What is Letrozole?

Letrozole is an established medication that is now being used to induce ovulation in women who are trying to get pregnant. Certain groups of women respond well to this medication, and it is increasingly used in the treatment of infertility. Below, we will explore, “What is Letrozole?”

What is Letrozole?

Letrozole is an aromatase inhibitor that has been used in women with breast cancer for a number of years. The drug inhibits aromatase, which in turns prevents the body from producing estrogen. This causes the body to produce increased amounts of follicle stimulating hormone (FSH) and luteinizing hormone (LH), both of which cause the ovaries to produce egg follicles.

Clomid or clomiphene, one of the most common drugs used to improve ovulation, also has the effect of increasing the amount of FSH and LH in the body. However, rather than reducing estrogen production, Clomid works by blocking estrogen receptors in the hypothalamus and the pituitary glands, so that the body thinks that there is less estrogen than there actually is.

Who is a Candidate?

Letrozole can be used to induce ovulation in women who are not ovulating at all (ovulation induction). It can also be used to cause what is known as superovulation in women who do ovulate sometimes but who still have not been able to get pregnant.

Letrozole is a strong option for women who have not responded to Clomid but who are not interested in using gonadotropins due to the cost, risks, or inconvenience associated with those drugs. It is an especially good option for women with polycystic ovarian syndrome (PCOS), who traditionally respond poorly to therapy with Clomid.

Only a doctor can determine whether or not you are a good candidate for Letrozole. This decision will be made based on the nature of your infertility, how you have responded to previous treatments, and your personal preferences.


Several studies have examined the effectiveness of Letrozole for producing ovulation in women with infertility. The majority of these studies, including the largest study conducted, found that Letrozole was effective for many women, including women with PCOS.

In a study of 750 women with PCOS who were randomized to receive either Letrozole or Clomid for up to 5 cycles, 61.7% of women who took Letrozole ovulated, and 27.5% had live births. The benefits were highest in obese women. For women with PCOS, the drug was found to be more effective than Clomid at producing ovulation and more likely to lead to live births.


As with any drug, there is some potential for side effects from Letrozole. However, because the drug does not stay for a long time in the body, any side effects that do develop are usually mild and short-lived. Letrozole is less likely than Clomid to have a negative effect on the cervical mucus or uterine lining.

Letrozole has been used for a number of years for breast cancer, and most studies on Letrozole side effects were done on women who were on the drug for an extended period to treat breast cancer. In contrast, using Letrozole for fertility treatment only requires 5 days of treatment.

The most common side effects are those associated with lower estrogen levels, including hot flashes, headaches, and breast tenderness. These side effects usually fade soon after the woman is no longer taking the medication.

Dr. Randy Morris would be happy to meet with you about whether or not Letrozole is right for you. To schedule your consultation today, please click below and enter your information or call IVF1 at (630) 357-6540.

Similar Posts