When it comes to fertility medications, the first one that comes to mind is probably Clomid. However, there’s a variety of other drugs doctors prescribe to help you get pregnant. One you may not have heard of is letrozole.
Letrozole is a breast cancer drug but is commonly used off-label to induce ovulation. Research shows that it’s as effective—sometimes more effective—than Clomid.
In this guide, we’re discussing letrozole fertility drug. You’ll learn how it works, its effectiveness, side effects and how it compares to Clomid.
What Is Letrozole Fertility Medication?
Letrozole fertility medication (AKA Femara) is an oral drug used off-label to induce ovulation, aiding conception.
Although the Food and Drug Administration (FDA) has approved letrozole for postmenopausal breast cancer patients, it’s not officially approved for fertility. Despite this, the drug has been used for over 20 years to include ovulation. Research shows it appears safe and can be as effective as Clomid for some.
If your infertility is caused by ovulation problems—like polycystic ovary syndrome (PCOS)—your doctor may prescribe letrozole. By taking the drug, you’ll induce ovulation, opening up your window to successfully conceive. When taking the medication, your doctor will recommend the best days for intercourse (usually before and during the first days of your induced ovulation).
Letrozole fertility medication may also be used in cases of unexplained infertility. For women who ovulate naturally, it can help release multiple eggs, boosting the likelihood of fertilization.
Femara may also be prescribed to those who are Clomid-resistant. If Clomid doesn’t induce ovulation, Femara may do the job.
In some cases, a doctor may prescribe both letrozole and another fertility drug, like Clomid or injectables for in vitro fertilization (IVF).
Compared to other fertility treatments, letrozole is more accessible and less expensive than injectables. It’s also well-tolerated.
How Does Letrozole for Fertility Work?
Letrozole is taken for about 5 days nearing the beginning of your menstrual cycle. Your doctor will give you directions depending on your cycle, so make sure to follow them specifically.
In general, here’s how letrozole fertility medication works:
- Letrozole is taken daily on the cycle days directed by your doctor (ex. cycle days 3-7)
- Medication encourages the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- FSH and LH cause an egg to mature and be released (ovulation). If you already ovulate, multiple eggs may be released.
- Have intercourse on the specific days as directed, undergo IVF egg collection, etc.
Typically, you’ll start at a dose of 2.5 mg. If your doctor recommends a higher dose, you may be prescribed tablets of up to 7.5 mg.
Effectiveness of Letrozole Fertility Medication
How effective is letrozole fertility medication? The answer depends on a few factors, including:
- Age
- Condition/infertility cause
- Possible combined treatments (ex. taking letrozole with Clomid or letrozole using IVF)
As with any pregnancy, the success rates decline with age. In general, letrozole has been shown to be effective for those with and without PCOS. It can increase the chances of a successful pregnancy whether you’re hoping to conceive naturally or with assistance.
Research suggests that letrozole induces ovulation in 70 to 84% of people. According to a 2014 study, 27.5% of patients with PCOS got pregnant and successfully birthed their babies after using letrozole. Authors concluded that the ovulation rate was significantly higher during each monthly visit using letrozole compared to Clomid.
Research also shows that letrozole may help those undergoing IVF. A 2020 study found that combining letrozole with injectables improves ovarian response and IVF outcomes.
How Many Cycles of Letrozole To Get Pregnant?
One of the most pressing questions about the medication is how many cycles of letrozole does it take to get pregnant?
The number of cycles you’ll need to take a fertility medication before getting pregnant is individual. Some people successfully conceive the first or second cycle, while others may need to try another treatment altogether.
In the finding discussed above, 27.5% got pregnant within 5 cycles using letrozole. The average length of time to get pregnant was about 3 cycles. Your doctor may also increase your dosage after unsuccessful cycles.
If you don’t conceive within 5 cycles, you may talk to your healthcare provider about when to stop trying using that medication. How many cycles you go through may depend on your infertility condition, side effects experienced, and cost of the drug or health insurance coverage.
In cases when increased doses of letrozole aren’t effective, your doctor can recommend other treatments. This may include switching to another oral fertility drug or combining it with letrozole. Injectable medications to induce ovulation can also be considered. Other forms of treatment, like IVF and intrauterine insemination (IUI), may also be recommended.
Side Effects of Letrozole for Fertility
Those worried about negative reactions to fertility drugs may try Femara. According to research, letrozole has fewer side effects.
Side effects of letrozole for fertility include:
- Headaches
- Hot flashes
- Bloating
- Abdominal pain
- Cramps
When considering letrozole vs Clomid, one possible benefit is that some reports suggest letrozole doesn’t cause mood swings like Clomid. (However, some people still report having mood swings while taking letrozole fertility medication, so be sure to talk to your doctor)
You might also wonder if letrozole can affect your baby if you successfully conceive. Early research suggested letrozole might be linked to abnormal fetal development. However, several higher quality and more recent studies prove otherwise. When compared with Clomid or the general population, letrozole did not have a higher rate of abnormalities and negative outcomes. Some researchers also suggest letrozole is safe for the baby because the drug is typically eliminated from the body before implantation.
If you’re researching side effects of letrozole for fertility, it’s important to note that reactions may differ if it’s taken for breast cancer. In breast cancer patients, it’s used post menopause and taken for a much longer period of time. For example, breast cancer patients may experience letrozole side effects like arthritis and arthralgia.
Letrozole should not be taken if there’s a chance you’re already pregnant. It may also be unsafe during breastfeeding.
Letrozole vs. Clomid
You might be wondering if letrozole vs Clomid is more effective. That answer may depend on the reason for your infertility.
Research suggests that letrozole may be more effective than Clomid for women with PCOS. In the study discussed above, pregnancy and live births occurred for 27.5% of patients with PCOS. This is compared to 19.1% of those who got pregnant using Clomid.
According to the Canadian Fertility and Andrology Society, letrozole is more effective than Clomid for achieving live births in patients with ovulatory disorders. For this reason, letrozole is often the first choice for those with PCOS.
If you don’t have an ovulatory disorder, research suggests letrozole is as effective as Clomid, so your doctor may prescribe one or the other.
In some cases, your doctor won’t choose between letrozole vs Clomid; they’ll prescribe both. A 2019 study showed that women who had a combination of letrozole and Clomid had a higher ovulation rate than those who took letrozole alone.
Summary: Letrozole Fertility Medication
Letrozole fertility medication is used off-label to induce ovulation, increasing your odds of getting pregnant and having a baby. Although the FDA has only approved the medication for breast cancer, it has been safely used for over 2 decades to help conception. Femara is typically taken for a specific window of 5 days. This will encourage hormones to release, releasing the egg and starting ovulation. Your doctor will recommend specific days to have intercourse for your best chances (usually before and on the first days of ovulation).
Compared to the popular fertility medication Clomid, letrozole is as effective or more effective. Those with PCOS are often recommended letrozole as the first line of treatment. The drug may also be combined with Clomid or other fertility treatments. Letrozole fertility medication is well-tolerated with fewer side effects, making it a suitable option for those who have experienced reactions to similar drugs.
Although around 28% of women conceive and successfully birth a baby using letrozole, it doesn’t work for everyone. If you aren’t pregnant through multiple cycles, your doctor may increase your dosage or recommend another medication. You may also consider other forms of assistance, like IVF and IUI.
P.S. When you successfully conceive, hear the magic of your baby’s heartbeat at home! A pocket fetal doppler is a handheld device that you can use to detect your baby’s heartbeat from home. It’s easy to use and brings a bonding experience to the entire family! Couples who’ve had miscarriages find the fetal doppler especially reassuring. It can help calm anxious nerves over your baby’s health between appointments.