Femara vs. Clomid (Letrozole) – Finding the Best Choice for You

by May 12, 2021

Femara and Clomid are well known fertility drugs that are often prescribed as the first line of defense in many fertility treatments.  Depending on your diagnosis, your doctor may prescribe one over the other and understanding the difference between the two is key.

fertility drugs

Often used in situations where ovulation is an issue, it’s important to understand how Femara or Clomid could help you on your fertility journey.  Of course knowing your ovulation patterns and history can help set you up for a well-informed conversation with your doctor.

Read on for information on how fertility drugs like Femara and Clomid work, possible side effects, as well as outcomes and other factors to consider.  Ultimately only you and your healthcare team can make the decision of which one is right for you, but it doesn’t hurt to have a little information on your side!

Understanding Estrogen Manipulation

Both Femara and Clomid are specifically designed for women who have trouble ovulating.  They work by tricking the brain into thinking there’s less estrogen floating around in your system which in turn triggers your FSH (follicle stimulating hormone) levels to increase thereby making you ovulate.  Because estrogen powers the menstrual cycle and plays a key role in ovulation, too much estrogen can wreak havoc on your cycle and overall health in addition to impacting your fertility.

Estrogen is essential for conception for a number of reasons.  In the first half of your cycle, levels rise while your uterine lining is being rebuilt from your last period.  Estrogen’s influence on the cervix also facilitates conception through helping the cervix to open as well as contracting the uterus near ovulation to help move sperm in the right direction.

By signaling the pituitary gland when the egg is mature and ready to be released, estrogen indirectly triggers ovulation, as well as making sure conditions are ideal for implantation.  In other words, estrogen creates the perfect conditions for a possible pregnancy!

Since your hormones play such a vital role in regulating your body, if estrogen is too high it can have noticeable effects on both your overall health and fertility.  If you aren’t ovulating regularly, or your hormone levels are not ideal, you may be prescribed an estrogen manipulating drug like Femara or Clomid in your fertility treatment.  While this therapy can be a life-changing treatment, there are many factors to consider whether it is right for you.

Getting to Know the Fertility Drugs

Fertility drugs are often the main treatment for women with ovulation disorders and serve to increase the chances of conceiving as well as carrying the baby to term.  By regulating or stimulating ovulation, drugs like Femara and Clomid attempt to restore fertility and increase your chances of getting pregnant.


How Does Femara Work?

Femara, also known as Letrozole, is a type of drug known as an aromatase inhibitor.  Drugs in this class work by interfering with the body’s ability to produce estrogen from androgens, thereby lowering the amount of circulating estrogen in the body.

It works in a similar fashion to Clomid in that it stimulates ovulation but it does so by inhibiting aromatase and suppressing estrogen production.  In other words, Femara works by promoting the growth and release of eggs in women who have issues with ovulation.  Initially developed as a treatment for breast cancer, it has been increasingly used to treat infertility with promising results.

How Does Clomid Work?

Clomid, or Clomiphene Citrate as it’s known generically, works in a similar fashion to Femara in that it is used to trigger ovulation in women who either do not ovulate naturally or have unexplained infertility.

Clomid works by blocking estrogen receptors which then causes the pituitary gland to produce more hormones like FSH (follicle stimulating hormone) and LH (luteinizing hormone) to trigger follicle development and ovulation.

Essentially, Clomid tricks your body into thinking your estrogen levels are lower than they really are, which in turn causes the body to increase secretion of the hormones that trigger ovulation.

Comparing Femara vs. Clomid

It goes without saying that any medication decisions should be made by you and your healthcare team, but knowing how these two drugs work, and why you might choose one over the other is an important factor as well.  Although they both function similarly, there are differences to consider between Femara and Clomid like side effects, cost, and ultimately success rates.

Femara vs. Clomid: Side Effects

Side effects are an unfortunate reality to many drugs.  Common mild side effects with fertility drugs include hot flashes, headaches, nausea, and weight gain and Femara and Clomid are no different in this regard.

Women using Clomid report experiencing:

  • Bloating
  • Nausea
  • Headache
  • Mood swings
  • Vaginal dryness
  • Hot flashes.

Women on Femara report mild side effects such as:

  • Hot flashes
  • Flushed skin
  • Increased sweating
  • Swelling or joint pain
  • Headache
  • Dizziness.

Less common side effects for Femara include fatigue, nausea, and mood changes.

Occasionally, more serious side effects from both Clomid and Femara can occur, but they are uncommon.  For Femara this could mean weakened bones, increased cholesterol levels or a severe allergic reaction.  While for Clomid more serious side effects include ovarian cysts, seizures, stroke, or chest pain.   Serious side effects should never be ignored and you should consult with your doctor or medical emergency personnel immediately if you are experiencing a serious concern.

Femara vs. Clomid: Successes & Results

Studies show that pregnancy success rates for both Clomid and Femara are quite comparable.  Clomid helps between 70-80% of women ovulate and your chances of getting pregnant are approximately 30%.  Clomid is usually used for 6 cycles or less so if you haven’t conceived within six months, you might move onto another treatment.  It works well in the right circumstances, but other factors like age, low estrogen levels, or obesity all play a role in the drug’s efficacy for your treatment.

Although pregnancy rates between Clomid and Femara are quite similar, studies show that for women trying to get pregnancy with PCOS, the success rate of Femara is higher than Clomid. Even though the drugs have similar ovulation success rates, individual circumstances really do matter, and in the case of PCOS, Femara seems to work better.

Overall success rates depend on a number of factors though, such as your age, the condition of your reproductive organs, as well as sperm quality so it’s important to consider the success rate among people with your diagnosis.

Femara vs. Clomid: Cost & Availability

The cost and availability of these drugs may be a major consideration to factor into your decision.  Insurance policies and health benefits vary widely on their coverage of infertility treatment and your underlying medical issues will be a significant factor.

Both Femara and Clomid are widely available and comparable in price, although that will depend on your extended health coverage and benefits, as well as your location.

Is One Better Than the Other?

Femara and Clomid are both estrogen manipulating drugs that are used in the treatment of infertility.  When comparing the two, there are a number of individual factors that will ultimately determine which one is right for you.  Your fertility diagnosis, health conditions, and any other medications you may be taking will all contribute significantly to the decision to use one over the other.

Ultimately, both drugs help women conceive and one might be better suited for your situation.  Together with your healthcare team you can use this information to make an informed decision.

✔️ Medically Reviewed by Banafsheh Kashani, MD, FACOG

Banafsheh Kashani, MD, FACOGBanafsheh Kashani, M.D., FACOG is a board-certified OB/GYN and specialist in reproductive endocrinology and infertility at Eden Fertility Centers, and has been treatingcouples and individuals with infertility since 2014.

Dr. Kashani has conducted extensive research in female reproduction, with a specific focus on the endometrium and implantation.

Additionally, Dr. Kashani has authored papers in the areas of fertility preservation, and fertility in women with PCOS and Turners syndrome. She also was part of a large SART-CORS study evaluating the trend in frozen embryo transfers and success rates.

Order Your Mira Plus Today

Track your whole cycle and what is happening with your hormones. Get a larger fertile window (6 days) and clear insights. Let Mira take the guesswork out of tracking all fertile days and infertile days.