Effects of L-carnitine on Hypothyroidism

This study has been completed.
IlDong Pharmaceutical Co Ltd
Information provided by (Responsible Party):
Sin Gon Kim, Korea University Anam Hospital
ClinicalTrials.gov Identifier:
First received: January 10, 2013
Last updated: December 2, 2013
Last verified: December 2013

L-carnitine and thyroid hormone tended to antagonize reciprocally in human body. Urinary excretion of L-carnitine decreased in hypothyroid patients, and levothyroxine supplementation increased excretion of L-carnitine. The investigators hypothesized that supplying L-carnitine to hypothyroid patients with fatigue symptom could improve the quality of life, and fatigue score in them. Therefore, the investigators planned to compare the efficacy of L-carnitine and placebo in hypothyroid patients who had taken levothyroxine.

Condition Intervention Phase
Drug: L-carnitine
Drug: Placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: Single-center, Randomized, Double-Blinded, Comparative Study of the Effectiveness of L-carnitine in Patients'Fatigue Degree Changing With Hypothyroidism Who Take Levothyroxine

Resource links provided by NLM:

Further study details as provided by Korea University Anam Hospital:

Primary Outcome Measures:
  • Fatigue Severity scale [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: Yes ]
    Change from Baseline in Fatigue severity scale at 12 weeks (scoring `fatigue severity scale` at baseline and 12 weeks)

Secondary Outcome Measures:
  • Wessely and Powell score [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: Yes ]
    Change from Baseline in Wessely and Powell score at 12 weeks (scoring `Wessely and Powell score` at baseline and 12 weeks)

Other Outcome Measures:
  • thyroid function test [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    measure thyroid-stimulating hormone and free T4 at baseline and 12 weeks

Enrollment: 60
Study Start Date: August 2012
Study Completion Date: June 2013
Primary Completion Date: June 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: L-carnitine
L-carnitine 330mg, 3 tablet twice daily
Drug: L-carnitine
Placebo Comparator: Placebo
placebo drug, 3 tablet twice daily
Drug: Placebo


Ages Eligible for Study:   20 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Clinical diagnosis of hypothyroidism with fatigue symptom
  • Currently use of the same amount of levothyroxine over at least six months
  • Normal serum free T4 level

Exclusion Criteria:

  • Current smoker
  • Serum hemoglobin level of under 12mg/dL
  • Clinical diagnosis of diabetes mellitus or fasting serum glucose level ≥ 126mg/dL or HbA1c level ≥ 6.5%
  • History of significant heart failure
  • History of large amount of alcohol consumption
  • Uncontrolled hypertension (systolic blood pressure ≥ 160 millimeter of mercury (mmHg) or diastolic blood pressure ≥ 100 mmHg
  • pregnant, or planning to be pregnant, or breast feeding women
  • aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥ 2 times of normal limit
  • serum Cr level > 2.0mg/dL
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01769157

Korea, Republic of
Korea University Anam Hospital
Seoul, Korea, Republic of
Sponsors and Collaborators
Korea University Anam Hospital
IlDong Pharmaceutical Co Ltd
  More Information

No publications provided

Responsible Party: Sin Gon Kim, Professor, Korea University Anam Hospital
ClinicalTrials.gov Identifier: NCT01769157     History of Changes
Other Study ID Numbers: LC-TH-1101
Study First Received: January 10, 2013
Last Updated: December 2, 2013
Health Authority: Korea: Food and Drug Administration

Additional relevant MeSH terms:
Thyroid Diseases
Endocrine System Diseases
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on April 16, 2014