: reduction of total fat mass, increases total muscular mass, and facilitates an increased capacity for physical and cognitive activity by reducing fatigue and improving cognitive functions. Total fat mass (-1.80 compared with 0.6 kg), total muscle mass (3.80 compared with 0.8 kg), plasma concentrations of total carnitine (12.60 compared with -1.70 μmol), plasma long-chain acylcarnitine (1.50 compared with -0.1 μmol), and plasma short-chain acylcarnitine (6.0 compared with -1.50 μmol). Significant differences were also found in physical fatigue (-4.10 compared with -1.10), mental fatigue (-2.70 compared with 0.30), fatigue severity (-23.60 compared with 1.90), and MMSE(4.1 compared with 0.6).
Liver & Kidney Health and Immunity
L-carnitine has also been linked to liver health, particularly through its ability to control serum ammonia levels. In fact, several studies with hepatic encephalopathy patients have confirmed not only this ability on the part of l-carnitine, but also the ability to improve mental function in this condition as measured by NCT-A, an accepted psychometric test for mental status in such patients. As mentioned earlier, l-carnitine supplementation in patients with renal failure has been so extensive that its use has even been advocated by the National Kidney Foundation. In one eight-month study, only 3 grams of intravenously administered l-carnitine per week was required to improve left ventricular ejection fraction (which is taxed heavily during renal failure) by more than 30%. L-carnitine supplementation has also been studied in HIV-positive patients, both as stand-alone and adjuvant therapy; l-carnitine enhances CD4 immune cells in the former while protecting them in the latter, thus effectively making l-carnitine an immune system enhancer.
Hyperthyroidism and male infertility have also been subjects for l-carnitine supplementation. Since endogenous l-carnitine plays a marginally inhibitory role in the activity of thyroid hormones, it was hypothesized that increasing l-carnitine levels via supplementation would have a positive effect on hyperthyroid patients. The hypothesis proved correct in at least one study, where daily doses as low as 2 grams (for six months) prevented and reversed symptoms of hyperthyroidism, including the latter’s effect on bone mineralization.
Male Fertility and Prenatal Health
L-carnitine has also been linked to increased sperm counts, leading to a number of studies with it among infertile males. These studies, which used 2-3 grams of l-carnitine daily in periods generally ranging from two to four months, were successful in increasing both sperm count and motility. Finally, there is also some evidence to suggest that l-carnitine might be useful for women during prenatal periods; one short-term study (five days) showed that 4 grams of l-carnitine combined with the drug betamethasone reduced the incidence of respiratory distress syndrome as well as mortality in premature newborns.