Ovulation Induction

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Letrozole Treatment

The leaflet is detailed below, or you can download the 'Letrozole Treatment' leaflet in PDF.

What is Letrozole?

Letrozole (Femara) is a medication approved for the treatment of breast cancer. It is an aromatase inhibitor and works by lowering the production of oestrogen. Letrozole has also been shown to be effective at inducing ovulation in infertility patients. Treatment may increase the chance of a twin pregnancy, although this is much less than with Clomiphene (Clomid), where the risk can be increased four-fold.

What are the benefits of Letrozole treatment?

The benefits of taking Letrozole tablets are to encourage or regulate ovulation to achieve a pregnancy. The half-life of Letrozole is very short (2 days) compared to Clomiphene. This means the medication is metabolized more rapidly and the side effects are less. Letrozole does not affect the cervical mucus or endometrial (womb) lining as much as Clomiphene. This is better for sperm transport in the cervix and a more favourable lining for implantation.

Are there any alternatives to Letrozole treatment?

Alternatives to Letrozole tablets include Clomiphene tablets and gonadotrophin injections.

Risks and adverse effects

Risks of Letrozole treatment include ovarian hyperstimulation syndrome which is a condition caused by the over-production of eggs and can be very serious. There is also an increased risk of having a multiple pregnancy (approximately double the risk).

Common adverse effects include hot flushes, nausea, headaches, bloating, muscle aches, blurred vision and fatigue. These adverse effects occur in approximately 10 to 20% of patients. If you experience problems with vision, abdominal pain, abdominal swelling or vomiting, the medication should be stopped and medical advice sought. If you have any other questions or worries, please feel free to ring your clinic and speak to a member of staff (see useful contacts below),

How Do I Take The Medication?

The starting dose is usually 2.5mgs a day from day 2 to day 6 of your menstrual cycle, day 1 being the first full day of bleeding during the menstrual period. You will be asked to either perform home urine ovulation tests or attend for a blood test on day 21 of that cycle to check your progesterone level. These hormone tests will inform us whether you have ovulated or not. Some patients with irregular periods may be asked to attend on different days of the cycle to try to determine whether ovulation has occurred. It may take several days for the progesterone result to be available. If ovulation has occurred and you are not pregnant, in the next cycle you should take the same dose of Letrozole.

Before starting Letrozole treatment the doctor or nurse will discuss the drugs with you. If you do not understand, or have any concerns, please contact your clinic for further advice. Most patients will ovulate following treatment with one or two tablets of Letrozole a day. Some patients may require higher doses and others may not ovulate at all. Under these circumstances alternative treatments will be discussed.

Once ovulation has been confirmed it is usual to continue on the same dose for up to six cycles. If a pregnancy has not occurred after six ovulatory cycles you will be asked to see the Consultant.

Useful contacts

If you are a patient of the Liverpool Hewitt Fertility Centre you can contact the nursing staff Monday to Friday 08.00 – 16.45, Saturdays 08.15-13.15 via 0151 702 4123 Option 1.

If you are a patient of the Knutsford Hewitt Fertility Centre you can contact the nursing staff Monday to Friday 08.00 – Saturdays 01565 653 287.

If you are attending the Gynaecology out-patient department on the ground floor of Liverpool Women’s  Hospital you can contact the nursing staff Monday – Friday 09.00 – 17.00 via 0151 708 9988.

Please note that the Liverpool Women’s NHS Foundation Trust is a smoke free site. Smoking is not permitted inside the hospital building or within the hospital grounds, car parks and gardens. Staff are available to give advice about stopping smoking, please ask about this.