Liothyronine (T3)
The synthetic form of the active thyroid hormone T3, prescribed for hypothyroidism and used off-label to accelerate fat loss. Exogenous dosing suppresses natural thyroid output.
- Half-life
- 1.0 d
- Out of system
- ~5 days
- Route
- Oral
- Level
- Advanced
Daily dosing holds steady levels. After the last dose, roughly 97% has cleared in ~5 days (five half-lives) — the window that matters for washouts, bloodwork and surgery.
What Liothyronine (T3) is used for
- Directly replaces active thyroid hormone in true hypothyroidism
- Raises metabolic rate, which can accelerate fat loss
- Faster-acting than the T4 hormone levothyroxine
How it's typically used
Clinical and anecdotal reports describe roughly 25-75 mcg daily, framed as reported practice and not a recommendation.
What to watch for
- Suppresses your own thyroid output, creating dependence with misuse
- Excess dosing risks muscle loss, bone loss, and cardiac strain
- Can trigger palpitations, anxiety, and heat intolerance
- A prescription medication; use outside medical supervision is unsafe and unapproved
About Other research compounds
- What they are
- Nootropics, metabolic agents, and research compounds that don't fit the other classes.
- How they're run
- Route and schedule vary widely — check the individual entry.
- What to watch
- This is the least-characterised corner of the atlas. Read the full guide, and treat anything without published human data as exactly that.
Full guide
T3 (Liothyronine): A Tracking Guide for a Synthetic Thyroid Hormone
A measured look at liothyronine (T3), why it is used for fat loss, and the muscle and cardiac risks that come with suppressing your own thyroid.
Other other research compounds
Peptid AI is an educational and self-tracking tool — not a medical service, and not a vendor. Nothing here is medical advice, a prescription, or an endorsement. Doses reflect what is commonly reported in research literature; they are not recommendations. Many compounds listed are experimental, not approved for human use, and/or controlled substances that are illegal to possess without a prescription in many countries. Always consult a qualified physician before starting, changing, or stopping any protocol.