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GNC Pro Performance® Liquid L-Carnitine

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Description
  • L-Carnitine is a non-essential amino acid that can be synthesized by the body.
  • Amino acids are the building blocks of protein and help fuel skeletal muscles.*
  • Found abundantly in red meats, carnitine is stored in skeletal muscles where it is needed to transform fatty acids into energy for muscular activity.
  • Carnitine also facilitates the metabolism of long-chain fatty acids.*
  • Recently, deficiencies of carnitine have been seen in people who avoid eating red meats in the diet.
  • Each serving contains 1000 mg of Cherry flavored L-Carnitine.

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Supplement Facts

As a dietary supplement, take 2 tablespons daily.

Serving Size 30 milliliters
Servings Per Container 15
Amount Per Serving % DV
Calories 50.00
Sodium 5.00 mg 0%
Pantothenic Acid 15.00 mg 150%
Pantothenic Acid 15.00 mg 150%
L-Carnitine 1000.00 mg **
L-Carnitine 1000.00 mg **
** Daily Value (DV) not established

Other Ingredients: Purified Water, Purified Water, Natural Vegetable Glycerine, Natural Vegetable Glycerine, L-Carnitine, L-Carnitine, Sodium Benzoate, Sodium Benzoate, Potassium Sorbate, Potassium Sorbate, Citric Acid, Citric Acid, Natural Flavors, Natural Flavors, Calcium Pantothenate, Calcium Pantothenate

No Sugar, No Starch, No Wheat, Yeast Free

Storage Instructions: Store in a cool dry place.

Warning: After opening, keep tightly closed in refrigerator or other cool place.

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Health Notes

L-Carnitine

L-Carnitine
This nutrient has been used in connection with the following health goals
  • Reliable and relatively consistent scientific data showing a substantial health benefit.
  • Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
  • For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary "Star-Rating" system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:

Angina
Dose: 1 gram two or three times per day
Supplementing with L-carnitine may improve heart function and ease angina symptoms.(more)
Congestive Heart Failure
Dose: 500 mg two to three times per day with a doctor's supervision
Supplementing with L-carnitine can improve heart function and exercise capacity and reduce heart muscle damage due to insufficient oxygen.(more)
Heart Attack
Dose: 2 grams daily
Taking L-carnitine may help reduce damage and complications following a heart attack.(more)
Intermittent Claudication
Dose: 2 grams daily
In double-blind trials, supplementing with either L-carnitine or propionyl-L-carnitine (a form of L-carnitine) has increased walking distance in people with intermittent claudication.(more)
High Triglycerides
Dose: 1 to 3 grams daily
Supplementing with L-carnitine may help normalize triglyceride levels.(more)
Intermittent Claudication
Dose: 2 grams a day of proprionyl-L-carnitine
In double-blind trials, supplementation with either L-carnitine or propionyl-L-carnitine (a form of L-carnitine) has increased walking distance in people with intermittent claudication.(more)
Chronic Obstructive Pulmonary Disease
Dose: 2 grams taken twice per day
Studies have shown that when L-carnitine is given to people with chronic lung disease, breathing during exercise improves.(more)
High Cholesterol
Dose: Refer to label instructions
Some preliminary trials report that L-carnitine reduces serum cholesterol and raises HDL cholesterol.(more)
Mitral Valve Prolapse
Dose: Refer to label instructions
In one report, deficient levels of L-carnitine were found in five people with MVP. One person was given L-carnitine and experienced a complete resolution of MVP symptoms.(more)
Cardiomyopathy
Dose: Refer to label instructions
Inherited forms of cardiomyopathy seen in children may be responsive to L-carnitine.(more)
Raynaud's Disease
Dose: Refer to label instructions
In one study, people with Raynaud's disease who were given L-carnitine showed less blood-vessel spasm in their fingers in response to cold exposure.(more)
Erectile Dysfunction
Dose: 2 grams of each daily
In one study, supplementing with the combination of propionyl-L-carnitine (a form of L-carnitine) and acetyl-L-carnitine significantly improved erectile function in elderly men.(more)
Male Infertility
Dose: 3 grams daily
L-carnitine appears to be necessary for normal functioning of sperm cells. Supplementing with it may improve sperm motility.(more)
Attention Deficit-Hyperactivity Disorder
Dose: 100 mg per 2.2 lbs (1 kg) of body weight daily, up to a maximum of 4 grams per day
In a double-blind study, supplementing with L-carnitine resulted in improvement in 54% of a group of boys with ADHD, compared with a 13% response rate in the placebo group.(more)
Autism
Dose: 50 mg per kilogram of body weight per day (half in the morning, half in the evening)
In a double-blind trial, supplementing with L-carnitine resulted in a modest improvement in disease severity in children with autism spectrum disorders. (more)
Type 2 Diabetes
Dose: 0.25 mg per 2.2 lbs (1 kg) of body weight
Supplementing with L-carnitine may reduce cholesterol and triglyceride levels in people with diabetes.(more)
Type 1 Diabetes
Dose: 0.25 mg per 2.2 lbs (1 kg) of body weight
Supplementing with L-carnitine may reduce cholesterol and triglyceride levels in people with diabetes.(more)
Erectile Dysfunction
Dose: 2 grams of each daily
In one study, supplementing with the combination of propionyl-L-carnitine (a form of L-carnitine) and acetyl-L-carnitine significantly improved erectile function in elderly men.(more)
Chronic Fatigue Syndrome
Dose: 1 gram three times daily
L-carnitine is an important nutrient for energy production. Supplementation can make up for a possible deficiency.(more)
Athletic Performance
Dose: Refer to label instructions
L-carnitine has been popular as a potential aid in improving athletic performance because of its role in converting fat to energy. Some studies have found that it improves certain measures of muscle physiology.(more)
Obesity
Dose: Refer to label instructions
The amino acid L-carnitine is thought to be potentially helpful for weight loss because of its role in fat metabolism.(more)
Asthma
Dose: Refer to label instructions
In a double-blind trial, supplementing with L-carnitine improved lung function and overall asthma control, compared with a placebo, in children with asthma. (more)
Sprains and Strains and Exercise-Related Muscle Injury
Dose: 3 grams per day
One trial showed that people who take L-carnitine for three weeks before engaging in an exercise regimen are less likely to experience muscle soreness.(more)
Angina
Dose: 1 gram two or three times per day

L-carnitine is an amino acid needed to transport fats into the mitochondria (the place in the cell where fats are turned into energy). Adequate energy production is essential for normal heart function. Several studies using 1 gram of L-carnitine two to three times per day showed an improvement in heart function and a reduction in symptoms of angina.1, 2, 3Coenzyme Q10 also contributes to the energy-making mechanisms of the heart. Angina patients given 150 mg of coenzyme Q10 each day have experienced greater ability to exercise without experiencing chest pain.4 This has been confirmed in independent investigations.5

References

1. Cherchi A, Lai C, Angelino F, et al. Effects of L-carnitine on exercise tolerance in chronic stable angina: A multicenter, double-blind, randomized, placebo-controlled crossover study. Int J Clin Pharmacol Ther Toxicol 1985;23:569-72.

2. Canale C, Terrachini V, Biagini A, et al. Bicycle ergometer and echocardiographic study in healthy subjects and patients with angina pectoris after administration of L-carnitine: Semiautomatic computerized analysis of M-mode tracing. Int J Clin Pharmacol Ther Toxicol 1988;26:221-4.

3. Cacciatore L, Cerio R, et al. The therapeutic effect of L-carnitine in patients with exercise-induced stable angina: A controlled study. Drugs Exp Clin Res 1991;17:225-35.

4. Kamikawa T, Kobayashi A, Yamashita T, et al. Effects of coenzyme Q10 on exercise tolerance in chronic stable angina pectoris. Am J Cardiol 1985;56:247.

5. Mortensen SA. Perspectives on therapy of cardiovascular diseases with coenzyme Q10 (ubiquinone). Clin Investig 1993;71:S116-23 [review].

Congestive Heart Failure
Dose: 500 mg two to three times per day with a doctor's supervision

People with CHF have insufficient oxygenation of the heart, which can damage the heart muscle. Such damage may be reduced by taking L-carnitine supplements.1 L-carnitine is a natural substance made from the amino acidslysine and methionine. Levels of L-carnitine are low in people with CHF;2 therefore, many doctors recommend that those with CHF take 500 mg of L-carnitine two to three times per day.

Most L-carnitine/CHF research has used a modified form of the supplement called propionyl-L-carnitine (PC). In one double-blind trial, people using 500 mg of PC per day had a 26% increase in exercise capacity after six months.3 In double-blind research, other indices of heart function have also improved after taking 1 gram of PC twice per day.4 It remains unclear whether propionyl-L-carnitine has unique advantages over L-carnitine, as limited research in animals and humans has also shown very promising effects of the more common L-carnitine.5

References

1. Bartels GL, Remme WJ, Pillay M, et al. Effects of L-propionylcarnitine on ischemia-induced myocardial dysfunction in men with angina pectoris. Am J Cardiol 1994;74:125-30.

2. Suzuki Y, Masumura Y, Kobayashi A, et al. Myocardial carnitine deficiency in chronic heart failure. Lancet 1982;i:116 (letter).

3. Mancini M, Rengo F, Lingetti M, et al. Controlled study on the therapeutic efficacy of propionyl-L-carnitine in patients with congestive heart failure. Arzneimittelforschung 1992;42:1101-4.

4. Pucciarelli G, Mastursi M, Latte S, et al. The clinical and hemodynamic effects of propionyl-L-carnitine in the treatment of congestive heart failure. Clin Ther 1992;141:379-84.

5. Kobayashi A, Masumura Y, Yamazaki N. L-carnitine treatment for congestive heart failure-experimental and clinical study. Jpn Circ J 1992;56:86-94.

Heart Attack
Dose: 2 grams dailyL-carnitine is an amino acid important for transporting fats that can be turned into energy in the heart. Clinical trials have reported that taking L-carnitine (4-6 grams per day) increases the chance of surviving a heart attack.1, 2, 3 In one double-blind trial, individuals with suspected heart attack were given 2 grams of L-carnitine per day for 28 days.4 At the completion of this study, infarct size, as well as the number of nonfatal heart attacks, was lower in the group receiving L-carnitine versus the placebo group. Double-blind research using L-carnitine intravenously also shows promise.5
References

1. Davini P, Bigalli A, Lamanna F, Boem A. Controlled study on L-carnitine therapeutic efficacy in post-infarction. Drugs Exp Clin Res 1992;18:355-65.

2. De Pasquale B, Righetti G, Menotti A. L-carnitine for the treatment of acute myocardial infarct. Cardiologia 1990;35:591-6 [in Italian].

3. Iliceto S, Scrutinio D, Bruzzi P, et al. Effects of L-carnitine administration on left ventricular remodeling after acute anterior. J Am Coll Cardiol 1995;26:380-7.

4. Singh RB, Niaz MA, Agarwal P, et al. A randomised double-blind placebo-controlled trial of L-carnitine in suspected acute myocardial infarction. Postgrad Med J 1996;72:45-50.

5. Martina B, Zuber M, Weiss P, et al. Anti-arrhythmia treatment using L-carnitine in acute myocardial infarct. Schweiz Med Wochenschr 1992;122:1352-5 [in German].

Intermittent Claudication
Dose: 2 grams dailyIn double-blind trials, supplementation with L-carnitine and propionyl-L-carnitine (a form of L-carnitine) has increased walking distance in people with intermitting claudication. Walking distance was 75% greater after three weeks of L-carnitine supplementation (2 grams taken twice per day), than after supplementation with a placebo, a statistically significant difference. In the study using propionyl-L-carnitine, improvement occurred on in the those who could not walk 250 meters to begin with. In that group, maximum walking distance increase by 78% with propionyl-L-carnitine supplementation compared with a 44% increase in the placebo group, also a statistically significant difference. The amount of propionyl-L-carnitine used was 1 gram per day, increasing to 2 grams per day after two months, and 3 grams per day after an additional two months, if needed. The results of this trial have been confirmed in a large European trial.
High Triglycerides
Dose: 1 to 3 grams daily

L-carnitine is another supplement that has lowered TGs in several clinical trials.1, 2 However, the effect of carnitine is unpredictable, and some individuals have experienced an increase in triglyceride levels after receiving this supplement.3 Some doctors recommend 1-3 grams of carnitine per day, in the form known as L-carnitine.

References

1. Pola P, Savi L, Grilli M, et al. Carnitine in the therapy of dyslipidemic patients. Curr Ther Res 1980;27:208-16.

2. Abdel-Aziz MT, Abdou MS, Soliman K, et al. Effect of carnitine on blood lipid pattern in diabetic patients. Nutr Rep Int 1984;29:1071-9.

3. Anonymous. Carnitine, clue or cure? Lancet 1982;2:1027-8.

Intermittent Claudication
Dose: 2 grams a day of proprionyl-L-carnitine

In double-blind trials, supplementation with either L-carnitine and propionyl-L-carnitine (a form of L-carnitine) has increased walking distance in people with intermittent claudication. Walking distance was 75% greater after three weeks of L-carnitine supplementation (2 grams taken twice per day), than after supplementation with a placebo, a statistically significant difference.1 In the study using propionyl-L-carnitine, improvement occurred only in those who could not walk 250 meters to begin with. In that group, maximum walking distance increased by 78% with propionyl-L-carnitine supplementation compared with a 44% increase in the placebo group, also a statistically significant difference.2 The amount of propionyl-L-carnitine used was 1 gram per day, increasing to 2 grams per day after two months, and 3 grams per day after an additional two months, if needed. The results of this trial have been confirmed in a large European trial.3

References

1. Brevetti G, Chiariello M, Ferulano G, et al. Increases in walking distance in patients with peripheral vascular disease treated with L-carnitine: a double-blind, cross-over study. Circulation 1988;77:767-73.

2. Brevetti G, Perna S, Sabba C, et al. Effect of propionyl-L-carnitine on quality of life in intermittent claudication. Am J Cardiol 1997;79:777-80.

3. Brevetti G, Diehm C, Lambert D. European multicenter study on propionyl-L-carnitine in intermittent claudication. J Am Coll Cardiol 1999;34:1618-24.

Chronic Obstructive Pulmonary Disease
Dose: 2 grams taken twice per day

L-carnitine has been given to people with chronic lung disease in trials investigating how the body responds to exercise.1, 2 In these double-blind trials, 2 grams of L-carnitine, taken twice daily for two to four weeks, led to positive changes in breathing response to exercise.

References

1. Dal Negro R, Pomari G, Zoccatelli O, Turco P. L-carnitine and rehabilitative respiratory physiokinesitherapy: metabolic and ventilatory response in chronic respiratory insufficiency. Int J Clin Pharmacol Ther Toxicol 1986;24:453-6.

2. Dal Negro R, Turco P, Pomari C, De Conti F. Effects of L-carnitine on physical performance in chronic respiratory insufficiency. Int J Clin Pharmacol Ther Toxicol 1988;26:269-72.

High Cholesterol
Dose: Refer to label instructionsL-carnitine is needed by heart muscle to utilize fat for energy. Some,1, 2 but not all, preliminary trials report that carnitine reduces serum cholesterol.3 HDL cholesterol has also increased in response to carnitine supplementation.4, 5 People have been reported in controlled research to stand a greater chance of surviving a heart attack if they are given L-carnitine supplements.6 Most trials have used 1 to 4 grams of carnitine per day.
References

1. Pola P, Savi L, Grilli M, et al. Carnitine in the therapy of dyslipidemic patients. Curr Ther Res 1980;27:208-16.

2. Stefanutti C, Vivenzio A, Lucani G, et al. Effect of L-carnitine on plasma lipoprotein fatty acids pattern in patients with primary hyperlipoproteinemia. Clin Ter 1998;149:115-9.

3. Maebashi M, Kawamura N, Sato M, et al. Lipid-lowering effect of carnitine in patients with type-IV hyperlipoproteinaemia. Lancet 1978;ii:805-7.

4. Rossi CS, Siliprandi N. Effect of carnitine on serum HDL-cholesterol: report of two cases. Johns Hopkins Med J 1982;150:51-4.

5. Pola P, Savi L, Grilli M, et al. Carnitine in the therapy of dyslipidemic patients. Curr Ther Res 1980;27:208-16.

6. Davini P, Bigalli A, Lamanna F, Boem A. Controlled study on L-carnitine therapeutic efficacy in post-infarction. Drugs Exp Clin Res 1992;18:355-65.

Mitral Valve Prolapse
Dose: Refer to label instructions

In one report, deficient levels of L-carnitine were found in five consecutive people with MVP.1 One of these people was given L-carnitine (1 gram three times per day for four months) and experienced a complete resolution of the symptoms associated with MVP.

References

1. Trivellato M, de Palo E, Gatti R, et al. Carnitine deficiency as the possible etiology of idiopathic mitral valve prolapse: case study with speculative annotation. Texas Heart Inst J 1984;11:370-6.

Cardiomyopathy
Dose: Refer to label instructions

Deficiency of L-carnitine, an amino acid, is associated with the development of some forms of cardiomyopathy.1 Inherited forms of cardiomyopathy seen in children may be the most responsive to therapy with L-carnitine.2, 3 Whether carnitine supplementation helps the average person with cardiomyopathy remains unknown. Nonetheless, some doctors recommend 1 to 3 grams of carnitine per day for adults of average weight.

References

1. Paulson DJ. Carnitine deficiency-induced cardiomyopathy. Mol Cell Biochem 1998;180(1-2):33-41.

2. Winter S, Jue K, Prochazka J, et al. The role of L-carnitine in pediatric cardiomyopathy. J Child Neurol 1995;10 Suppl 2:S45-51.

3. Kothari SS, Sharma M. L-carnitine in children with idiopathic dilated cardiomyopathy. Indian Heart J 1998;50:59-61.

Raynaud's Disease
Dose: Refer to label instructions

In one study, 12 people with Raynaud's disease were given L-carnitine (1 gram three times a day) for 20 days.1 After receiving L-carnitine, these people showed less blood-vessel spasm in their fingers in response to cold exposure.

References

1. Gasser P, Martina B, Dubler B. Reaction of capillary blood cell velocity in nailfold capillaries to L-carnitine in patients with vasospastic disease. Drugs Exp Clin Res 1997;23:39-43.

Erectile Dysfunction
Dose: 2 grams of each daily

In a double-blind study, supplementing with the combination of propionyl-L-carnitine (a form of L-carnitine) and acetyl-L-carnitine (2 grams of each per day) for six months significantly improved erectile function in elderly men with erectile dysfunction associated with low testosterone levels. Propionyl-L-carnitine and acetyl-L-carnitine were significantly more effective than testosterone treatment.1

References

1. Cavallini G, Caracciolo S, Vitali G, et al. Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology2004;63:641-6.

Male Infertility
Dose: 3 grams daily

L-carnitine is a substance made in the body and also found in supplements and some foods (such as meat). It appears to be necessary for normal functioning of sperm cells. In preliminary studies, supplementing with 3-4 grams per day for four months helped to normalize sperm motility in men with low sperm quality.1, 2 While the majority of clinical trials have used L-carnitine, one preliminary trial found that acetylcarnitine (4 grams per day) may also prove useful for treatment of male infertility caused by low quantities of immobile sperm.3

References

1. Costa M, Canale D, Filicori M, et al. L-carnitine in idiopathic asthenozoospermia: a multicenter study. Andrologia 1994;26:155-9.

2. Vitali G, Parente R, Melotti C. Carnitine supplementation in human idiopathic asthenospermia: clinical results. Drugs Exp Clin Res 1995;21:157-9.

3. Moncada ML, Vicari E, Cimino C, et al. Effect of acetylcarnitine treatment in oligoasthenospermic patients. Acta Europaea Fertilitatis 1992;23:221-4.

Attention Deficit-Hyperactivity Disorder
Dose: 100 mg per 2.2 lbs (1 kg) of body weight daily, up to a maximum of 4 grams per day

In a double-blind study, supplementation with L-carnitine for eight weeks resulted in clinical improvement in 54% of a group of boys with ADHD, compared with a 13% response rate in the placebo group.1 The amount of L-carnitine used in this study was 100 mg per 2.2 pounds of body weight per day, with a maximum of 4 grams per day. No adverse effects were seen, although one child developed an unpleasant body odor while taking L-carnitine. Researchers have found that this uncommon side effect of L-carnitine can be prevented by supplementing with riboflavin. Although no serious side effects were seen in this study, the safety of long-term L-carnitine supplementation in children has not been well studied. This treatment should, therefore, be monitored by a physician.

References

1. Van Oudheusden LJ, Scholte HR. Efficacy of carnitine in the treatment of children with attention-deficit hyperactivity disorder. Prostaglandins Leukot Essent Fatty Acids 2002;67:33-8.

Autism
Dose: 50 mg per kilogram of body weight per day (half in the morning, half in the evening) In a double-blind trial, supplementing with L-carnitine resulted in a modest improvement in disease severity in children with autism spectrum disorders. The amount of L-carnitine used was 50 mg per kilogram of body weight per day (half in the morning and half in the evening) for three months.1
References

1. Geier DA, Kern JK, Davis G, et al. A prospective double-blind, randomized clinical trial of levocarnitine to treat autism spectrum disorders. Med Sci Monit 2011;17:PI15-23.

Type 2 Diabetes
Dose: 0.25 mg per 2.2 lbs (1 kg) of body weight

L-carnitine is an amino acid needed to properly utilize fat for energy. When people with diabetes were given DL-carnitine (0.5 mg per 2.2 pounds of body weight), high blood levels of fats-both cholesterol and triglycerides-dropped 25 to 39% in just ten days in one trial.1

References

1. Abdel-Aziz MT, Abdou MS, Soliman K, et al. Effect of carnitine on blood lipid pattern in diabetic patients. Nutr Rep Int 1984;29:1071-9.

Type 1 Diabetes
Dose: 0.25 mg per 2.2 lbs (1 kg) of body weightL-carnitine is an amino acid needed to properly utilize fat for energy. When people with diabetes were given L-carnitine (0.5 mg per 2.2 pounds of body weight), high blood levels of fats-both cholesterol and triglycerides-dropped 25 to 39% in just ten days in one trial.1
References

1. Abdel-Aziz MT, Abdou MS, Soliman K, et al. Effect of carnitine on blood lipid pattern in diabetic patients. Nutr Rep Int 1984;29:1071-9.

Erectile Dysfunction
Dose: 2 grams of each daily

In a double-blind study, supplementing with the combination of propionyl-L-carnitine (a form of L-carnitine) and acetyl-L-carnitine (2 grams of each per day) for six months significantly improved erectile function in elderly men with erectile dysfunction associated with low testosterone levels. Propionyl-L-carnitine and acetyl-L-carnitine were significantly more effective than testosterone treatment.1

References

1. Cavallini G, Caracciolo S, Vitali G, et al. Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology2004;63:641-6.

Chronic Fatigue Syndrome
Dose: 1 gram three times daily

L-carnitine is required for energy production in the powerhouses of cells (the mitochondria). There may be a problem in the mitochondria in people with CFS. Deficiency of carnitine has been seen in some CFS sufferers.1 One gram of carnitine taken three times daily for eight weeks led to improvement in CFS symptoms in one preliminary trial.2 Supplementation with 6 grams of L-carnitine per day for four weeks also improved fatigue in a preliminary study of patients with advanced cancer.3 Similar improvements were seen in another study of patients with advanced cancer given up to 3 grams of L-carnitine per day for one week.4

References

1. Kuratsune H, Yamaguti K, Takahashi M, et al. Acylcarnitine deficiency in chronic fatigue syndrome. Clin Infect Dis 1994;18(1 suppl):S62-7.

2. Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of chronic fatigue syndrome. Neuropsychobiology 1997;35:16-23.

3. Gramignano G, Lusso MR, Madeddu C, et al. Efficacy of L-carnitine administration on fatigue, nutritional status, oxidative stress, and related quality of life in 12 advanced cancer patients undergoing anticancer therapy. Nutrition2006;22:136-45.

4. Cruciani RA, Dvorkin E, Homel P, et al. Safety, tolerability and symptom outcomes associated with L-carnitine supplementation in patients with cancer, fatigue, and carnitine deficiency: a phase I/II study. J Pain Symptom Manage 2006;32:551-9.

Athletic Performance
Dose: Refer to label instructions

L-carnitine, which is normally manufactured by the human body, has been popular as a potential ergogenic aid (i.e., having the ability to increase work capacity), because of its role in the conversion of fat to energy.1 However, while some studies have found that L-carnitine improves certain measures of muscle physiology, research on the effects of 2 to 4 grams of L-carnitine per day on performance have produced inconsistent results.2 L-carnitine may be effective in certain intense exercise activities leading to exhaustion,3 but recent studies have reported that L-carnitine supplementation does not benefit non-exhaustive or even marathon-level endurance exercise,4, 5 anaerobic performance,6 or lean body mass in weight lifters.7

References

1. Cerretelli P, Marconi C. L-carnitine supplementation in humans. The effects on physical performance. Int J Sports Med 1990;11:1-14 [review].

2. Heinonen OJ. Carnitine and physical exercise. Sports Med 1996;22:109-32 [review].

3. Bucci LR. Nutrients as ergogenic aids for sports and exercise. Boca Raton, FL: CRC Press, 1993, 47-52 [review].

4. Colombani P, Wenk C, Kunz I, et al. Effects of L-carnitine supplementation on physical performance and energy metabolism of endurance-trained athletes: a double blind crossover field study. Eur J Appl Physiol 1996;73:434-9.

5. Decombaz J, Deriaz O, Acheson K, et al. Effect of L-carnitine on submaximal exercise metabolism after depletion of muscle glycogen. Med Sci Sports Exerc 1993;25:733-40.

6. Trappe SW, Costill DL, Goodpaster B, et al. The effects of L-carnitine supplementation on performance during interval swimming. Int J Sports Med 1994;15:181-5.

7. Green RE, Levine AM, Gunning MJ. The effect of L-carnitine supplementation on lean body mass in male amateur body builders. J Am Dietet Assoc 1997;(suppl):A-72 [abstract].

Obesity
Dose: Refer to label instructionsThe amino acid L-carnitine is thought to be potentially helpful for weight loss because of its role in fat metabolism. In a preliminary study of overweight adolescents participating in a diet and exercise program, those who took 1,000mg of L-carnitine per day for three months lost significantly more weight than those who took a placebo.1 A weakness of this trial, however, was the fact that the average starting body weight differed considerably between the two groups. A double-blind trial found that adding 4,000 mg of L-carnitine per day to an exercise program did not result in weight loss in overweight women.2
References

1. He Z-Q, Phone ZS. Body weight reductionin adolescents by a combination of measures including using L-carnitine. Acta NutrimentaSinica 1997;19.

2. VillaniRG, Gannon J, Self M, Rich PA. L-Carnitine supplementation combined with aerobictraining does not promote weight loss in moderately obese women. Int J SportNutrExerc Metab 2000;10:199-207.

Asthma
Dose: Refer to label instructionsIn a double-blind trial, supplementing with L-carnitine (1,050 mg each morning for six months) improved lung function and overall asthma control, compared with a placebo, in Egyptian children with asthma.1
References

1. Al-Biltagi M, Isa M, Bediwy AS, et al. L-Carnitine improves the asthma control in children with moderate persistent asthma. J Allergy (Cairo) 2012;2012:509730.

Sprains and Strains and Exercise-Related Muscle Injury
Dose: 3 grams per day

One controlled trial showed that people who supplement with 3 grams per day L-carnitine for three weeks before engaging in an exercise regimen are less likely to experience muscle soreness.1

References

1. Giamberardino MA, Dragani L, Valente R, et al. Effects of prolonged L-carnitine administration on delayed muscle pain and CK release after eccentric effort. Int J Sports Med 1996;17:320-4.

L-carnitine is made in the body from the amino acids lysine and methionine, and is needed to release energy from fat. It transports fatty acids into mitochondria, the powerhouses of cells. In infancy, and in situations of high energy needs, such as pregnancy and breast-feeding, the need for L-carnitine can exceed production by the body. Therefore, L-carnitine is considered a "conditionally essential" nutrient.1

Copyright 2014 Aisle7. All rights reserved. Aisle7.com

The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2015.

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Ratings and Reviews

REVIEW SNAPSHOT®

by PowerReviews
GNC Pro Performance® Liquid L-Carnitine
 
3.3

(based on 9 reviews)

67%

of respondents would recommend this to a friend.

Pros

  • Easy to take (6)
  • Good value (4)

Cons

    Best Uses

    • Daily use (6)

    Reviewed by 9 customers

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    Displaying reviews 1-9

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    3.0

    consume bottling agents at is frequently

    By dre500

    from gastonia nc 28052

    About Me Rarely Workout

    See all my reviews

    Pros

    • Easy To Take

    Cons

    • Doesn't Mix Well

    Best Uses

    • Daily Use

    Comments about GNC Pro Performance® Liquid L-Carnitine:

    drinking this formula as is has purities at best restoring engeries found for cosuming stock as the endurance to post work-out fuel; can use more of less of this formula.

    (3 of 5 customers found this review helpful)

     
    1.0

    Not for low carb lifestyle

    By carmenta50

    from Redondo Beach, CA

    See all my reviews

    Pros

      Cons

      • Sickenly Sweet
      • Tastes Bad

      Best Uses

        Comments about GNC Pro Performance® Liquid L-Carnitine:

        Unfortunately, did not notice the carb content because the label said no sugar. 12 gm carbs for 1000 mg of product! Since my doc suggested I take 1000 mg both morning and evening, that's 24 very unnecessary gm of carbs. Wanted a liquid, but may have to switch to capsules.

        (1 of 2 customers found this review helpful)

         
        5.0

        Tastes Great

        By rentfro

        from Riverside, Ca

        About Me Weekend Warrior

        See all my reviews

        Verified Buyer

        Pros

        • Easy To Take

        Cons

          Best Uses

          • Daily Use

          Comments about GNC Pro Performance® Liquid L-Carnitine:

          Good Stuff

          (4 of 5 customers found this review helpful)

           
          4.0

          Good Stuff

          By jjchavarro

          from Brentwood, New York

          About Me Competitive Athlete

          See all my reviews

          Verified Buyer

          Pros

          • Easy To Take

          Cons

            Best Uses

            • Daily Use

            Comments about GNC Pro Performance® Liquid L-Carnitine:

            I use it on empty stomach

            (2 of 5 customers found this review helpful)

             
            2.0

            Worked well tasted like cough medicine

            By pchuckie

            from New Jersey

            About Me Exercise Intolerence, Lactic Acidosis, Mitochondrial Disease

            See all my reviews

            Pros

            • Easy To Take
            • Good Value
            • Helps With Fatigue
            • Helps With Immune System

            Cons

            • Taste like cough medicine

            Best Uses

            • Carnitine Deficiency
            • Daily Use
            • Dietary Replacement

            Comments about GNC Pro Performance® Liquid L-Carnitine:

            I used this product because I have Mitochondrial Disease with Lactic Acidosis. In other words, I over create Lacatic Acid and my muscles fatigue out very quickly. This product helps stop the lactic acid build up and gives me energy. I take it first thing in the morning, if I take it in the evening it keeps me from sleeping. It works well but I couldn't get past the taste. I choose liquid over tablets because I already take too many prescription large pills and want something that would be easy to take. This one taste too much like cherry cough medicine; if they would fix the flavor and consistency I would try again.

            (7 of 7 customers found this review helpful)

             
            5.0

            Used it for years

            By hsuddleson

            from Washington, DC

            About Me Rarely Work Out

            See all my reviews

            Pros

            • Easy To Take
            • Good Value

            Cons

              Best Uses

              • Daily Use
              • Pre-workout

              Comments about GNC Pro Performance® Liquid L-Carnitine:

              This product works best half an hour before a workout, but can also be good as daily use. Liquid form means it's more easily absorbed.

              Bottom line, this is the one substance that carried fat across the cell wall to be burned as fuel. This stuff is safe into gram amounts so I take some every day, and more if I am going to work out. I highly recommed it.

              (12 of 18 customers found this review helpful)

               
              1.0

              Sodium benzoate?

              By zak_kam

              from Brunei.

              About Me Weekend Warrior

              See all my reviews

              Pros

              • Good Value

              Cons

              • Has Side Effects

              Best Uses

              • Pre-workout

              Comments about GNC Pro Performance® Liquid L-Carnitine:

              I wonder why GNC used sodium benzoate in the L-carnitine? it is such as shame that this evidence based and effective non-amino acid is being mixed with sodium benzoate. Beverages Industry has long ceased producing carbonated drink with added sodium benzoate due to the carcinogenic effect of benzene. Sodium benzoate can be converted into benzene in acidic condition as in citric acid.

              (6 of 6 customers found this review helpful)

               
              5.0

              Love It!

              By taylorbn2004

              from Las Vegas, NV

              About Me Competitive Athlete

              See all my reviews

              Pros

              • Easy To Take
              • Good Value
              • Tastes Fine

              Cons

                Best Uses

                • Daily Use

                Comments about GNC Pro Performance® Liquid L-Carnitine:

                I take this in conjunction with Muscle Ignition 4x and Mega Men Energy & Metabolism multivitamin. Works great. Keeps me energized throughout the day.

                Started taking these supplements a month ago along with working out 5x a week 1.5 hours each time. I have lost 12 lbs & almost 2% body fat. I can see myself taking these supplements for a long time.

                (3 of 15 customers found this review helpful)

                 
                4.0

                carnitine

                By soniascotti

                from Milan, Italy

                See all my reviews

                Comments about GNC Pro Performance® Liquid L-Carnitine:

                i use this product before sport activity

                Displaying reviews 1-9

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