(HealthDay News) – Patients with invasive malignancies who take L-carnitine supplements do not experience a reduction in fatigue, pain, or depression, according to research published online Sept 17 in the Journal of Clinical Oncology.

To determine whether L-carnitine improves fatigue in cancer patients, Ricardo A. Cruciani, MD, of the Beth Israel Medical Center in New York City, and colleagues conducted an Eastern Cooperative Oncology Group Phase 3, randomized, double-blind, placebo-controlled study involving 376 patients with invasive malignancies who received either 2g/day of L-carnitine oral supplement or matching placebo for four weeks.

The researchers found that fatigue, as measured using the Brief Fatigue Inventory, improved in both treatment arms compared with baseline, but there was no significant between-group difference. In a subgroup analysis, L-carnitine supplementation also did not improve fatigue in those who were carnitine-deficient at baseline. Neither depression nor pain was improved, as measured using the Functional Assessment of Chronic Illness Therapy-Fatigue instrument. The improvement in both arms suggests a large placebo effect.

“This is the largest clinical trial to date studying the effect of L-carnitine supplementation on patients with invasive malignancy and fatigue,” the authors write. “In this Phase 3, randomized, double-blind, placebo-controlled study, we observed that 1g twice daily of oral L-carnitine supplementation for four weeks does not improve fatigue, depression, or pain in patients with cancer.”

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