NCT07424183

T4/T3 Therapy in Hypothyroidism

• Status: Not Yet Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: University of Pennsylvania · Academic / Other
• Sex: All
• Age: 18 Years – 70 Years
• Healthy volunteers: Not accepted

Summary

This study will test whether 6 months of combination therapy with levothyroxine (LT4) plus liothyronine (LT3) is superior to LT4 plus placebo in participants with hypothyroidism who have residual symptoms of hypothyroidism with TSH levels within the reference range.

Detailed description

.Participants will * Take LT4+LT3 or LT4+placebo for 6 months * Visit the clinic at the beginning and the end of the study for a blood test and to answer questionnaires. * Have blood tests checked at 6 and 13 weeks and symptom checks by text (weekly to monthly)

Conditions

• Hypothyroidism Primary

Interventions

Type	Name	Description
DRUG	Liothyronine (L-T3)	Participants will either take LT3 with an LT4 dose that is reduced from baseline or they will take liothyronine placebo with their baseline LT4 dose.
DRUG	Levothyroxine Sodium (LT4) Tablets	All participants will take levothyroxine.
DRUG	Liothyronine (LT3) placebo	Identical placebo tablet without containing liothyronine

Timeline

• Start date: 2026-03-01
• Primary completion: 2027-03-01
• Completion: 2027-03-01
• First posted: 2026-02-20
• Last updated: 2026-02-23

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study