What is Letrozole?
Letrozole is a third-generation non-steroidal aromatase inhibitor (Type II — reversible competitive CYP19A1 inhibition). ~99% estrogen suppression — most potent AI. Research: estrogen-sensitive cancer, T:E2 ratio manipulation, aromatase kinetics, male hypogonadism from aromatase excess, and Type I vs Type II AI comparison. CAS 112809-51-5.
Research Applications
Aromatase Inhibition
Reversible CYP19A1 competitive inhibition — ~99% estrogen suppression
Hormone-Sensitive Cancer
ER+ breast cancer estrogen deprivation models
T:E2 Ratio Manipulation
Testosterone/estradiol ratio titration in male models
AI Class Comparison
Non-steroidal (reversible) vs steroidal/irreversible AI mechanisms
Male Hypogonadism
Aromatase excess syndrome — estrogen-driven gonadotropin suppression
Quick Specs
| Form |
C₁₇H₁₁N₅ |
| Purity |
≥99% by HPLC — every batch |
| CAS Number |
112809-51-5 |
| Molecular Weight |
MS molecular weight confirmed — every batch |
| Specification |
≥99% by HPLC — every batch |
| Shelf Life |
24 months unopened |
| Storage |
Room temperature sealed | cool, dry storage |
| Manufacture |
In-house synthesis — Qingdao, China |
| Brand |
China |
Frequently Asked Questions
How do I reconstitute this peptide?
QSC research tablets are supplied as pre-dosed oral tablets at the stated concentration. No reconstitution is required. Each tablet is compressed at uniform dose for consistent dosing in research applications.
How should this peptide be stored?
Store at room temperature (15–25°C) in a cool, dry place away from moisture, heat, and direct sunlight. Keep in the original container. Properly stored tablets remain stable for 2–3 years.
What purity is this QSC compound and how is it verified?
QSC research tablets contain active ingredient at ≥99% HPLC purity before tableting, with MS-confirmed identity on every batch. COA is published on the product page and independently verifiable at verify.janoshik.com.
🧪 Peptide Research Tools: Use QSC's free
peptide calculators — reconstitution, BAC water, dosing, half-life, and mixing charts.
🌍 Domestic shipping: 🇺🇸 USA 5–7 days
🌏 International shipping: 7–14 days
⚠️ RESEARCH USE ONLY — NOT FOR HUMAN CONSUMPTION
QSC products are strictly for in vitro and in vivo laboratory research.
Safety & Handling
🚫
Not for Human Use
These compounds are for research only.
🥽
PPE Required
Always use appropriate protective equipment.
❄️
Storage Compliance
Follow product-specific storage conditions.
Product-Specific Storage
Room temperature sealed | cool, dry storage
