First approved by the FDA in 1997, Letrozole, also known under the trade name Femara, was originally developed as a breast cancer treatment. However, since 2001 it has also been used as a fertility drug. Recently, scientists examined the efficacy of Letrozole for infertility treatment compared to natural and HRT cycles as well as other drugs.
Letrozole is an aromatase inhibitor, which suppresses the enzyme that produces estrogen. A Japanese study recently published in Human Reproduction journal reviewed data from more than 110 thousand treatment cycles, and found that patients treated with the drug had significantly higher clinical pregnancy and live birth rates, and significantly lower miscarriage rates compared to patients who underwent HRT or natural cycles following a frozen-thawed embryo transfer.
These findings come on the back of another study, published in the same journal just months earlier, that showed that pregnancy rates were higher for women with PCOS who were treated with Letrozole compared to Clomiphene Citrate (another fertility medicine); they also needed fewer cycles to conceive. This is also in line with data presented during a 2013 ASRM meeting that showed almost 1.5 times higher live birth rates for patients on Letrozole than on Clomid.
Another known advantage of the drug is how fast it cleared from the body. While patients who received Clomiphene may experience uterine lining and cervical mucous irregularities for up to 8 weeks after they’ve stopped taking it, those who received Letrozole for infertility treatment is unlikely to suffer from this type of side effects as the medication clears quickly from the body.