Clomiphene: What It Is, How It Works, and What You Need to Know

When it comes to fertility, clomiphene, a selective estrogen receptor modulator used to stimulate ovulation in women with infertility. Also known as Clomid, it's one of the most prescribed medications for women who don't ovulate regularly. Unlike hormones like FSH or LH injections, clomiphene works by tricking your brain into thinking estrogen levels are low—this triggers the pituitary gland to release more follicle-stimulating hormone (FSH), which then tells your ovaries to produce and release an egg. It’s not a hormone itself, but a signal booster for your body’s own fertility system.

Clomiphene is most often used for infertility, the inability to conceive after 12 months of regular unprotected sex caused by ovulation disorders, conditions where the ovaries don’t release eggs on a regular cycle. Polycystic ovary syndrome (PCOS) is the top reason women turn to clomiphene—it helps restart ovulation in up to 80% of cases. But it’s not just for PCOS. Women with unexplained infertility, irregular periods, or even those with normal cycles but no ovulation detected may benefit. It’s not a magic pill, though. Success depends on timing, dosage, and whether other factors like sperm quality or tubal health are in check.

Clomiphene is usually taken for five days early in the menstrual cycle—days 3 to 7 or 5 to 9—and ovulation typically happens 5 to 10 days after the last pill. Doctors often pair it with ovulation predictor kits or ultrasound monitoring to time intercourse or IUI correctly. Side effects are usually mild: hot flashes, mood swings, bloating, or blurred vision. A small percentage of users may develop ovarian cysts or have a higher chance of twins—around 10%. It’s not meant for long-term use; most doctors limit treatment to six cycles because effectiveness drops after that.

There are alternatives, like letrozole (Femara), which studies show can be more effective than clomiphene for women with PCOS, especially when it comes to live birth rates. But clomiphene remains popular because it’s cheaper, widely available, and has decades of real-world use behind it. If you’ve been trying to get pregnant without success and your doctor says you’re not ovulating, clomiphene is likely one of the first options you’ll hear about—and for good reason.

Below, you’ll find real-world comparisons, patient experiences, and science-backed insights on how clomiphene stacks up against other treatments, what to expect during treatment, and how to maximize your chances of success—all written for people who want clear answers, not jargon.