Liothyronine

Cytomel

Other GLP-1 TRT HRT Oral FDA/EMA Label

Half-life

24 hr

Time to Peak

2.5 hr

Steady State

~5 days

Bioavailability

95%

Dose Range

5–75 mcg

Frequency

once daily

Overview

Synthetic T3 (triiodothyronine) — the active thyroid hormone. Faster onset and shorter duration than levothyroxine. Sometimes added to T4 therapy or used in bodybuilding/weight loss contexts for metabolic rate enhancement.

Mechanism of Action

Synthetic L-triiodothyronine (T3), the biologically active thyroid hormone. Binds nuclear thyroid receptors directly without requiring peripheral conversion. ~3-5x more potent than T4.

Dosing Information

Route	Dose Range	Half-life	Tmax	Frequency
Oral	5–75 mcg	24 hr	2.5 hr	once daily, Twice daily

Used in Regimens

Liothyronine is not currently part of any catalog regimen.

Data Sources

FDA Label Cytomel (liothyronine) FDA Prescribing Information

Related Tools

Medication Level Plotter

See blood level curves for this compound

Dose Calculator

Calculate reconstitution and draw volumes

Split Dose Calculator

Divide your weekly dose into multiple injections

Track Liothyronine with Doseline

Reminders, medication level charts, injection site rotation, and protocol tracking — all free, all private.

Join the waitlist

Doseline provides informational tools only. It is not a medical device and does not provide medical advice. Always consult a qualified healthcare provider.