How It Works
Clomiphene stimulates the release of
hormones needed to cause
Clomiphene therapy is
typically used for 5 consecutive days early in the
menstrual cycle, for 3 to 6 monthly cycles. It may
take several cycles to find the right dose to stimulate ovulation. After that
dose is determined, a woman will take the drug for at least 3 more cycles. If
she does not become pregnant after 6 cycles, it is unlikely that further
clomiphene treatment will be successful.
Why It Is Used
Clomiphene may be prescribed to:
- Stimulate ovulation in a woman who does not
ovulate or who ovulates irregularly. Her
estrogen levels and
pituitary gland function must be normal, and her male
partner must be diagnosed as fertile.
- Perform a clomiphene challenge test, which is sometimes used to evaluate
a woman's ovulation and egg quality (ovarian reserve). When given early in a
woman's menstrual cycle for 5 days, clomiphene elevates a woman's
follicle-stimulating hormone (FSH) level. On the next day, an FSH blood level
that has dropped back to normal is a sign of a normal ovarian reserve and
ovulation. An elevated FSH is a sign of low ovarian reserve. Women who have a
diminished ovarian reserve can use donor eggs, which greatly improves their
chances of giving birth to a healthy child.
- Stimulate the
development of multiple eggs for use with
assisted reproductive technology, such as in vitro
fertilization (IVF) or gamete intrafallopian transfer
- Regulate ovulation in a woman who ovulates irregularly
and/or is going to have
intrauterine insemination or artificial insemination.
Clomiphene is sometimes used together with other medicines
and infertility treatments.
Before trying clomiphene, women with
polycystic ovary syndrome (PCOS) who are overweight
are advised to lower their
body mass index (BMI) with diet and exercise. Reaching
a healthy weight can restart ovulation. If that isn't
successful, using medicine to correct
insulin metabolism may start ovulation. If not, a
combination of medicines may help stimulate ovulation.
For men. Clomiphene may be used to treat low sperm counts
How Well It Works
Unexplained infertility. There is limited evidence that clomiphene makes pregnancy
more likely for couples with unexplained infertility.1
Clomiphene may be most effective when it is used to generate multiple eggs
before an insemination procedure.
Infrequent or no ovulation. Of women whose infertility is caused only by absent or
infrequent ovulation, with clomiphene treatment approximately 80 out of 100 women will ovulate.
And within 9 cycles of treatment, 70 to 75 out of 100 will become pregnant. Experts used
to think miscarriage rates were slightly higher in women who became pregnant
using clomiphene. But recent studies have not shown this to be true.2
Polycystic ovary syndrome. Clomiphene alone may not be an effective treatment for most
women with polycystic ovary syndrome (PCOS) and severe
insulin resistance, which is closely linked to
obesity. Women with PCOS who are overweight often begin ovulating when they
reduce their body mass index (BMI) with diet and exercise.
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
Call your doctor if you have:
Common side effects of this medicine include:
See Drug Reference
for a full list of side effects. (Drug Reference is not available in all
What To Think About
In some studies,
miscarriage rates are slightly higher in women who
become pregnant using clomiphene. It is not clear if this is related to an
early hormonal effect on the egg or to preexisting conditions such as age or
polycystic ovary syndrome, which are found more often in women who take
clomiphene. Other studies have not shown an increased miscarriage rate.2
Of women who become pregnant after clomiphene therapy, about 7 to 10 out of 100 have a multiple pregnancy. Multiples resulting from clomiphene
treatment are usually twins. Triplets are rare.2
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
When you know you are pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant or trying to get pregnant.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Bhattacharya S, et al. (2010). Female infertility, search date
October 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Fritz MA, Speroff L (2011). Induction of ovulation. In
Clinical Gynecologic Endocrinology and Infertility, 8th
ed., pp. 1293–1330. Philadelphia: Lippincott Williams and Wilkins.
Primary Medical Reviewer
||Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer
||Femi Olatunbosun, MB, FRCSC - Obstetrics and Gynecology
Current as of
||November 14, 2013