How does letrozole help with ovulation and pregnancy?
1 July 2025How does letrozole help with ovulation and pregnancy?
Letrozole, a medication originally developed to treat breast cancer, has found a remarkable new role in the world of fertility treatment. For many women who are struggling with ovulation issues or conditions like polycystic ovary syndrome (PCOS), Letrozole has become a safe and effective option to improve their chances of conceiving.
In this blog, I’ll share how Letrozole works, who can benefit from it, and what to expect during treatment.
What is letrozole?
Letrozole is an aromatase inhibitor, Invented to be used to treat hormone-sensitive breast cancer. It works by lowering estrogen levels in the body.
However the usefulness In fertility treatment was soon discovered. Initially there was apprehension of using anticancer drug for fertility. Now Letrozole is approved for use for fertility in many countries, including countries with stricter criteria for safety.
How does letrozole help with ovulation?
To understand Letrozole’s role in ovulation induction, here’s what happens inside the body:
- Reduction in estrogen levels – Letrozole blocks the enzyme aromatase, which is responsible for converting androgens into estrogen. This results in lower estrogen levels in the body.
- Stimulation of FSH production – The brain senses the drop in estrogen and signals the pituitary gland to release more follicle-stimulating hormone (FSH). Increased FSH promotes the growth and development of ovarian follicles.
- Triggering ovulation – As the follicles grow and mature, they release eggs—leading to ovulation, which is crucial for natural conception or assisted reproductive treatments like IUI or IVF.
Why is letrozole preferred for ovulation induction?
Letrozole is often favored over Clomiphene Citrate (Clomid) for certain reasons:
- Higher ovulation and pregnancy rates, especially in women with PCOS.
- Lower risk of multiple pregnancies compared to Clomid.
- Shorter half-life, meaning fewer side effects and faster drug clearance.
- No adverse effects on cervical mucus or endometrial lining, both important for implantation.
Who can benefit from letrozole?
Letrozole may be recommended for women with:
- Polycystic Ovary Syndrome (PCOS).
- Irregular or absent ovulation.
- Unexplained infertility.
- Previous unsuccessful ovulation induction with Clomid.
- Need for ovulation induction in IUI cycles.
How is letrozole taken?
Letrozole is usually prescribed as part of a controlled ovulation induction cycle.
Typical letrozole protocol:
- Dosage: 2.5 mg to 7.5 mg daily.
- Duration: Usually taken for 5 days, starting on Day 2 to Day 5 of the menstrual cycle.
- Monitoring: Follicle tracking through ultrasound to assess response.
- Trigger shot: An hCG injection may be given when the follicle matures to induce ovulation.
- Alternate Letrozole protocols: Many different protocols are in common use today like single dose , step up protocol or extended 8-10 days protocol etc.
Success rates with letrozole
Numerous studies show promising results:
- Ovulation success: 60-80% of women ovulate with Letrozole.
- Pregnancy rates: Approximately 20-27% per cycle in women with PCOS when ovulation is achieved. The pregnancy rates reduce gradually with each unsuccessful cycle.
- Live birth rates: Higher compared to Clomid in PCOS patients, as per large clinical trials.
Many women have experienced successful outcomes with Letrozole, both on its own and when combined with additional fertility treatments like IUI.
Possible side effects
Letrozole is generally well-tolerated, but like all medications, it may cause some side effects:
- Hot flashes.
- Headache
- Fatigue
- Mood swings.
- Mild nausea.
These symptoms are usually short-term and subside once the medication is stopped.
Is letrozole safe?
Yes, Letrozole has been widely studied and is considered safe for ovulation induction. It does not increase the risk of congenital abnormalities and is now recommended by many guidelines as a first-line treatment for ovulation induction in women with PCOS.
Conclusion
Letrozole offers a highly effective and well-tolerated option for women struggling with ovulation issues, particularly those diagnosed with PCOS. Its ability to gently stimulate the ovaries and encourage natural ovulation makes it a valuable treatment for women who have irregular or absent menstrual cycles. Unlike some other fertility medications, Letrozole has a lower risk of multiple pregnancies and does not negatively affect the endometrial lining or cervical mucus, both of which are crucial for conception. Whether used alone or in combination with treatments like IUI, Letrozole can significantly increase the chances of achieving a successful pregnancy. For individuals seeking a safe, affordable, and proven approach to overcome ovulatory infertility, Letrozole remains a trusted and effective option.
If you’re considering Letrozole as part of your fertility plan, contact Bavishi Fertility Institute today to speak with our expert team and take the next step toward parenthood.
Author bio
Dr. Parth Bavishi, MD in Obstetrics and Gynecology, brings over 12 years of invaluable work experience to his role as Director of Bavishi Fertility Institute, leading a group of IVF clinics committed to helping couples realise their dreams of parenthood.
Bavishi Fertility Institute is dedicated to providing customised and personalised treatments which are simple, safe , smart and successful. Bavishi Fertility Institute works with success and satisfaction for all at heart. Providing an ideal blend of professional treatment and personalised care.
Dr Parth had special training in infertility at Bavishi fertility Institute, the Diamond Institute, USA, and the HART Institute, Japan.
Dr. Bavishi is a distinguished expert in his field. In addition to his clinical practice, Dr. Bavishi is the author of the acclaimed book, ‘Your Miracle in Making: A Couple’s Guide to Pregnancy,’ offering invaluable insights to couples navigating the complexities of fertility. He loves to empower patients to make the correct choice by education both online and offline.
His exceptional contributions have earned him the prestigious Rose of Paracelsus award from the European Medical Association. Dr Parth has been an invited faculty at many national and international conferences.
Beyond his professional endeavors, Dr. Bavishi is an avid traveller who finds solace in exploring new destinations. He also enjoys engaging his mind with brainy puzzles, always seeking new challenges and solutions outside of the medical realm.
FAQs
Yes, in some cases, Letrozole is used to enhance ovulation quality or timing, even in women who already ovulate regularly but have not conceived.
While not its primary indication, Letrozole may still be considered in mild cases of diminished ovarian reserve, but results may vary.
Yes, it is sometimes combined with gonadotropins (injectable FSH) in more complex or resistant cases to enhance follicular development.
Most doctors recommend limiting Letrozole treatment to 4–6 cycles. If pregnancy doesn’t occur within this timeframe, alternative treatments are usually explored.
No, current evidence suggests that Letrozole does not harm long-term fertility or ovarian function when used under medical supervision.
If you miss a dose, take it as soon as you remember—unless it’s almost time for the next dose. Never double up without medical advice.
Ahmedabad