Is letrozole the same as the injectable stimulation medicines?

No, it is a tablet that works differently, and is typically used in milder stimulation or ovulation induction approaches rather than standard injectable IVF stimulation.

Does it need monitoring like other stimulation medicines?

Yes, your clinic will usually monitor the response with ultrasound scans, even though it is taken as a tablet.

What if a dose is missed?

Contact your clinic for advice rather than taking an extra dose or skipping ahead.

Can it be combined with injectable medicines?

Some protocols combine letrozole with low doses of injectable medicines. Only follow the specific combination your clinic has prescribed.

Oral aromatase inhibitor, used for ovulation induction or mild stimulation

Letrozole

Also known as Femara

Written by Zayn Miah & R KhanomLast updated 17 September 2026Not clinically reviewed

Letrozole is a tablet that works by reducing oestrogen production, which in turn encourages the body to release more of its own follicle stimulating hormone.

Why it may be used

It is used to encourage the ovaries to develop one or more follicles, and is used in ovulation induction cycles and in some mild or minimal stimulation IVF approaches rather than the higher dose injectable protocols.

Where it fits in a cycle

It is generally taken early in a cycle, over a short course of days, with the response checked by ultrasound scan. It is used differently from the injectable FSH medicines and forms part of milder stimulation protocols where a clinic has recommended this approach.

Side effects listed in the patient leaflet

Hot flushes
Headache
Fatigue
Nausea
Dizziness
Joint or muscle aches
Mood changes

When to ring the clinic

•Severe abdominal or pelvic pain
•Visual disturbances that are new or worsening
•Signs of an allergic reaction, such as rash or swelling
•Abnormal or heavy vaginal bleeding
•Any symptoms that concern you during a monitored cycle

Questions people ask

Is letrozole the same as the injectable stimulation medicines?: No, it is a tablet that works differently, and is typically used in milder stimulation or ovulation induction approaches rather than standard injectable IVF stimulation.
Does it need monitoring like other stimulation medicines?: Yes, your clinic will usually monitor the response with ultrasound scans, even though it is taken as a tablet.
What if a dose is missed?: Contact your clinic for advice rather than taking an extra dose or skipping ahead.
Can it be combined with injectable medicines?: Some protocols combine letrozole with low doses of injectable medicines. Only follow the specific combination your clinic has prescribed.

Safety

This page is general information only and does not replace advice from your fertility clinic.
The dose, timing and duration should come from your own clinic's written instructions.
The patient information leaflet in the box is the authoritative source for this medicine.
Tell your clinic about other medicines, allergies and medical conditions before starting.

Sources

Patient information leaflets and product characteristics, electronic medicines compendium (emc). Link checked 17 September 2026.
IVF: what is IVF and how does it work?, HFEA (UK fertility regulator). Link checked 17 September 2026.

Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.