Stopping low-dose levothyroxine in older adults with mild underactive thyroid
Tests stopping levothyroxine versus continuing it in older adults with subclinical hypothyroidism.
Key facts
- Who runs it
- Spyridoula Maraka
- Where
- Gainesville, Little Rock, and Rochester, United StatesSee the 3 sites
- Trial code
- Registry title
- Discontinuation of Low-Dose Levothyroxine in Older Adults With Subclinical Hypothyroidism
- Status
- Not yet recruiting
- Phase
- Phase 4
- People taking part
- 138 people, planned
- Starts
- Oct 2027
- Expected to end
- Sept 2031
- Type of study
- Interventional, 2 groupsOne group gets an existing treatment, for comparison.
- Treatments tested
- Levothyroxine Pill
- Placebo
- Record updated
- 26 August 2026
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults aged 65 or older who take low-dose levothyroxine for subclinical hypothyroidism (a mildly underactive thyroid). It tests whether stopping the drug is safe, compared with continuing it.
- Age
- 65 years or older
- Sex
- All sexes
- Disease stage
- Subclinical hypothyroidism: before treatment, TSH was above the normal range but <10 mIU/L, with normal fT4. Thyroid tests (TSH and fT4) must now be in the normal range.
- Earlier treatment
- Must have taken levothyroxine for subclinical hypothyroidism for at least 6 months. Dose must be ≤50 mcg/day, or ≤25 mcg/day if weighing <50 kg (110 lb). Must have had outpatient care at the study site for at least 12 months.
- Biomarker or test result
- TSH and fT4 within the normal range at enrolment. TSH never >10 mIU/L in the health record.
Main reasons for not taking part
- Taking drugs that affect thyroid hormones, such as antithyroid drugs, amiodarone or lithium
- Past thyroid cancer, goiter pressing on the neck, thyroid surgery or radioactive iodine therapy
- NYHA Class IV heart failure, or a hospital stay for major illness or surgery in the last 4 weeks
- LDL cholesterol >190 mg/dL (4.9 mmol/L)
- Untreated depression, uncontrolled mental illness, chronic fatigue syndrome or pain, or life expectancy under 6 months
The registry criteria, word for word
Show all 21 criteriaShow less
Who can take part
- Age ≥65 years
- Euthyroid at the time of enrollment, defined as thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels within the reference range
- Receiving levothyroxine treatment for subclinical hypothyroidism for at least 6 months
- Receiving levothyroxine at a dose ≤50 mcg/day, or ≤25 mcg/day for participants weighing <50 kg
- Receiving outpatient care at the participating study site for at least 12 months; Subclinical hypothyroidism is defined as a TSH level above the normal reference range but <10 mIU/L, with a normal fT4 level, prior to initiation of levothyroxine therapy
Who cannot take part
- Levothyroxine therapy initiated less than 6 months before enrollment
- Current use of medications that affect thyroid hormone levels, such as antithyroid medications, amiodarone, or lithium
- Hospitalization for a major illness or elective surgery within the previous 4 weeks, including acute coronary syndrome, acute myocarditis, pancarditis, or stroke
- History of thyroid cancer or goiter with compressive symptoms
- History of partial or total thyroidectomy or radioactive iodine therapy
- New York Heart Association (NYHA) Class IV heart failure
- Unstable medical condition that, in the investigator's judgment, would jeopardize participant safety or interfere with study participation
- Terminal illness with a life expectancy of less than 6 months
- Uncontrolled psychiatric disorder
- Uncontrolled chronic fatigue syndrome
- Severe dyslipidemia, defined as LDL cholesterol >190 mg/dL
- TSH >10 mIU/L at any time documented in the institutional electronic health record
- Abnormal thyroid function at the time of enrollment
- Lack of decision-making capacity
- Untreated depression
- Uncontrolled pain
Where in United States
- University of Florida Clinical Research CenterGainesville, United StatesContact: Naykky Singh Ospina, M.D., M.S.Not yet recruiting
- Central Arkansas Veterans Healthcare SystemLittle Rock, United StatesContact: Spyridoula Maraka, M.D., M.S.Not yet recruiting
- Mayo ClinicRochester, United StatesContact: Juan Pablo Brito Campana, M.B.B.S.Not yet recruiting
About the trial
What the trial wants to find out
The goal of this clinical trial is to learn whether low-dose levothyroxine can be safely discontinued in adults aged 65 years or older who are taking levothyroxine for subclinical hypothyroidism. The study will also evaluate the cost-effectiveness of discontinuing levothyroxine.
Read full original descriptionShow less
The main questions it aims to answer are:
* Does discontinuing levothyroxine result in no clinically meaningful worsening of thyroid-related symptoms compared with continuing levothyroxine? * What are the effects of discontinuing levothyroxine on quality of life, tiredness, cognition, thyroid hormone levels, lipid levels, weight, and adverse events? * Is discontinuing levothyroxine cost-effective compared with continuing treatment?
Researchers will compare participants who discontinue levothyroxine and receive placebo with participants who continue their current dose of levothyroxine to determine the effects of levothyroxine discontinuation.
Participants will:
* Complete a 2-week run-in period during which they continue their usual levothyroxine and record their medication use. * Eligible participants will be randomly assigned to either continue their current dose of levothyroxine or receive a matching placebo for 6 months. Participants, their clinicians, and study investigators will not know which treatment they are receiving during the study. * Complete study assessments at baseline, approximately 2 months, and 6 months. Assessments will include blood tests, measurements such as body weight, questionnaires about thyroid-related symptoms and quality of life, and assessments of cognition and other health outcomes.
The 2 groups in the trial
- Levothyroxine ContinuationExisting treatment, for comparison
Participants will continue their pre-study dose of levothyroxine for 6 months using blinded study medication.
Treatment: Levothyroxine Pill
- Levothyroxine DiscontinuationTreatment being tested
Participants will discontinue levothyroxine and receive matching placebo for 6 months using blinded study medication.
Treatment: Placebo
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Discontinuation of Low Dose Levothyroxine Therapy for Older Adults With Subclinical Hypothyroidism: a Randomized, Double-blinded, Placebo-controlled Study
- Plain-language title
- Stopping low-dose levothyroxine in older adults with mild underactive thyroidGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 14 November 2026.
- Record updated
- 26 August 2026