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Medications · Thyroid
Compounded T3 (Liothyronine)
Active triiodothyronine for thyroid hormone replacement.
What it does
What Compounded T3 (Liothyronine) is and why doctors prescribe it.
T3 (liothyronine) is the active form of thyroid hormone. While the manufactured supply offers T3 at fixed strengths, compounded T3 lets the prescribing doctor dial in custom strengths and dosage forms (immediate-release vs sustained-release) for patients whose clinical picture isn't well-served by the standard SKUs.
How it works
Mechanism in plain English.
T3 binds thyroid hormone receptors in target cells, regulating metabolism, body temperature, cardiovascular function, and energy production. Most circulating thyroid hormone is T4, which converts to T3 peripherally; some patients have impaired conversion or symptoms not relieved by T4-only therapy and benefit from direct T3 replacement at the dose their doctor selects.
How long it's been studied
Research history.
T3 has been used clinically since the 1950s. Modern thyroid-replacement guidelines from the American Thyroid Association inform combination T4/T3 prescribing. Compounded T3 is dispensed under 503A on doctor prescription, including slow-release forms not commercially available.
Dosing
Clinical context for the prescribing doctor.
Doctor-prescribed and lab-monitored. Compounded T3 is typically prescribed in the 5–25 mcg range, often divided across the day. Slow-release T3 may be dosed once or twice daily. Your doctor monitors TSH, free T3, and free T4 and adjusts based on symptoms and labs.
This page is informational, not a dispensing aid. Compounded T3 (Liothyronine) is dispensed only on a patient-specific prescription written by a licensed doctor for an identified patient. Compounded drugs are not FDA-approved and should not be evaluated using branded-drug trial data. Availability varies by state and prescribed medication.
How to access Compounded T3 (Liothyronine) through RonanRx
Three paths.
Doctors can prescribe compounded Compounded T3 (Liothyronine) for individual patients through RonanRx. Patients with a doctor can sign up to receive their prescription. Patients without a doctor can learn how the referral works.
Patient with a doctor
Sign up to receive your prescription.
If your doctor has already prescribed Compounded T3 (Liothyronine), sign up so we can prepare and ship your medication. The signup wizard collects intake and connects you to the prescribing workflow.
Patient without a doctor
Get referred by a partner clinic.
RonanRx prescribes through partner clinics — we don't initiate prescriptions on this site. Read how the referral process works and how to find a partner clinic in your state.