Letrobol (Letrozole 2.5 mg)

Letrobol (Letrozole 2.5 mg) is Evolve Biolabs' high-potency non-steroidal aromatase inhibitor, supplied as 50 tablets in sealed blister strips. It produces the most complete oestrogen suppression of the commonly researched aromatase inhibitors.

What Letrobol Is

Letrozole is a third-generation non-steroidal aromatase inhibitor that binds the aromatase enzyme with very high affinity. Aromatase converts androgens such as androstenedione and testosterone into oestrone and oestradiol, so inhibiting it sharply reduces circulating oestrogen. Letrozole is more potent than anastrozole at standard doses and is orally active with good absorption. Letrobol supplies the clinical 2.5 mg strength across 50 tablets.

The History of Femara

Letrozole was developed by Ciba-Geigy and approved in 1997 as Femara for advanced breast cancer in postmenopausal women. It later became a standard adjuvant therapy after the BIG 1-98 trial compared it with tamoxifen and demonstrated improved outcomes. Letrozole has also been studied for ovulation induction, where it has challenged clomiphene as a first-line option. Its potency and consistency made it a benchmark aromatase inhibitor.

How It Works

At the aromatase active site, letrozole occupies the space normally used by androstenedione and testosterone. Its binding is reversible, but its affinity is high enough that even brief occupancy produces marked enzyme inhibition. Oestrogen synthesis falls in fat, muscle and other peripheral tissues, and the pituitary responds to the loss of negative feedback by releasing more gonadotropin. Clearance is hepatic, excretion is largely renal, and the terminal half-life is about two days.

What the Research Shows

• The BIG 1-98 trial compared letrozole with tamoxifen in early breast cancer.
• Letrozole is established as adjuvant therapy in postmenopausal hormone-receptor-positive disease.
• Ovulation-induction trials have compared letrozole directly with clomiphene.
• Studies consistently show near-complete suppression of circulating oestradiol.

Research Context

Letrozole's potency makes it a useful tool for studying what happens when oestrogen is almost completely removed. In ovulation research it has produced comparable or better pregnancy rates than clomiphene in some trials, with fewer anti-oestrogenic effects on the endometrium. In oncology, the BIG 1-98 programme compared letrozole with tamoxifen and with sequential regimens, and the results established it as a standard adjuvant option. Bone density and lipid changes are the most studied long-term consequences of that degree of suppression.

Strength, Pack and Authentication

Each tablet contains 2.5 mg of letrozole USP, with 50 tablets per pack. The tablets are sealed in moisture-resistant blister strips inside a printed, tamper-evident carton stating the compound, strength and tablet count. A verification code on the packaging can be checked against Evolve Biolabs' records, and the blister format protects each dose from moisture and light.

Buying Letrobol Online

Femara remains one of the most searched aromatase inhibitors. If you are researching letrozole, comparing 2.5 mg Femara-style products or looking to buy Letrobol online from a verified Evolve Biolabs supplier, this page gives you the full specification, pack size, price and live stock status. Browse more Evolve Biolabs hormone-support products at NotNatty.