Efficacy of L-carnitine supplementation on frailty status and its biomarkers, nutritional status, and physical and cognitive function among prefrail older adults: a double-blind, randomized, placebo-controlled clinical trial

Clin Interv Aging. 2016 Nov 17;11:1675-1686. doi: 10.2147/CIA.S113287. eCollection 2016.


Background: Frailty is a biological syndrome of decreased reserve and resistance to stressors due to decline in multiple physiological systems. Amino acid deficiency, including L-carnitine, has been proposed to be associated with its pathophysiology. Nevertheless, the efficacy of L-carnitine supplementation on frailty status has not been documented. Thus, this study aimed to determine the effect of 10-week L-carnitine supplement (1.5 g/day) on frailty status and its biomarkers and also physical function, cognition, and nutritional status among prefrail older adults in Klang Valley, Malaysia.

Methodology: This study is a randomized, double-blind, placebo-controlled clinical trial conducted among 50 prefrail subjects randomized into two groups (26 in L-carnitine group and 24 in placebo group). Outcome measures include frailty status using Fried criteria and Frailty Index accumulation of deficit, selected frailty biomarkers (interleukin-6, tumor necrosis factor-alpha, and insulin-like growth factor-1), physical function, cognitive function, nutritional status and biochemical profile.

Results: The results indicated that the mean scores of Frailty Index score and hand grip test were significantly improved in subjects supplemented with L-carnitine (P<0.05 for both parameters) as compared to no change in the placebo group. Based on Fried criteria, four subjects (three from the L-carnitine group and one from the control group) transited from prefrail status to robust after the intervention.

Conclusion: L-carnitine supplementation has a favorable effect on the functional status and fatigue in prefrail older adults.

Keywords: Frailty Index accumulation of deficit; Fried criteria; L-carnitine supplementation; frailty; frailty biomarkers; physical function; prefrail elderly; randomized controlled clinical trial.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Biomarkers
  • Carnitine / administration & dosage*
  • Cognition*
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Frailty / drug therapy*
  • Hand Strength
  • Health Status*
  • Humans
  • Insulin-Like Growth Factor I / analysis
  • Interleukin-6 / blood
  • Malaysia
  • Male
  • Middle Aged
  • Nutritional Status
  • Tumor Necrosis Factor-alpha / blood


  • Biomarkers
  • Interleukin-6
  • Tumor Necrosis Factor-alpha
  • Insulin-Like Growth Factor I
  • Carnitine