Supplement Facts
Serving Size: 1 Capsule
Amount Per Serving
%DV
L-Carnitine (as L-Carnitine Tartrate)
500 mg
†
The product is found useful for the following medical conditions
Leg Cramps details
SCIENTIFIC SCORE
Moderately Effective
Based on 3 Researches
8
USERS' SCORE
Good
Based on 2 Reviews
8.7
9
We observed the impact of L-carnitine on leg cramps in a 69-year-old Japanese woman who experienced painful nocturnal leg cramps. This occurred after she had been on cefcapene-pivoxil, a pivalate-containing antibiotic, for six months.
Investigations revealed decreased levels of serum-free carnitine and acylcarnitine in her body, leading to a diagnosis of carnitine deficiency. We learned that this deficiency was likely caused by her long-term use of the antibiotic, which can interfere with carnitine absorption.
After starting oral L-carnitine treatment, we noted marked improvement in her symptoms, suggesting that L-carnitine could play a beneficial role in alleviating leg cramps associated with carnitine deficiency. This case serves as a reminder to consider carnitine levels in patients experiencing leg cramps, particularly those on pivalate-containing antibiotics.
Investigations revealed decreased levels of serum-free carnitine and acylcarnitine in her body, leading to a diagnosis of carnitine deficiency. We learned that this deficiency was likely caused by her long-term use of the antibiotic, which can interfere with carnitine absorption.
After starting oral L-carnitine treatment, we noted marked improvement in her symptoms, suggesting that L-carnitine could play a beneficial role in alleviating leg cramps associated with carnitine deficiency. This case serves as a reminder to consider carnitine levels in patients experiencing leg cramps, particularly those on pivalate-containing antibiotics.
10
Takes away cramps
Most Useful Review
28 people found this helpful
L-carnitine is a Godsend! It is available at a much better price than at my pharmacy. This excellent product is one of the few over-the-counter drugs that works better than prescription ones. It completely eliminated all back and leg cramps that I had suffered with for years, as my doctor recommended taking 1 tablet twice a day.
Updated: Apr 2025
Bone Pain details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 3 Reviews
8.5
9
Shoulder pain relief
Most Useful Review
3 people found this helpful
I have been taking Jarrow Formulas L-Carnitine Fumarate 500 alongside Alpha Lipoic Sustain. Although I can't definitively say it assists with muscle building, I have noticed that my shoulder pain has disappeared when using Alpha Lipoic.
Updated: Apr 2025
Cardiovascular Disease details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 2 Reviews
8.5
9
Holistic approach works
Most Useful Review
2 people found this helpful
My Cavalier King Charles Spaniels were diagnosed with early heart disease at a young age. Instead of immediately starting medication, I opted for a holistic approach with supplements recommended by my specialty vet, specifically the Jarrow brand. I administer it twice daily by opening the capsule and mixing it with their food, which they accept easily. At their recheck, both dogs showed improvement with no other changes aside from the addition of these supplements. I am extremely pleased with the outcome!
Updated: Apr 2025
Hyperthyroidism details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 3 Reviews
8.5
9
Healthy cat support
Most Useful Review
12 people found this helpful
These liquid capsules have helped my hyperthyroid cat tremendously. Previously, using powder was ineffective, but each capsule contains the correct dosage of 500mg. In just under a month, she has gained weight and become more active. While l-carnitine is not for those with hypothyroidism, it is a godsend for hyperthyroid conditions.
Updated: Mar 2026
Sleep Apnea details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 2 Reviews
8.5
9
Better sleep quality
Most Useful Review
6 people found this helpful
I sweat a lot and have been sleeping well! It's been a little over a week since I started losing weight. When I exercise, I sweat profusely. I used to experience shallow sleep and felt tired all the time, but now I sleep well and feel more comfortable upon waking. However, I do feel quite hungry. If you incorporate this into your routine, it will enhance your energy for more exercise.
Updated: Apr 2025
Weight Loss details
SCIENTIFIC SCORE
Questionable
Based on 13 Researches
6.9
USERS' SCORE
Good
Based on 10 Reviews
8.5
9
L-Carnitine supports weight loss in PCOS
In a well-designed study involving 60 overweight women with polycystic ovary syndrome (PCOS), we looked at the impact of 250 mg oral carnitine supplements over 12 weeks. Those taking carnitine lost an average of 2.7 kg and saw reductions in body mass index, waist, and hip circumferences.
Improvements also included better blood sugar control and lower insulin levels, indicating potential metabolic benefits. However, it’s important to note that carnitine did not influence lipid profiles or free testosterone levels. Overall, while it helped with weight and glucose management, results suggest it may have limitations.
Improvements also included better blood sugar control and lower insulin levels, indicating potential metabolic benefits. However, it’s important to note that carnitine did not influence lipid profiles or free testosterone levels. Overall, while it helped with weight and glucose management, results suggest it may have limitations.
9
Increased energy
Most Useful Review
23 people found this helpful
This works! I put my wife on this for energy and weight loss. She has noticed a significant increase in energy and has lost 5 lbs in 2 weeks without any exercise, which is impressive for her as she doesn't lose weight easily. My daughter, who is 18, was very fatigued with a racing heart several times daily. Since using this product, she has regained much more energy and her episodes of lowered heart rate have greatly reduced. P.S. Don't take it late at night as it may keep you awake.
Updated: Apr 2025
Brain Tumor details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8.4
9
Daily energy boost
Most Useful Review
Great quality! I take it daily as a brain and energy booster in the morning. I have no complaints so far.
Updated: Mar 2026
Heart Disease details
SCIENTIFIC SCORE
Moderately Effective
Based on 4 Researches
8.3
USERS' SCORE
Good
Based on 5 Reviews
8.4
9
We looked into how L-carnitine might help children facing myocardial injury during open-heart surgery. In our study involving 60 children with congenital heart disease, we split participants into two groups: one received L-carnitine before surgery, while the other got a placebo.
The findings were promising; the L-carnitine group showed lower levels of harmful markers indicating heart damage after surgery and better heart function compared to the placebo group. Overall, we found that L-carnitine may protect the heart and improve recovery in these young patients.
The findings were promising; the L-carnitine group showed lower levels of harmful markers indicating heart damage after surgery and better heart function compared to the placebo group. Overall, we found that L-carnitine may protect the heart and improve recovery in these young patients.
7.5
Helps heart issues
Most Useful Review
7 people found this helpful
Dr Sinatra recommends this product as the best form of carnitine for Myalgic Encephalomyelitis, and it has notably benefitted my heart problems. My ability to remain upright improved drastically from just 10 minutes to about 20. Additionally, combining it with ubiquinol has given me further strength. Dr Sinatra calls these two, along with ribose and magnesium, the 'awesome foursome' for cardiac health.
Updated: Mar 2026
Chronic Fatigue Syndrome details
SCIENTIFIC SCORE
Possibly Effective
Based on 8 Researches
7.8
USERS' SCORE
Good
Based on 5 Reviews
8.2
9
We investigated the effects of acetyl L-carnitine (ALC) on elderly patients experiencing chronic fatigue. In our study of 96 participants aged 70 and above, we found that ALC significantly reduced both physical and mental fatigue.
After treatment, improvements were noted in functional abilities and cognitive performance, with patients experiencing less muscle pain and fewer sleep disorders. Overall, our findings indicate that ALC can be an effective option for alleviating fatigue and enhancing quality of life in older individuals.
After treatment, improvements were noted in functional abilities and cognitive performance, with patients experiencing less muscle pain and fewer sleep disorders. Overall, our findings indicate that ALC can be an effective option for alleviating fatigue and enhancing quality of life in older individuals.
8
Enhanced energy levels
Most Useful Review
My experience with L-Carnitine has been positive. I've noticed a clear improvement in my energy levels and focus, particularly after long workdays. Since including L-Carnitine in my routine, I've felt more energised and have improved my endurance during workouts. I can push myself harder without feeling as fatigued. Overall, I am very satisfied with its effects on my health regimen.
Updated: Mar 2026
Heart Attack details
SCIENTIFIC SCORE
Moderately Effective
Based on 15 Researches
8.2
USERS' SCORE
Good
Based on 10 Reviews
8.1
9
We examined the effects of L-carnitine versus a placebo in patients who experienced acute heart attacks. Through a comprehensive review of 13 controlled trials involving over 3,600 participants, we found that L-carnitine led to notable benefits.
Specifically, it was linked to a 27% drop in overall death rates, a striking 65% reduction in life-threatening irregular heartbeats, and a 40% decrease in chest pain episodes.
However, it did not show significant improvements in heart failure or reinfarction rates. Our findings suggest that further large-scale studies should explore this promising, cost-effective treatment.
Specifically, it was linked to a 27% drop in overall death rates, a striking 65% reduction in life-threatening irregular heartbeats, and a 40% decrease in chest pain episodes.
However, it did not show significant improvements in heart failure or reinfarction rates. Our findings suggest that further large-scale studies should explore this promising, cost-effective treatment.
7.5
Great for heart problems
Most Useful Review
39 people found this helpful
This product is excellent for cardiac health and is regarded as the best form of carnitine by Dr Sinatra. It is particularly beneficial for my severe Myalgic Encephalomyelitis, helping me manage my heart issues effectively.
Updated: Apr 2025
Autoimmune Disorder details
SCIENTIFIC SCORE
Moderately Effective
Based on 9 Researches
8.2
USERS' SCORE
Moderately Good
Based on 3 Reviews
7.9
9
We explored the relationship between circulating L-carnitine levels and the risk of neuromyelitis optica spectrum disorders (NMOSD) using data from genetic studies.
Our findings indicate that higher levels of L-carnitine may protect against NMOSD, specifically in patients who are negative for aquaporin-4 antibodies. However, there's no causal effect on the seropositive type of NMOSD.
This suggests that while L-carnitine could be a potential biomarker and therapeutic target, its effectiveness may vary depending on the patient subtype.
Our findings indicate that higher levels of L-carnitine may protect against NMOSD, specifically in patients who are negative for aquaporin-4 antibodies. However, there's no causal effect on the seropositive type of NMOSD.
This suggests that while L-carnitine could be a potential biomarker and therapeutic target, its effectiveness may vary depending on the patient subtype.
7.5
Improved spermogram
Most Useful Review
3 people found this helpful
Fine! I ordered this for my husband in hopes of improving his spermogram activity. After four months, there have been improvements in the analyses. Excellent preparation!
Updated: Mar 2026
Pelvic Pain details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Moderately Good
Based on 3 Reviews
7.4
9
Shoulder pain resolved
Most Useful Review
3 people found this helpful
I'm taking Jarrow Formulas L-Carnitine Fumarate 500 together with Alpha Lipoic Sustain. While I'm uncertain about its effects on muscle building, I did notice that my shoulder pain has vanished when using Alpha Lipoic.
Updated: Apr 2025
Hypothyroidism details
SCIENTIFIC SCORE
Likely Ineffective
Based on 1 Research
4
USERS' SCORE
Moderately Good
Based on 2 Reviews
7.3
4
We conducted a systematic search of studies examining the effectiveness of various interventions for patients with persistent symptoms of hypothyroidism, particularly focusing on the use of L-carnitine. Although we found evidence related to several treatments, including ginger and surgery, the role of L-carnitine remains unclear due to its inclusion in a group of multiple interventions.
Specifically, L-carnitine was assessed in a clinical trial where it was compared to a placebo. However, the findings on its effectiveness were inconsistent when it came to improving symptoms related to hypothyroidism. Many of the studies we reviewed had limitations that included potential bias and variability in results, making it challenging to draw definitive conclusions about L-carnitine's impact on fatigue and quality of life in these patients.
Overall, there is no strong evidence suggesting that L-carnitine provides significant benefits for those suffering from persistent hypothyroidism symptoms. While some interventions showed promise, L-carnitine does not seem to be a game-changer in this context.
Specifically, L-carnitine was assessed in a clinical trial where it was compared to a placebo. However, the findings on its effectiveness were inconsistent when it came to improving symptoms related to hypothyroidism. Many of the studies we reviewed had limitations that included potential bias and variability in results, making it challenging to draw definitive conclusions about L-carnitine's impact on fatigue and quality of life in these patients.
Overall, there is no strong evidence suggesting that L-carnitine provides significant benefits for those suffering from persistent hypothyroidism symptoms. While some interventions showed promise, L-carnitine does not seem to be a game-changer in this context.
0
Interferes with treatment
Most Useful Review
3 people found this helpful
It's best to consult your doctor before taking any supplement. With my family history of heart issues, I try to be cautious about my diet and exercise. Unfortunately, this supplement interfered with my hypothyroidism. Despite my doctor’s advice to take it at night, I had to stop immediately. Research showed L-Carnitine prevents cells from absorbing thyroid hormones, exacerbating hypothyroidism symptoms, including heart palpitations and weight gain. Jarrow should include this information on their label to warn users.
Updated: Apr 2025
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