Letrozole is a prescription aromatase inhibitor used to induce ovulation in women with PCOS who are trying to conceive.

How it works

Letrozole belongs to a group of medicines called aromatase inhibitors. It briefly lowers estrogen production. When estrogen levels dip for a short time, the brain responds by raising the hormones that stimulate the ovaries. This action can help a follicle mature and an egg be released. That is why the medicine is sometimes discussed in the context of ovulation for women whose ovulation is irregular. The process is overseen by a doctor so that the body’s response can be monitored carefully.

Many women with PCOS have irregular ovulation, which can make conceiving harder. When a woman with PCOS is trying to conceive but is not ovulating regularly, a doctor may discuss letrozole as one option, after assessing her overall health. It is usually taken for a few days early in the menstrual cycle, and the body’s response is monitored by the doctor. This monitoring matters to help make sure the medicine is having the intended effect safely. You can read more on the PCOS fertility and PCOS symptoms pages.

Why it is prescription only

Letrozole is a prescription medicine that can only be prescribed and monitored by a doctor, usually a gynaecologist. It should never be started on your own without medical advice, and it is not something to buy online for self-use. This is because suitability, dose, and cycle response need to be assessed and adjusted to each person’s situation. The medicine can also cause side effects or interact with other health conditions. Letrozole is used in other conditions such as breast cancer too, but fertility use requires medical assessment first, because the purpose and monitoring are different.

What it means for you

If you have PCOS and are planning a pregnancy, letrozole is only one of several approaches that may be discussed. The best choice depends on your health, age, and preferences, as well as the results of other checks. It is worth talking to a doctor or pharmacist before taking any fertility medicine, so you understand the benefits, risks, and monitoring involved. For the basics, see also what is PCOS.

This glossary is education, not diagnosis. For your own situation, ask a doctor or pharmacist.