Letrozole
Potent non-steroidal aromatase inhibitor (Femara). Easy to over-suppress estrogen — small doses.
- Half-life
- 2.0 d
- Out of system
- ~10 days
- Route
- Oral
- Level
- Advanced
Levels carry over between doses — every 2–3 days is typical. After the last dose, roughly 97% has cleared in ~10 days (five half-lives) — the window that matters for washouts, bloodwork and surgery.
What Letrozole is used for
- The most potent aromatase inhibitor — for heavy aromatizing cycles or gyno reversal
- Can reverse early gynecomastia in some users
How it's typically used
Literature range: 0.5–2.5 mg every other day; start low and check estradiol.
What to watch for
- Very easy to crash estrogen to zero — small doses, slow adjustments
- Strong lethargy, joint pain, libido and lipid hits when over-used
- Prescription medicine; only with frequent bloodwork
About Ancillaries (SERMs / AIs)
- What they are
- Support drugs — SERMs, aromatase inhibitors, and prolactin controls used to manage the side effects of androgen use or to restart natural production afterwards.
- How they're run
- Oral tablets, dosed against bloodwork rather than on a fixed schedule.
- What to watch
- These are only meaningful with labs in hand. Crushing oestrogen with an AI wrecks joints, libido, and lipids just as thoroughly as having too much of it.
Full guide
Letrozole: A Tracking Guide for a Potent Aromatase Inhibitor
The strongest of the common AIs - and the easiest to crash estrogen with. Why low doses and labs matter most here.
Other ancillaries (serms / ais)
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.