Protocol summary

Study aim
To evaluate the effects of taurine supplementation alongside methimazole on anxiety, sleep quality, fatigue, cortisol levels, thyroid hormones, blood pressure, heart rate, liver enzymes, and hematological parameters in patients with hyperthyroidism.
Design
This is a randomized, double-blind, placebo-controlled, parallel-group clinical trial involving 60 patients allocated in a 1:1 ratio using variable block randomization. Participants and outcome assessors will be blinded. Assessments will be conducted at baseline and after the four-week intervention.
Settings and conduct
The study will be conducted at a private endocrinology clinic in Dezful. Sixty patients will be recruited through consecutive sampling and randomly allocated to intervention and control groups after four weeks of methimazole stabilization. Taurine or placebo will be administered for four weeks, with assessments performed before and after the intervention.
Participants/Inclusion and exclusion criteria
Participants will include patients aged 18–60 years with clinically and laboratory-confirmed hyperthyroidism who have received methimazole at a daily dose of 10–20 mg for at least four weeks, are able to complete questionnaires, and provide informed consent. Proposed exclusion criteria include pregnancy and severe hepatic, renal, or cardiac disease at screening.
Intervention groups
Intervention group (n=30): Participants will receive oral taurine capsules at a dose of 500 mg once daily, 1–2 hours before bedtime, for four consecutive weeks, in addition to standard methimazole therapy at a daily dose of 10–20 mg. The intervention will begin after at least four weeks of methimazole treatment.
Main outcome variables
The primary outcome is the change in anxiety score measured using the 7 items Generalized Anxiety Disorder questionnaire at baseline and after four weeks of intervention, with changes compared between the two groups

General information

Reason for update
Acronym
IRCT registration information
IRCT registration number: IRCT20250502065563N4
Registration date: 2026-10-31, 1405/08/09
Registration timing: prospective

Last update: 2026-10-31, 1405/08/09
Update count: 0
Registration date
2026-10-31, 1405/08/09
Registrant information
Name
Ali Akbar Oroojan
Name of organization / entity
Country
Iran (Islamic Republic of)
Phone
+98 61 4242 9533
Email address
aliakbar_oroojan@yahoo.com
Recruitment status
Not yet recruiting
Funding source
Expected recruitment start date
2026-12-22, 1405/10/01
Expected recruitment end date
2027-12-22, 1406/10/01
Actual recruitment start date
empty
Actual recruitment end date
empty
Trial completion date
empty
Scientific title
Evaluation of the effect of taurine in patients with hyperthyroidism treated with methimazole: A two-group randomized placebo-controlled clinical trial
Public title
Effect of taurine in patients with hyperthyroidism
Purpose
Treatment
Inclusion/Exclusion criteria
Inclusion criteria:
Age between 18 and 60 years. Clinically and laboratory-confirmed hyperthyroidism. Receiving methimazole at a daily dose of 10–20 mg. At least four weeks since initiation of methimazole treatment. No use of taurine or other amino acid supplements during the previous four weeks. No regular use of sedatives, hypnotics, or medications affecting the central nervous system. Ability to complete the study questionnaires. Provision of written informed consent.
Exclusion criteria:
Presence of severe liver, kidney or heart disease at screening. Pregnancy at screening.
Age
From 18 years old to 60 years old
Gender
Both
Phase
2
Groups that have been masked
  • Participant
  • Care provider
  • Outcome assessor
  • Data analyser
Sample size
Target sample size: 60
More than 1 sample in each individual
Number of samples in each individual: 1
Collection of 5 cc of blood at two time points: at the beginning and at the end of the study.
Randomization (investigator's opinion)
Randomized
Randomization description
In this study, 60 eligible patients will be randomly allocated in a 1:1 ratio to the intervention and control groups after obtaining informed consent and completing methimazole stabilization. The unit of randomization will be the individual patient. An independent individual will generate the random allocation sequence using computer-generated random numbers. Variable block randomization will be used. No stratification is planned. The allocation list will remain confidential, and group assignments must be concealed from the person enrolling participants until each patient is assigned.
Blinding (investigator's opinion)
Double blinded
Blinding description
Participants, outcome assessors, and the statistical analyst will be blinded to treatment allocation. Taurine and placebo capsules will be identical in appearance, color, size, and packaging and will be coded. Allocation codes will remain confidential until completion of the final data analysis.
Placebo
Used
Assignment
Parallel
Other design features

Secondary Ids

empty

Ethics committees

1

Ethics committee
Name of ethics committee
Ethics committee of Dezful University of Medical Sciences
Street address
Khuzestan Province, Dezful, End of Azadegan Boulevard, Next to the Traffic Police Department, Iran
City
Dezful
Province
Khouzestan
Postal code
6461653476
Approval date
2026-10-07, 1405/07/15
Ethics committee reference number
IR.DUMS.REC.1405.072

Health conditions studied

1

Description of health condition studied
Hyperthyroidism
ICD-10 code
E05
ICD-10 code description
Thyrotoxicosis [hyperthyroidism]

Primary outcomes

1

Description
The primary outcome is the change in anxiety score measured using the seven-item Generalized Anxiety Disorder questionnaire at baseline and after four weeks of intervention, with changes compared between the two groups.
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
The seven-item Generalized Anxiety Disorder questionnaire, with scores ranging from 0 to 21; higher scores indicate greater anxiety severity.

Secondary outcomes

1

Description
Change in sleep quality score assessed using the Pittsburgh Sleep Quality Index
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Pittsburgh Sleep Quality Index questionnaire, with scores ranging from 0 to 21; higher scores indicate poorer sleep quality.

2

Description
Change in mean fatigue severity score assessed using the Fatigue Severity Scale
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Fatigue Severity Scale consisting of nine items rated on a seven-point scale; the final score is the mean of the nine item scores.

3

Description
Change in serum cortisol concentration
Timepoint
At baseline and at the end of the fourth week, between 7:00 and 9:00 AM.
Method of measurement
Measurement of serum cortisol concentration after 8–12 hours of fasting using the enzyme-linked immunosorbent assay or a standard laboratory method.

4

Description
Changes in serum thyroid-stimulating hormone, free thyroxine, and triiodothyronine levels
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of serum thyroid hormone concentrations using the enzyme-linked immunosorbent assay.

5

Description
Changes in systolic and diastolic blood pressure
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of systolic and diastolic blood pressure using a calibrated digital blood pressure monitor after at least five minutes of seated rest. The mean of two consecutive measurements will be recorded in millimeters of mercury.

6

Description
Change in heart rate measured in beats per minute
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of heart rate using a calibrated digital blood pressure monitor after at least five minutes of seated rest.

7

Description
Changes in serum alanine aminotransferase and aspartate aminotransferase activities
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of liver enzyme activities using standard enzymatic colorimetric assays and an automated biochemistry analyzer.

8

Description
Changes in complete blood count parameters
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of complete blood count parameters using an automated hematology analyzer.

9

Description
Change in serum C-reactive protein concentration
Timepoint
At baseline and at the end of the fourth week of intervention.
Method of measurement
Measurement of serum C-reactive protein concentration using a standard laboratory assay.

Intervention groups

1

Description
Intervention group (n=30): Participants will receive oral taurine capsules at a dose of 500 mg once daily, 1–2 hours before bedtime, for four consecutive weeks, in addition to standard methimazole therapy at a daily dose of 10–20 mg. The intervention will begin after at least four weeks of methimazole treatment.
Category
Treatment - Drugs

2

Description
Control group (n=30): Participants will receive methimazole at a daily dose of 10–20 mg along with placebo capsules identical to taurine in appearance, color, size, and packaging. The placebo will be administered once daily, 1–2 hours before bedtime, for four consecutive weeks.
Category
Placebo

Recruitment centers

1

Recruitment center
Name of recruitment center
Private Endocrinology and Metabolism Clinic, Dezful, Iran
Full name of responsible person
Hamid Karimi
Street address
Neshat 1 Medical Complex, Taleghani Street, Dezful, Iran.
City
Dezful
Province
Khouzestan
Postal code
6461796455
Phone
+98 61 4225 2840
Email
Karimi.h@dums.ac.ir

Sponsors / Funding sources

1

Sponsor
Name of organization / entity
Dezfoul University of Medical Sciences
Full name of responsible person
Abbas Heidarimoghadam
Street address
Next to the Traffic Police Department, End of Azadegan Boulevard, Dezful, Khuzestan Province, Iran.
City
Dezful
Province
Khouzestan
Postal code
6461653476
Phone
+98 61 4242 2710
Email
research.dums@gmail.com
Grant name
Grant code / Reference number
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
Dezfoul University of Medical Sciences
Proportion provided by this source
100
Public or private sector
Public
Domestic or foreign origin
Domestic
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
Academic

Person responsible for general inquiries

Contact
Name of organization / entity
Dezfoul University of Medical Sciences
Full name of responsible person
Ali Akbar Oroojan
Position
Associate professor
Latest degree
Ph.D.
Other areas of specialty/work
Physiology
Street address
School of Medicine, Dezful University of Medical Sciences, Azadegan Street, Dezful, Khuzestan Province, Iran.
City
Dezful
Province
Khouzestan
Postal code
6461653476
Phone
+98 61 4242 2710
Email
aliakbar_oroojan@yahoo.com

Person responsible for scientific inquiries

Contact
Name of organization / entity
Dezfoul University of Medical Sciences
Full name of responsible person
Ali Akbar Oroojan
Position
Associate professor
Latest degree
Ph.D.
Other areas of specialty/work
Physiology
Street address
School of Medicine, Dezful University of Medical Sciences, Azadegan Street, Dezful, Khuzestan Province, Iran.
City
Dezful
Province
Khouzestan
Postal code
6461653476
Phone
+98 61 4242 2710
Email
aliakbar_oroojan@yahoo.com

Person responsible for updating data

Contact
Name of organization / entity
Dezfoul University of Medical Sciences
Full name of responsible person
Ali Akbar Oroojan
Position
Associate professor
Latest degree
Ph.D.
Other areas of specialty/work
Physiology
Street address
School of Medicine, Dezful University of Medical Sciences, Azadegan Street, Dezful, Khuzestan Province, Iran.
City
Dezful
Province
Khouzestan
Postal code
6461653476
Phone
+98 61 4242 2710
Email
aliakbar_oroojan@yahoo.com

Sharing plan

Deidentified Individual Participant Data Set (IPD)
Undecided - It is not yet known if there will be a plan to make this available
Study Protocol
Undecided - It is not yet known if there will be a plan to make this available
Statistical Analysis Plan
Not applicable
Informed Consent Form
Undecided - It is not yet known if there will be a plan to make this available
Clinical Study Report
Undecided - It is not yet known if there will be a plan to make this available
Analytic Code
Not applicable
Data Dictionary
Not applicable
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