Acetyl-L-Carnitine Research
41 peer-reviewed studies · Evidence score: 9/10
Safety and efficacy of antioxidant therapy in children and adolescents with attention deficit hyperactivity disorder: A systematic review and network meta-analysis
Zhou P et al. • PloS one (2024)
The rankings of safety and efficacy of the 12 antioxidants vary.
- The rankings of safety and efficacy of the 12 antioxidants vary.
- Due to the low methodological quality of the included studies, the probability ranking cannot fully explain the clinical efficacy, and the results need to be interpreted with caution.
- More high-quality studies are still needed to verify our findings.
Nutraceutical interventions for erectile dysfunction: a systematic review and network meta-analysis
Barbonetti A et al. • The journal of sexual medicine (2024)
Against a background of general ineffectiveness of most nutraceutical interventions, L-Arginine and the mix PLC + ALC appeared to be of some usefulness in improving erectile function, especially in combination with PDE5i in organic ED.
- In patients with organic ED, the efficacy of Sildenafil and Tadalafil was significantly improved by PLC + ALC and L-Arginine, respectively.
- Against a background of general ineffectiveness of most nutraceutical interventions, L-Arginine and the mix PLC + ALC appeared to be of some usefulness in improving erectile function, especially in combination with PDE5i in organic ED.
- Further research warranted to confirm findings
The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomized Controlled Trials
Li KP et al. • Frontiers in endocrinology (2022)
l-Carnitine was ranked first in sperm motility and sperm morphology. ω-3 fatty acid was ranked first in sperm concentration.
- l-Carnitine was ranked first in sperm motility and sperm morphology. ω-3 fatty acid was ranked first in sperm concentration.
- Coenzyme-Q10 had better effective treatment on sperm motility and concentration.
- Furthermore, high-quality RCTs with adequate sample sizes should be conducted to compare the outcomes of different antioxidants.
Drug treatment for spinal muscular atrophy types II and III
Wadman RI et al. • The Cochrane database of systematic reviews (2020)
Nusinersen improves motor function in SMA type II, based on moderate-certainty evidence.
- Nusinersen improves motor function in SMA type II, based on moderate-certainty evidence.
- One trial of TRH did not measure motor function.
- Further research warranted to confirm findings
Acetyl-L-carnitine for the treatment of diabetic peripheral neuropathy
Rolim LC et al. • The Cochrane database of systematic reviews (2019)
We are very uncertain whether ALC causes a reduction in pain after 6 to 12 months' treatment in people with DPN, when compared with placebo, as the evidence is sparse and of low certainty.
- The risk of bias was high in both trials of different ALC doses and low in the other two trials.No included trial measured the proportion of participants with at least moderate (30%) or substantial (50%) pain relief.
- ALC reduced pain more than placebo, measured on a 0- to 100-mm VAS (MD -9.16, 95% CI -16.76 to -1.57; three studies; 540 participants; P = 0.02; I² = 56%; random-effects; very low-certainty evidence; a higher score indicating more pain).
- The overall certainty of adverse event evidence for the comparison of ALC versus placebo was low.The study comparing ALC with methylcobalamin reported that 34/117 participants (29.1%) experienced adverse events in the ALC group versus 33/115 (28.7%) in the methylcobalamin group (P = 0.95).
Impact of Dietary Supplements on Clinical Outcomes and Quality of Life in Patients with Breast Cancer: A Systematic Review
Scafuri L et al. • Nutrients (2025)
However, the evidence is mixed across supplement types, and further research is needed to determine the most effective and safe approaches.
- Curcumin studies presented mixed results.
- Silymarin showed potential for hepatoprotective effects.
- Conclusions: These findings highlight the potential of specific dietary supplements to improve various aspects of breast cancer care.
Effects of Carnitine and Coenzyme Q10 on Sperm Quality and Pregnancy Rates in Men with Unexplained Infertility: A Systematic Review and Network Meta-Analysis
Niu C et al. • Reproductive sciences (Thousand Oaks, Calif.) (2025)
CoQ10 was the most effective intervention measure for improving sperm concentration, and L-carnitine was regarded as the best treatment method for enhancing sperm motility.
- L-carnitine, coenzyme Q10 and L-carnitine + acetyl-L-carnitine significantly improved sperm quality parameters compared with placebo.
- CoQ10 induced the highest increase in sperm concentration (SMD 2.98 [95% CI: 1.13 to 7.87]).
- Furthermore, L-Carnitine has the greatest improvement effect on progressive sperm motility (SMD 4.19 [95% CI: 1.60 to 10.95]).
Differential Metabolites in Osteoarthritis: A Systematic Review and Meta-Analysis
Liao Z et al. • Nutrients (2023)
This meta-analysis examined the effects of Acetyl-L-Carnitine.
- In the 13 studies, 132 kinds of small molecule differential metabolites were extracted, 58 increased, 57 decreased and 17 had direction conflicts.
- Among them, 37 metabolites appeared more than twice.
- Further research warranted to confirm findings
Acetyl-L-carnitine in the treatment of peripheral neuropathic pain: a systematic review and meta-analysis of randomized controlled trials
Li S et al. • PloS one (2015)
The current evidence suggests that ALC has a moderate effect in reducing pain measured on VAS in PNP patients with acceptable safety.
- Compared with placebo, ALC significantly reduced VAS scores of PNP patients (MD of VAS, 1.20; 95% CI, 0.68-1.72, P <0.00001).
- The current evidence suggests that ALC has a moderate effect in reducing pain measured on VAS in PNP patients with acceptable safety.
- Larger trials with longer follow-up, however, are warranted to establish the effects.
Oral acetyl-L-carnitine treatment in hepatic encephalopathy: view of evidence-based medicine
Jiang Q et al. • Annals of hepatology (2013)
Acetyl-L-carnitine is promising as an effective and tolerable treatment for hepatic encephalopathy that associated with improved serum ammonia levels and the number connection test.
- Acetyl-L-carnitine was effective to improve serum ammonia level (weighted mean difference 25.90, 95% confidence intervals 20.89 to 30.91, P < 0.05) and the number connection test completion time (weighted mean difference 16.62, 95% confidence intervals 9.88 to 23.36, P < 0.05).
- Acetyl-L-carnitine is promising as an effective and tolerable treatment for hepatic encephalopathy that associated with improved serum ammonia levels and the number connection test.
- Further research warranted to confirm findings
Pharmacological Treatment of Chemotherapy-Induced Neuropathy: A Systematic Review of Randomized Clinical Trials
Jesus Palma AC et al. • Pain management nursing : official journal of the American Society of Pain Management Nurses (2025)
Duloxetine is an effective and well-tolerated option, while pregabalin shows promising results but requires further investigation.
- Investigated medications exhibited varied outcomes, with some showing significant benefits in reducing neuropathic pain while others did not demonstrate statistically significant efficacy.
- Duloxetine is an effective and well-tolerated option, while pregabalin shows promising results but requires further investigation.
- Other agents, such as venlafaxine and tapentadol, lack strong supporting evidence.
Triggers for acute mood episodes in bipolar disorder: A systematic review
Rodrigues Cordeiro C et al. • Journal of psychiatric research (2023)
This is the first systematic review about triggers/precipitants of relapse in BD.
- This is the first systematic review about triggers/precipitants of relapse in BD.
- Despite the importance of identification and management of potential triggers for BD decompensation, there is a lack of large observational studies addressing this topic, with most of the included studies being case reports/case series.
- Notwithstanding these limitations, antidepressant use is the trigger with the strongest evidence for manic relapse.
Acetyl-L-carnitine for depression: A systematic review
Veronese N et al. • Psychosomatic Medicine (2018)
ALCAR significantly reduced depressive symptoms comparable to antidepressants.
- Reduced depressive symptoms
- Comparable to standard antidepressants
- Fewer side effects
Dietary supplements and fatigue in patients with breast cancer: a systematic review
Pereira PTVT et al. • Breast cancer research and treatment (2018)
Dietary supplements or diet patterns are seldom used to treat fatigue in patients with breast cancer.
- Dietary supplements or diet patterns are seldom used to treat fatigue in patients with breast cancer.
- The results of this review showed that guarana extract and a diet rich in whole foods, omega-3 fatty acids, fruits, and vegetables could be used to treat CRF in patients with breast cancer.
- The studies had a low risk of bias with high-quality evidence on the efficacy of the interventions in treating fatigue in the study population.
Dietary interventions for multiple sclerosis-related outcomes
Parks NE et al. • The Cochrane database of systematic reviews (2020)
There are a variety of controlled trials addressing the effects of dietary interventions for MS with substantial variation in active treatment, comparator, and outcomes of interest.
- Among four trials comparing PUFAs with MUFAs, there may be little to no difference in global impression of deterioration (RR 0.85, 95% CI 0.71 to 1.03; 4 studies, 542 participants; 40% in the PUFA group versus 47% in the MUFA group; low-certainty evidence).
- In two trials comparing different PUFAs (omega-3 versus omega-6), there may be little to no difference in relapses (RR 1.02, 95% CI 0.62 to 1.66; 2 studies, 129 participants; 30% in the omega-3 versus 29% in the omega-6 group; low-certainty evidence).
- Among three trials comparing omega-3 with omega-6, there may be little to no difference in change in disability progression, measured as mean change in Expanded Disability Status Scale (EDSS) (mean difference (MD) 0.00, 95% CI -0.30 to 0.30; 3 studies, 166 participants; low-certainty evidence).
Acetyl-L-carnitine for patients with hepatic encephalopathy
Martí-Carvajal AJ et al. • The Cochrane database of systematic reviews (2019)
This Cochrane systematic review analysed a heterogeneous group of five trials at high risk of bias and with high risk of random errors conducted by only one research team.
- The effects of acetyl-L-carnitine compared with placebo on general health at 90 days are uncertain (MD -6.20 points, 95% confidence interval (CI) -9.51 to -2.89).
- Meta-analysis showed a reduction in blood ammonium levels favouring acetyl-L-carnitine versus placebo (MD -13.06 mg/dL, 95% CI -17.24 to -8.99; 387 participants; 5 trials; very low-quality evidence).
- It is unclear whether acetyl-L-carnitine versus placebo increases the risk of non-serious adverse events (8/126 (6.34%) vs 3/120 (2.50%); RR 2.51, 95% CI 0.68 to 9.22; 2 trials; very low-quality evidence).
The role of diet and non-pharmacologic supplements in the treatment of chronic neuropathic pain: A systematic review
Frediani JK et al. • Pain practice : the official journal of World Institute of Pain (2024)
Based on the review, we cannot recommend any supplement use for the management of CIPN, although further research into N-acetyl-cysteine, l-carnosine, crocin, and magnesium is warranted.
- Based on the review, we cannot recommend any supplement use for the management of CIPN, although further research into N-acetyl-cysteine, l-carnosine, crocin, and magnesium is warranted.
- Acetyl-l-carnitine was found to be likely ineffective or harmful.
- Alpha-lipoic acid was not found effective.
An integrated meta-analysis of peripheral blood metabolites and biological functions in major depressive disorder
Pu J et al. • Molecular psychiatry (2021)
This meta-analysis examined the effects of Acetyl-L-Carnitine.
- Pathway and network analyses revealed altered amino acid metabolism and lipid metabolism, especially for the tryptophan-kynurenine pathway and fatty acid metabolism, in the peripheral system of MDD patients.
- Our findings may facilitate biomarker development and the elucidation of the molecular mechanisms that underly MDD.© 2020.
- Further research warranted to confirm findings
L-acetylcarnitine for treating fragile X syndrome
Rueda JR et al. • The Cochrane database of systematic reviews (2015)
Low-quality evidence from two small trials showed that when compared to placebo, LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS.
- In one study, teachers' assessments of the children found no clear evidence of a difference (mean difference (MD) 0.50, 95% confidence interval (CI) -5.08 to 6.08, n = 51; low-quality evidence).
- Low-quality evidence from two small trials showed that when compared to placebo, LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS.
- Further research warranted to confirm findings
Metabolomic biomarkers for (R, S)-ketamine and (S)-ketamine in treatment-resistant depression and healthy controls: A systematic review
Kumar R et al. • Bipolar disorders (2024)
This systematic review provides preliminary evidence that ketamine may cause changes in several important pathways involved in energy metabolism and inflammation.
- This systematic review provides preliminary evidence that ketamine may cause changes in several important pathways involved in energy metabolism and inflammation.
- Larger and more rigorous studies are needed.
- Further research warranted to confirm findings