The Femara vs. Clomid Showdown: What's the Difference?

Sometimes, our bashful little human eggs need some help coming out of hiding. That's where a medication like Femara or clomid comes into play. But how can we differentiate between them? What's the deal with Femara vs. clomid?

"Both Femara and clomid fall in the general category of the 'anti-estrogen' family of drugs," says David Diaz, MD, reproductive endocrinologist at MemorialCare Orange Coast Medical Center in Fountain Valley, California.

Basically, Femara and clomid lower estrogen levels in the body. That, in turn, causes your FSH (follicle stimulating hormone) levels to increase. FSH (you guessed it) stimulates the development of egg-containing follicles. In other words, it makes you ovulate.

Who needs these meds, anyway?

Either Femara or clomid may be prescribed if ovulation test kits—confirmed by blood tests—indicate that you're not ovulating, or not ovulating regularly. They can also be used if you have unexplained infertility and in conjunction with IUI (intrauterine insemination).  

"Clomid is considered the 'gold standard' oral medication (often) used as the first line treatment to help women with infrequent or absent ovulation," says Dr. Diaz. Some conditions treated with Clomid include chronic anovulation and PCOS.  

The skinny on clomid (a.k.a. clomiphene citrate or Serophene)

Clomid goes by many names, but most of us have heard of it in one way or another. This common fertility drug has been around for 50 years and is basically a "false messenger," says Dr. Diaz. According to Dr. Diaz, clomid blocks estrogen receptors in the body, thereby tricking the pituitary gland to release FSH. This stimulates egg sac growth and, ultimately, ovulation.

Clomid: the good, the bad and the ugly

Here's how taking clomid works: It's a 50 mg pill that you usually start taking on the third, fourth or fifth day of your menstrual cycle. In most cases, about seven days after you take the last pill, you should ovulate. Time for that super-sexy planned intercourse or IUI.

The thing about clomid, though, is that it can work, but it can also cause side effects. Some of these are minor and similar to what you'd experience when you're getting your period, including:

• Bloating
• Vaginal dryness
• Sore breasts
• Upset stomach
• Headaches
• Hot flashes
• Moodiness
• Dizziness
• Thinned uterine lining

And there are also some more concerning potential side effects to watch out for and let your doctor know if you experience, including:

• Abnormal bleeding
• Blurred vision and other vision problems
• Yellow eyes and skin
• Depression
• Stomach or pelvic pain

If your infertility is still unexplained at this point and you've taken 3-4 cycles of clomid, you should probably talk to your doctor about another course of action. If you're anovulatory, it's recommended you don't take clomid for more than 6 cycles.  

Femara (a.k.a. Letrozole): what's the sitch?

Femara (a brand name for a drug called letrozole) started out as a treatment for breast cancer in postmenopausal women. But doctors have discovered it can also help younger ("childbearing age") women ovulate.

It's all about lowering estrogen levels, says Dr. Diaz. "The drug functions by blocking aromatase, a necessary enzyme needed in the formation of estrogen," he says. Lowering estrogen can help knock out breast cancer in some women—and it can also help stimulate those egg follicles in TTC women.

While Femara is technically not FDA approved for infertility treatment, a 2014 New England Journal of Medicine-published study found femara (a.k.a. letrozole) to be more effective than clomid for women with polycystic ovary syndrome (PCOS) in trying to get pregnant. It's also often prescribed for patients undergoing IUI.

There are some other special situations in which letrozole may be prescribed over clomid. Per Dr. Diaz, letrozole in combination with injectable fertility drugs is the preferred IVF treatment for women diagnosed with breast cancer, or for women seeking to freeze their eggs before cancer therapy begins.

Also, letrozole doesn't linger in the body as long as clomid does, says Dr. Diaz. So as a result, it exhibits fewer side effects, although it isn't totally risk-free.  

Side effects can include:

• Fatigue
• Weight gain
• Headache
• Bone or muscle pain
• Hot flashes

A typical dose of letrozole is 2.5 mg, and it should be taken once a day for five days, usually beginning on day three of your period.

Femara vs. clomid: the face-off

In the battle of Femara vs. clomid, we can't tell you which one will work better for you. It will depend on your fertility diagnosis, other medications you're taking, and any other health conditions you may have.