Carnitine Supplement health benefit and side effects, helps improve energy and useful for heart tissue by Ray Sahelian, M.D.
Does this nutrient help with weight loss? What is the right daily dosage, is it 100 mg, 200, 250, 500, or 1000 mg
Research studies with propionyl l carnitine, and other forms such as tartrate and fumarate
Mind Power Rx - potent natural brain booster that works within hours to improve focus and alertness along with mental stamina

L-carnitine is a naturally occurring substance found in most cells of the body, particularly the brain, neural tissue, muscle, and heart. Carnitine, whose structure is similar to choline, is widely available in animal foods (meat, poultry, fish and dairy products), whereas plants have very small amounts. Most non-vegetarians consume about 100 to 300 mg of carnitine a day, and the body is able to synthesize this nutrient if dietary intake is inadequate. When ingested as a pill, carnitine is not able to cross the blood-brain barrier as well as its activated form acetyl-L-carnitine. Acetyl l carnitine has a more noticeable mental effect than carnitine. Acetyl l carnitine usually enhances mental clarity and focus, along with slight mood elevation. The effects of carnitine tend to be more physical than mental, in the sense that it provides enhanced physical energy whereas acetyl l carnitine provides more mental energy.
     Both acetyl l carnitine and carnitine are wonderful antioxidants, although the former may be more powerful. See acetylcarnitine for details. If you have an interest in eating less, consider Diet Rx.

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Subscribe to a FREE Supplement Research Update newsletter. Once or twice a month you will receive by email a review of several studies on various supplements and natural medicine topics, including l carnitine research and reviews of the latest thoughts about natural and integrative health and healing and ways to fight fatigue and have all day physical and mental energy.

Mind Power Rx with carnitine

Memory and Mood
Mental clarity
Concentration 
Alertness and Focus

Why buy all the individual herbs and nutrients separately -- at great expense -- when you can buy this excellent combination? The herbs in Mind Power Rx include: Ashwagandha, Bacopa, Fo-Ti, Ginkgo biloba,  Ginseng, Gotu kola, Mucuna pruriens, Reishi, and Rhodiola.  The nutrients and vitamins in Mind Power Rx include Acetyl-l carnitine, Carnitine, Carnosine, Choline, DMAE, Inositol, Methylcobalamin, Pantothenic acid, Trimethylglycine, Tyrosine, and Vinpocetine. 

What's the right dosage for l carnitine?
Since each person has a unique biochemistry, dosage recommendations vary. A carnitine dosage range of 50 to 500 mg daily works for most people. Take a day or two off each week. The effects of carnitine accumulate over time, therefore your dosage may need to be reduced or you may wish to take breaks more often. Much depends on whether you are taking other medications and supplements. If you are already taking natural products that increase energy, your required dosage of this nutrient would be less since taking too many energy enhancing natural pills can cause restlessness and insomnia.

Lcarnitine benefits - see the studies listed below
This supplement has potential as a treatment in several conditions, but more research is needed to determine the appropriate dosage and interactions with various other supplements and medications.
    
ADHD --Treatment with carnitine decreased attention problems and aggressive behavior in boys with ADHD.
Diabetes - Oral administration reduces oxidized LDL cholesterol levels in patients with type 2 diabetes.
Exercise -- Carnitine improves recovery after heavy exercise and may be of use in improving exercise capacity of people with peripheral arterial disease. Carnitine moderately improves the duration of exercise and time to recovery in patients with chronic stable angina.
Fatigue -- Carnitine may improve fatigue in certain conditions, including cancer patients receiving chemotherapy. Carnitine decreases the severity and type of fatigue induced by interferon-alpha in the treatment of patients with hepatitis C. Administration of carnitine to healthy elderly subjects results in a reduction of total fat mass, an increase of total muscle mass, and appears to exert a favorable effect on fatigue and serum lipids. Older individuals may benefit from the use of this nutrient to enhance energy levels and wellbeing.
Fertility -- Carnitine and acetyl carnitine therapy are effective in increasing fertility and sperm-semen quality. Also consider the herb maca from South America.
Heart Failure -- Those with heart failure may benefit from carnitine supplements.
Hyperthyroidism -- Carnitine is effective in both reversing and preventing symptoms of hyperthyroidism and has a beneficial effect on bone mineralization. Because hyperthyroidism depletes the body deposits of carnitine and since this supplement has little toxicity, teratogenicity, contraindications and few interactions with drugs, carnitine can be of clinical use.
Kidney dialysis -- Intravenous carnitine is an accepted pharmaceutical treatment for carnitine deficiency in end-stage renal disease in patients undergoing dialysis.
Liver cirrhosis -- Treatment of patients with liver cirrhosis with signs of liver insufficiency is complex and seldom satisfactory. Carnitine is involved in liver lipid metabolism and thus might be a potentially effective nutrient. One study shows L carnitine lowers serum ammonia concentration and improves lipid metabolism in patients with liver cirrhosis. Carnitine may also play a beneficial role in the treatment of mild or moderate hepatic encephalopathy, and perhaps liver cancer.
Sexual health -- Apparently l carnitine is helpful in sexual enhancement. Acetyl-l-carnitine is also helpful in this regard. There are many herbs that are much more potent, including tribulus terrestris, mucuna pruriens, maca, catuaba, yohimbe, and tongkat ali.
Thalassemia -- Lcarnitine may be an effective substance for improving the cardiac status of thalassemic patients.
Weight Loss -- The combination of l carnitine, choline, and caffeine has a mild effect on weight loss. It is not clear whether this nutrient, taken alone, has any significant effect on fat burning or loss of weight.

For diabetic patients
L-Carnitine supplementation reduces oxidized LDL cholesterol in patients with diabetes.
American Journal of Clinical Nutrition, January 2009.Mariano Malaguarnera, Marco Vacante, Teresio Avitabile, Marcella Malaguarnera, Lisa Cammalleri and Massimo Motta.
Patients with type 2 diabetes are under high oxidative stress, and levels of hyperglycemia correlate strongly with levels of LDL oxidation. Carnitine favorably modulates oxidative stress. This objective of this study was to evaluate the efficacy of L-carnitine on the reduction of oxidized LDL cholesterol in patients with type 2 diabetes. Eighty-one patients with diabetes were randomly assigned to 1 of 2 treatment groups for 3 mo. The 2 groups received either 2 grams once daily or placebo. At the end of the study period, the L-carnitine-treated patients showed significant improvements compared with the placebo group in the following markers: oxidized LDL levels decreased; LDL cholesterol decreased; triglycerides decreased; apolipoprotein A1 concentrations decreased; apolipoprotein B-100 concentrations decreased. Our study indicates that oral administration reduces oxidized LDL cholesterol levels in patients with type 2 diabetes.

Benefit for fatigue
L carnitine supplements may benefit certain patients with fatigue if there are no obvious causes for the fatigue, such iron deficiency anemia, a serious medical condition, etc.
   Even a hundred year old may benefit from carnitine supplements. Italian researchers at the University of Catania gave sixty-six centenarians 2 grams l carnitine daily for six months. At the end of the study period, the l carnitine treated centenarians showed significant improvements in total fat mass and total muscle mass. They were also less likely to have physical and mental fatigue. LDL-cholesterol levels fell among the individuals taking the supplement. L-carnitine takers gained 3.8 kilograms (8.4 pounds) of muscle mass, on average, and lost 1.8 kg (4 pounds) of fat mass. People given L-carnitine were also able to walk 4 meters  further during a 6-minute walking test after treatment than those given placebo.
   Comments: This study shows how much we still can learn about the benefits of supplements in the aged. My preference would be to use a lower amount of carnitine, such as 250 mg or 500 mg. Sometimes when high dosages of energy enhancing pills are taken for prolonged periods, they can accumulate and interfere with sleep.

L-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial
American Journal of Clinical Nutrition, Vol. 86, No. 6, 1738-1744, December 2007. Mariano Malaguarnera, Lisa Cammalleri, Maria Pia Gargante, Marco Vacante, Valentina Colonna and Massimo Motta. From the Department of Senescence, Urological, and Neurological Sciences, University of Catania, Catania, Italy
Sixty-six centenarians with onset of fatigue after even slight physical activity were recruited to the study. The 2 groups received either 2 grams l carnitine once daily or placebo. Efficacy measures included changes in total fat mass, total muscle mass, serum triacylglycerol, total cholesterol, HDL cholesterol, LDL cholesterol. The l carnitine treated centenarians, compared with the placebo group, showed significant improvements in total fat mass, total muscle mass, and plasma concentrations of total carnitine. Significant differences were also found in physical fatigue and mental fatigue. Our study indicates that oral administration of l carnitine produces a 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.

L carnitine administration in elderly subjects with rapid muscle fatigue: effect on body composition, lipid profile and fatigue.
Drugs Aging. 2003;20(10):761-7.
L carnitine is an important contributor to cellular energy metabolism. This study aims to evaluate the effects of carnitine supplementation on body composition, lipid profile and fatigue in elderly subjects with rapid muscle fatigue.  Eighty-four elderly subjects with onset of fatigue following slight physical activity were recruited to the study. One group received carnitine 2g twice daily and the other placebo. At the end of the study, compared with placebo, the carnitine-treated patients showed significant improvements in the following parameters: total fat mass, total muscle mass, total cholesterol, LDL-C, HDL-C, triglycerides, apoA1, and apoB. There was improvement in physical fatigue and mental fatigue. Administration of carnitine to healthy elderly subjects resulted in a reduction of total fat mass, an increase of total muscle mass, and appeared to exert a favourable effect on fatigue and serum lipids.

Heart health
I take L-Carnitine for my heart. Would the acetyl version be of more benefit or should I stick with the former?
   It is not possible to know in any individual person without knowing the full medical history and exam. There are many other natural option for heart health which are reviewed on the heart disease page.

Does carnitine help with weight loss?
L carnitine may be an effective supplement for weight loss by itself, but when combined with other nutrients it is even more effective.

The effect of l-carnitine on fat oxidation, protein turnover, and body composition in slightly overweight subjects.
Metabolism. 2004 Aug;53(8):1002-6.
We used a combined tracer technique with the stable isotopes (13)C and (15)N to gain further insight into the metabolic changes that accompany supplementation of l-carnitine. The aim of the present study was to investigate whether l-carnitine supplementation can influence fat oxidation, protein turnover, body composition, and weight development in slightly overweight subjects. Twelve volunteers received an individual regular diet either without or with l-carnitine supplementation of 3 grams a day for 10 days. Body fat mass, total body water, and lean body mass were calculated by using bioelectric impedance analysis. L-carnitine supplementation led to a significant increase in protein synthesis indicating that the increased dietary fat oxidation in slightly overweight subjects was not accompanied by protein catabolism.

Caffeine, carnitine and choline supplementation of rats decreases body fat and serum leptin concentration as does exercise.
J Nutr 2000 Feb;130(2):152-7
The effect of a combination of caffeine, carnitine and choline with or without exercise on changes in body weight, fat pad mass, serum leptin concentration and metabolic indices was determined in 20 male, 7-wk-old Sprague-Dawley rats. They were given free access to a nonpurified diet without or with caffeine, carnitine and choline at concentrations of 0.1, 5 and 11.5 g/kg diet, respectively. In a 2x2 factorial design, one-half of each dietary group was exercised, and the other half was sedentary. Food intake of the groups was not different, but the body weight was significantly reduced by exercise in both dietary groups. Fat pad weights and total lipids of epididymal, inguinal and perirenal regions were significantly reduced by the supplements as well as by exercise. Regardless of exercise, supplements significantly lowered triglycerides in serum but increased levels in skeletal muscle. Serum leptin concentrations were equally lowered by supplements and exercise. Serum leptin was correlated with body weight, fat pad weight  and serum glucose. We conclude that the indices of body fat loss due to dietary supplements with carnitine were similar to those due to mild exercise, and there were no interactive effects of the two variables.

Benefit for fertility and sperm health
Combined treatment with L-carnitine, a popular dietary supplement, and acetyl-carnitine, a related chemical, appears to improve sperm motility in men with fertility problems, according to a new study. In the study, 60 infertile men between the ages of 20 and 40 years were randomly selected to take a combination of L-carnitine and L-acetyl-carnitine or an inactive "placebo" for 6 months. In the medical journal Fertility and Sterility, researchers at the University of Rome led by Dr. Andrea Lenzi report that 2 months after the completion of therapy, men who took L-carnitine and acetyl carnitine had increases in sperm concentration, forward movement, and total movement. The most significant improvements in sperm motility, both forward and total, were observed in men who had the lowest levels of moving sperm when the study began. The researchers note that four spontaneous pregnancies were achieved during the study by men who had taken the combination therapy.

Placebo-controlled double-blind randomized trial on the use of L-carnitine, L-acetyl carnitine, or combined L-carnitine and L-acetyl carnitine in men with idiopathic asthenozoospermia.
Fertility & Sterility 2005 Sep;84(3):662-71. Andrology unit, Department of Internal Medicine, Polytechnic University of Marche, Italy.
We evaluated the effectiveness of L-carnitine or acetyl carnitine or combined carnitine and acetyl carnitine treatment in improving semen kinetic parameters. Sixty infertile men, ages 20 to 40 years, with the following baseline sperm selection criteria: concentration > 20 x 10(6)/mL, sperm forward motility < 50%, and normal sperm morphology > 30%. Patients underwent a double-blind therapy of carnitine 3 grams a day, acetyl carntine 3 grams a day, a combination of carnitine 2 g/d and acetyl carnitine 1 g/d, or placebo for a period of six months. Sperm cell motility increased in patients to whom acetyl carnitine was administered both alone or in combination with carnitine; combined carnitine + acetyl l carnitine therapy led to a significant improvement of straight progressive velocity. The administration of carnitine and acetyl carnitine is effective in increasing sperm kinetic features in patients affected by idiopathic asthenozoospemia and improves the total antioxidant status of the seminal fluid.

Liver health
L-carnitine inhibits hepatocarcinogenesis via protection of mitochondria.
Int J Cancer. 2004 Oct 21
Hepatocellular carcinoma is usually preceded by chronic inflammation. Recently, we reported that mitochondrial dysfunction plays an important role in hepatocarcinogenesis via the production of free radicals. Furthermore, we proved that L-carnitine effectively protects mitochondrial function in vivo. Therefore, we investigated whether long-term administration of L carnitine could prevent hepatitis and subsequent hepatocellular carcinoma in Long-Evans Cinnamon rats that are often analyzed as a model of hepatocarcinogenesis. The results indicated that oxidative stress elicited from abnormally accumulated copper increased the amount of free fatty acids, thereby inducing mitochondrial dysfunction, resulting in cell death and enhanced secondary generation of reactive oxygen species, which were significantly inhibited by carnitine treatment. Mitochondrial injury plays an essential role in the development of liver cancer and the clinical use of carnitine may have therapeutic potential in individuals with chronic hepatitis.

Thalassemia blood disorder
Effect of L-carnitine on the physical fitness of thalassemic patients.
Ann Hematol. 2007 January. El-Beshlawy A, El Accaoui R, Abd El-Sattar M, Gamal El-Deen MH, Youssry I, Shaheen N, Hamdy M, El-Ghamrawy M, Taher A. Department of Pediatrics, New Children Hospital, Cairo University, Cairo, Egypt.
Poor physical fitness is a common problem among patients with thalassemia. The main objective of this study is to assess the effect of the administration of oral L-carnitine on exercise tolerance and physical fitness in patients with thalassemia major. Thirty patients followed up at the New Cairo University Children Hospital were included in this study. Clinical, laboratory, and cardiopulmonary exercise testing were performed before and after 6 months of oral L-carnitine therapy (50 mg per kg per day). The oxygen consumption, cardiac output, and oxygen pulse at maximal exercise significantly increased after L-carnitine therapy. However, there was no significant change in minute ventilation and ventilatory equivalent of carbon dioxide. There was also significant increase in the blood transfusion intervals after L-carnitine administration. However, there was no significant change in hemoglobin concentration. L-Carnitine seems to be a safe and effective adjunctive therapeutic approach in thalassemic patients. It improves their cardiac performance and physical fitness. The younger the patients are, the higher is the degree of improvement in their exercise parameters.
   Comments: For long term use we suggest using a much lower dosage of 5 to 10 mg per kilogram body weight.

L carnitine side effects, safety, danger, caution, risks
It seems l carnitine is a relatively safe nutrient in doses ranging from 50 to 500 mg. Higher doses of carnitine may lead to excess energy, restlessness, perhaps insomnia. Long term side effects of high dose carnitine use are not fully known.

Carnitine and acetyl l carnitine as anti-aging supplements?
In addition to producing energy, these two nutrients remove toxic accumulations of fatty acids from mitochondria, keeping these organelles healthy and functioning at their best. Energy production in mitochondria is not a perfect process and toxic metabolites do accumulate. Accumulation of these toxic metabolites and the resulting oxidative damage is likely to contribute to aging of cells. A waste substance called lipofuscin accumulates in cells as we age and perhaps adequate acetyl-l carnitine intake can help minimize this accumulation. A study in rats providing acetyl-l carnitine from youth showed this nutrient to decrease lipofuscin levels in their brain as they got old. Therefore, it is theoretically possible that supplementation with carnitine or acetyl-l-carnitine can slow the aging process.

Deficiency
Carnitine is comprised of two amino acids, lysne and methionine. Its role is to transport long-chain fatty acids across the cell's inner mitochrondial membrane. Mitochrondia use fatty acids and glucose to produce energy. Secondary carnitine deficiency is a rare metabolic disorder usually diagnosed at birth. However, primary carnitine deficiency, which is due to decreased synthesis of carnitine in the body or altered transport of carnitine across the cellular membrane, can occur in people of all ages. Carnitine levels decrease with age.

Metabolism
Carnitine, the L-beta-hydroxy-gamma-N-trimethylaminobutyric acid, is synthesized primarily in the liver and kidneys from lysine and methionine. Carnitine covers an important role in lipid metabolism, acting as an obligatory cofactor for beta-oxidation of fatty acids by facilitating the transport of long-chain fatty acids across the mitochondrial membrane as acylcarnitine esters. Furthermore, since carnitine behaves as a shuttle for acetyl groups from inside to outside the mitochondrial membrane, it covers a key role in glucose metabolism and assists in fuel-sensing. A reduction of the fatty acid transport inside the mitochondria results in the cytosolic accumulation of triglycerides, which is implicated in the pathogenesis of insulin resistance.

Various forms of carnitine supplements are available:
Raw material suppliers, such as Sigma Tau, have a wide variety of carnitine products, including:
L-Carnitine Fumarate
L-Carnitine Base USP, FCC, EP
L-Carnitine Hydrochloride
L-Carnitine Creatine Dihydrogen Phosphate
L-Carnitine Hydrogen Fumarate Creatinate
Lysine L-Carnitine Fumarate Hydrochloride
Glycine Propionyl L-Carnitine Hydrochloride
   There has not been enough research with each of these forms to determine which is best for long term human consumption.

Free and total carnitine concentrations in pig plasma after oral ingestion of various L carnitine compounds.
Int J Vitamin Nutrition Research. 2005 Jan;75(1):3-9.
This study was undertaken to investigate the bioavailability of various L carnitine esters (acetyl L carnitine and lauroyl L carnitine) and salts (L carnitine L tartrate, L carnitine fumarate, L carnitine magnesium citrate) relative to base of free L carnitine. Six groups of five or six piglets each were administered orally a single dose of 40 mg L carnitine equivalents/kg body weight of each of those L carnitine compounds. AUC values, calculated for the time interval between 0 and 32 hours, for both free and total carnitine were similar for base of free L carnitine and the three L carnitine salts (L carnitine L tartrate, L carnitine fumarate, L carnitine magnesium citrate) while those of the two esters (acetyl L carnitine, lauroyl L carnitine) were lower. Administration of Lcarnitine L tartrate yielded a higher plasma free carnitine AUC value for the time interval between 0 and 3.5 hours than administration of the other compounds. The data of this study suggest that L carnitine salts have a similar bioavailability to that of free L carnitine while L carnitine esters have a lower one. The study also suggests that L carnitine L tartrate is absorbed faster than the other L carnitine compounds.

Propionyl l carnitine research studies
Evaluation of the efficacy of propionyl-L-carnitine versus pulsed muscular compressions in diabetic and non-diabetic patients affected by obliterating arteriopathy Leriche stage II.
Int Angiol. 2008 June. Riccioni C, Sarcinella R, Palermo G, Izzo A, Liguori M, Koverech A, Messano M, Virmani A. Complex Unit of Angiology, Nuovo Regina Margherita Hospital, Rome, Italy.
The effectiveness of propionyl L carnitine (PLC) monotherapy regimen alone or in association with pulsed muscular compression was compared to the physical therapy by itself against obliterant arteriopathy Leriche Fontaine stage II. Propionyl L carnitine is involved in cellular metabolism and is transformed into two active substances, free L-carnitine and propionyl-coenzyme A in the mitochondria, which take part in fatty acid transfer and in the citric acid cycle, respectively. Forty-two patients with arterial disease were selected (22 males and 20 females; mean age: 62+/-8 years; 21 type 2 diabetic [DB] and 21 non-DB [NDB]). Patients were randomized in three groups, each of them composed by 14 patients (7 DB and 7 NDB): the first group was submitted to infusional propionyl L carnitine therapy at a dosage of 4 fl (total: 1,200 mg PLC) in 250 cc of physiological solution for 5 days a week for 4 weeks; the second group was treated with PLC in association with pulsed muscular compression therapy by Vascupump (5 sessions a week for 4 weeks); the third group was submitted only to Vascupump. The efficacy of both propionyl L carnitine and Vascupump in the treatment of the peripheral vasculopathies was confirmed. From a subjective point of view, patients referred benefits both in clinical terms, i.e. increased walking distance and of decreased intensity of the calf pain from the quality of life questionnaire (21.5 to 10.7). The instrumental parameters showed a trend towards normality. Combined pharmaco- and physical therapy was most efficient treatment regime and best results were seen in NDB compared to the DB patients.

Levo-propionyl-carnitine improves the effectiveness of supervised physical training on the absolute claudication distance in patients with intermittent claudication.
Angiology. 2008 Feb-Mar; Andreozzi GM, Leone A, Laudani R, Martin R, Deinit G, Cataldi V. Angiology Care Unit of University Hospital of Padua, Italy.
The mechanisms by which supervised physical training improves walking ability in patients with intermittent claudication (IC) are microcirculatory, rheological, and metabolic. The main mechanism of levo-propionylcarnitine (LPC) is metabolic; it increases the walking ability in claudicants, providing an additional energy to the ischemic muscle by an anaplerotic activity. Therefore, the current study was carried out to ascertain whether the combined treatment has a synergistic effect. The results confirm the effectiveness of supervised physical training in patients with IC, and we recommend the use of LPC during the exercise training program, at least in patients with severe claudication. Finally, underlining the similar mechanisms of physical training and LPC treatment, the study suggests that a cycle of LPC infusions could be advised in patients with severe claudication who cannot be included, for various reasons, in an exercise rehabilitation program.

Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance.
Int J Sport Nutr Exerc Metab. 2008 Feb; Smith WA, Fry AC, Tschume LC, Bloomer RJ. Dept. of Health and Sport Sciences, University of Memphis, Memphis, TN 38152, USA.
The purpose of this study was to evaluate the effect of glycine propionyl-L-carnitine (GPLC) supplementation and endurance training for 8 wk on aerobic- and anaerobic-exercise performance in healthy men and women (age 18-44 yr). Participants were randomly assigned to 1 of 3 groups: placebo (n=9), 1 g/d GPLC (n=11), or 3 g/d GPLC (n=12), in a double-blind fashion. Muscle carnitine (vastus lateralis), VO(2peak), exercise time to fatigue, anaerobic threshold, anaerobic power, and total work were measured at baseline and after an 8-wk aerobic-training program. There were no statistical differences (p> .05) between or within the 3 groups for any performance-related variable or muscle carnitine concentrations after 8 wk of supplementation and training. These results suggest that up to 3 g/d GPLC for 8 wk in conjunction with aerobic-exercise training is ineffective for increasing muscle carnitine content and has no significant effects on aerobic- or anaerobic-exercise performance.

Carnitine research study
Comparison of the effects of L-carnitine and acetyl-L carnitine on carnitine levels, ambulatory activity, and oxidative stress biomarkers in the brain of old rats.
Ann N Y Acad Sci. 2004 Nov;1033:117-31.
L-carnitine and acetyl-L carnitine are both used to improve mitochondrial function. Although it has been argued that acetyl-L carnitine is better than l-carnitine in absorption and activity, there has been no experiment to compare the two compounds at the same dose. In the present experiment, the effects of acetyl-L carnitine and L carnitine on the levels of free, acyl, and total L-carnitine in plasma and brain, rat ambulatory activity, and biomarkers of oxidative stress are investigated. Aged rats were given acetyl-L carnitine or L-carnitine at 0.15% in drinking water for 4 weeks. L-carnitine and acetyl-L carnitine were similar in elevating carnitine levels in plasma and brain. Both increased ambulatory activity similarly. However, acetyl-L carnitine decreased the lipid peroxidation in the old rat brain, while L-carnitine did not. Acetyl-L carnitine decreased the extent of oxidized nucleotides while L-carnitine did not. In conclusion, acetyl-L carnitine and L-carnitine were similar in increasing ambulatory activity in old rats and elevating carnitine levels in blood and brain. However, acetyl-L carnitine was effective, unlike L-carnitine, in decreasing oxidative damage in old rat brain. These data suggest that acetyl-L carnitine may be a better dietary supplement than L-carnitine.

Carnitine article written for Today's Health and Wellness magazine in 2007
Do you sometimes find yourself low on energy and wish you had an alternative to coffee or sodas for a pick me up? You're in luck. There are dozens of effective herbs and nutrients that can help you have more energy so you can go ahead and complete all your obligations and responsibilites for the day. In this article I will mention two important nutrients, carnitine and pantothenic acid. Pantothenic acid happens to be one of the B vitamins.

L-Carnitine, or simply known as carnitine, is a naturally occurring substance found in the body, particularly in brain, muscles, and heart. If you eat meat producs, you are likely to consume carnitine in adequate amounts since it is widely available in animal foods (meat, poultry, fish and dairy products), whereas plants have very small amounts. Most non-vegetarians consume about 100 to 300 mg of carnitine a day, and the body is able to make this nutrient if dietary intake is inadequate. Another nutrient related to carnitine is acetylcarnitine. Acetylcarnitine has more of an influence on mental function and mind energy whereas carnitine has more of an influence on physical energy. Both carnitine and acetylcarnitine are sold as supplements.

Benefits
If you have a normal diet, you are likely to get adequate amounts of carnitine, yet there are times when taking a carnitine supplement could be helpful. Several studies show carnitine, when given as a daily supplement, improves recovery after heavy exercise. In other words, people experience less fatigue. Carnitine also mproves the exercise capacity of people with peripheral arterial disease. Peripheral artery disease is a condition where the arteries that carry blood to the legs get clogged up and cause pain with walking after a short distance.
And that's not all. Carnitine fights fatigue in other medical conditions. Cancer patients receiving chemotherapy feel less tired when supplemented with carnitine. There's even talk that carnitine may be helpful in weight control and maintaining healthy cholesterol and triglyceride levels. In one trial, when carnitine was given to healthy elderly subjects, the results showed a reduction in total fat mass, an increase in total muscle mass, and a lowering of serum lipids.

Side effects
It seems carnitine is a relatively safe nutrient when the dosages are kept in the range of 100 to 500 mg a day. Higher doses of carnitine may lead to excess energy, restlessness, and perhaps insomnia.

Availability
Carnitine is sold by itself as a single nutrient in a bottle. It can be found in vitamin stores, on the internet, and many pharmacies or drug store chains. A number of natural products promoted for improving energy may contain carnitine along with other vitamins and herbs.

What's the right dosage for l carnitine?
Since each person has a unique biochemistry, dosage recommendations vary. A range of 50 to 250 mg daily or 500 mg a few days a week works for most people. As with many supplements, I recommending taking breaks from use. For instance, you can take off one or two days a week, and a week off per month. A carnitine supplement is particularly helpful for vegetarians since it is found in only small amounts in vegetables, fruits, and legumes.

L Carnitine supplement emails
I get the most wonderful 'feel good' and energy when I take SAM-e 100mg and 150 mg of L-carnitine.

Q. I am a 48 yr. female registered nurse from New Zealand. I have been taking L- Carnitine 300mg for 7 days to assist in weight loss after doing on-line research. Most of my 30 yr career in nursing has been as an operating theatre nurse because of this I suffer from plantar fascitis, first in my left foot resulting in a bony spur then in my right foot - no bony spur. This has been very painful, I have received many forms of treatment from orthopaedic surgeon i.e.: steroid injection to podiatrist etc. It has been very interesting to note that from Day 4 of taking L- carnitine that the usual level of daily pain has lessened considerably to zero even. Has the fascitis finally "burnt out" or has the L-Carnitine contributed in some way? I have other colleagues who suffer this horrendous pain and I would like to share this phenomenon with them.
     A. This is the first we have heard of this potential effect regarding L Carnitine and plantar fasciitis. It is difficult to say whether l carnitine was helpful or it was coincidence, we won't know until a few other people try it to see if they get the same response.

I have had on-going heavy duty depression since I was 18 yrs old. I don't have those ups and downs that I've heard so much about. Just an ongoing depression at different levels of "heaviness" throughout the day, day after day. At its heaviest point it's like my mind and body wants to shut off to the outside world. Vast majority of the time it's like my mind and body simply cannot produce energy. Here's the regimen I'm following that helps: In the mornings I'm taking 500 mg of Acetyl L-Carnitine with 2 cups of warm tea and 500 mg of l-carnitine l-tartrate along with 5-HTP 50 mg in the evening. It sure seems that I have nutritional needs that ought to be met daily.