L-Carnitine and Improved Quality of Life

Research synthesisLow evidenceMixed effect size4 studies · 2 beneficial · 2 neutral · 0 harmful

Across 4 studies, 2 reported beneficial effects and 2 were neutral, with no harmful effects, indicating mixed but cautiously positive evidence for L-carnitine improving quality of life. The predominant effect size among beneficial studies was small to moderate, and the median study duration was 84 days (12 weeks). Most evidence comes from clinical populations with specific conditions (liver cirrhosis, migraine, BPH, COPD), and the most commonly tested dose was between 500 mg/day and 2 g/day.

Effective dose range: 500 mg/day to 2 g/day
Studied populations: patients with liver cirrhosis and covert hepatic encephalopathy, women with migraine, older men with benign prostatic hyperplasia, and individuals with chronic obstructive pulmonary disease

Caveats: Evidence base is small (only 4 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. Results are largely from specific clinical populations and may not generalize to healthy adults. One study with a neutral finding showed significant within-group improvement but no between-group difference, complicating interpretation.

Generated Jun 12, 2026

Doses used in studies

g/day: 2 (median 2, IQR 2–2) — 1 study
mg/day: 500 (median 500, IQR 500–500) — 1 study

Time to effect

Median: 2.8 months · IQR 10 weeks–4.2 months · Range 8 weeks–5.6 months — Reported in 3 of 4 studies

Safety in these studies

Overall tolerabilityReported
we propose broader research and implementation of this nutraceutical agent as an effective, inexpensive, and safe adjuvant therapeutic for the long-term management of COPD patients
from: Targeting Skeletal Muscle Dysfunction With L-Carnitine for the Treatment of Patients With

4 of 4 papersPopulation:

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study.
- 2022-07-01
- RCT · n = 150
- The Korean journal of internal medicine 37(4)
- - Eileen L Yoon
  - Sang Bong Ahn
  - Dae Won Jun
  - Yong Kyun Cho
  - Do Seon Song
  - Jae Yoon Jeong
  - Hee Yeon Kim
  - Young Kul Jung
  - Myeong Jun Song
  - Sung Eun Kim
  - Hyoung Su Kim
  - Soung Won Jeong
  - Sang Gyune Kim
  - Tae Hee Lee
- PubMed: 35526858
- DOI: 10.3904/kjim.2021.338
7 Insights on
- Improved Quality of Life
- High evidence
- Large Human Trial
- Clinical
total SF-36 score significantly improved in the L-carnitine group after 24 weeks ... however, these values were comparable between the two groups.
Effect
Neutral
Effect size
Small
Significant
No
Dose
2 g/day
Investigating the effects of co-supplementation with alpha-linolenic acid and L-carnitine on inflammatory status, oxidative stress, clinical symptoms, mental health and quality of life in women with migraine: a protocol for a randomized, triple-blind, placebo-controlled trial.
- 2024-10-08
- RCT · n = 80
- Trials 25(1)
- - Sahar Golpour-Hamedani
  - Mohammad Bagherniy
  - Fariborz Khorvash
  - Awat Feizi
  - Manoj Sharma
  - Gholamreza Askari
- PubMed: 39380085
- DOI: 10.1186/s13063-024-08500-3
11 Insights on
- Improved Quality of Life
- High evidence
- Clinical
Secondary outcomes include mental health, sleep quality, and quality of life (QOL)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
500 mg/day
Effects of L-Carnitine and Coenzyme Q10 Supplementation on Lower Urinary Tract Symptoms in Men with Benign Prostatic Hyperplasia: A Randomized, Controlled, Clinical Trial.
- 2023-12-17
- RCT
- Nutrition and cancer 76(2)
- - Mahsa Norouzi
  - Sepideh Mahboobi
  - Mohammad Hassan Eftekhari
  - Mehdi Salehipour
  - Haleh Ghaem
  - Ali Mirzakhanlouei
  - Mohammad Ali Mohsenpour
- PubMed: 38105612
- DOI: 10.1080/01635581.2023.2295578
5 Insights on
- Improved Quality of Life
- High evidence
- Clinical
However, there were no significant between-group differences in IPSS (p = 0.503), QoL scores (p = 0.339), and PSA levels (p = 0.482).
Effect
Neutral
Effect size
Small
Significant
No
Targeting Skeletal Muscle Dysfunction With L-Carnitine for the Treatment of Patients With Chronic Obstructive Pulmonary Disease.
- 2023
- Review
- In vivo (Athens, Greece) 37(4)
- - Ba X Hoang
  - B O Han
  - William H Fang
  - Anh K Nguyen
  - David G Shaw
  - Cuong Hoang
  - Hau D Tran
- PubMed: 37369514
- DOI: 10.21873/invivo.13224
2 Insights on
- Improved Quality of Life
- Low evidence
This review shows how skeletal muscle dysfunction and metabolic abnormalities contribute significantly to COPD patients' symptoms, functional activities, quality of life, and overall disease outcomes. Based on the clinical evidence of L-carnitine and derivatives as metabolic and muscle bioenergetic enhancers, we propose broader research and implementation of this nutraceutical agent as an effective, inexpensive, and safe adjuvant therapeutic for the long-term management of COPD patients.
Effect
Beneficial
Effect size
Small
Significant
Yes

L-Carnitine and Improved Quality of Life

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study.

Investigating the effects of co-supplementation with alpha-linolenic acid and L-carnitine on inflammatory status, oxidative stress, clinical symptoms, mental health and quality of life in women with migraine: a protocol for a randomized, triple-blind, placebo-controlled trial.

Effects of L-Carnitine and Coenzyme Q10 Supplementation on Lower Urinary Tract Symptoms in Men with Benign Prostatic Hyperplasia: A Randomized, Controlled, Clinical Trial.

Targeting Skeletal Muscle Dysfunction With L-Carnitine for the Treatment of Patients With Chronic Obstructive Pulmonary Disease.