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Hormone Therapy

Armour Thyroid vs Synthetic T4 for Hypothyroidism

Phase 2 & 3
Research Sponsored by AbbVie
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Be on a stable FDA-approved daily dose of synthetic T4 prior to the Screening visit, and must be taking synthetic T4 dose of at least 25 mcg at Screening visit. Must enter the study using the same stable dose to determine dose conversion
Be older than 18 years old
Must not have
Known or suspected allergy or intolerance to any ingredients of Armour Thyroid, including its excipients, synthetic T4, other thyroid replacement medications, or pork products
Screening 3 weeks
Treatment Varies
Follow Up up to approximately 90 weeks
Awards & highlights


This trial will compare the effectiveness and safety of Armour Thyroid with synthetic T4 in people with hypothyroidism who are currently stable on synthetic T4. It will also assess how well patients respond

Who is the study for?
This trial is for adults with primary hypothyroidism who have been stable on synthetic T4 therapy for at least a year. Participants must have had their thyroid condition diagnosed over 12 months ago and show consistent in-range thyroid-stimulating hormone (TSH) levels.Check my eligibility
What is being tested?
The study compares Armour Thyroid, a natural desiccated thyroid medication, to synthetic T4 (Levothyroxine) in treating hypothyroidism. It will assess the safety and effectiveness of switching from synthetic T4 to Armour Thyroid.See study design
What are the potential side effects?
Potential side effects may include changes in energy levels, heart rate fluctuations, weight changes, sensitivity to heat or cold, hair thinning, and mood swings which are common symptoms associated with adjusting thyroid medications.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
I am taking a stable dose of synthetic thyroid hormone (T4) of at least 25 mcg daily.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
I am allergic to Armour Thyroid or its ingredients, synthetic T4, other thyroid meds, or pork.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~up to approximately 90 weeks
This trial's timeline: 3 weeks for screening, Varies for treatment, and up to approximately 90 weeks for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Number of Participants with Adverse Events (AEs)
Percentage of Participants who Achieve Thyroid-Stimulating Hormone (TSH) Response
Secondary outcome measures
Frequency of Dose Titrations During the Double-Blind (DB) Period Among Participants who Achieved TSH Response at the End of the DB Period
Number of Participants Needing Altered Dose Conversion from Synthetic T4 to Armour Thyroid
Percentage of Participants who Achieve TSH Response

Trial Design

2Treatment groups
Experimental Treatment
Group I: Group 2Experimental Treatment2 Interventions
Participants will alternate between Armour Thyroid and synthetic T4 for up to 81 weeks.
Group II: Group 1Experimental Treatment1 Intervention
Participants will receive Armour Thyroid for up to 81 weeks.
First Studied
Drug Approval Stage
How many patients have taken this drug
Completed Phase 4

Find a Location

Who is running the clinical trial?

AbbVieLead Sponsor
983 Previous Clinical Trials
506,561 Total Patients Enrolled
ABBVIE INC.Study DirectorAbbVie
414 Previous Clinical Trials
149,092 Total Patients Enrolled
~1867 spots leftby Jun 2028