What is Clomid?

Clomiphene (best known by the brand names Clomid or Serophene) is an oral fertility medication used to induce ovulation in women who have trouble ovulating in order to help them get pregnant. The most important thing to know is that Clomid is a medication to induce ovulation, not necessarily pregnancy.

Clomid will not get you pregnant by itself. All that it is supposed to do (and it doesn't do it all the time) is make you ovulate. Obviously, you can only get pregnant if you first ovulate. 

How does Clomid work?

Clomid is a synthetic chemical which induces ovulation by fooling your body into believing that there is less estrogen. This leads to an increased production of a hormone called GnRH, causing the pituitary to pump out more of another hormone called FSH and LH, thus inducing ovulation.

Clomid is very powerful and induces ovulation in over 50% of all women who take it. Clomid works well for many women but it does come with side effects like headaches, mood swings, hot flashes, weight gain, etc. It is usually given as a pill once a day for 5 days. The typical starting dosage of Clomid is 50 mg/day for 5 days, and it can be increased monthly by 50 mg a day. The first pill of Clomid is usually started 2 to 5 days after the first day of your menstrual bleeding (cycle day 2-5) and ovulation usually happens 5-9 days after the last dose of Clomid.

If you don’t bleed, and after pregnancy has been excluded, bleeding can be started by taking progesterone.

How successful is Clomid in polycystic ovary syndrome (PCOS)?

Your chances of getting pregnant with Clomid are very good as long as you take it for the right reasons and have some tests done beforehand to exclude certain problems. The majority of women with polycystic ovarian syndrome who have an adequate ovarian reserve, a partner with good sperm count, a healthy body weight and open fallopian tubes will be able to have a baby with Clomid treatment.

What is the success rate when using Clomid for PCOS and ovulation?

About three-fourths of women with PCOS that are not ovulating will ovulate on Clomid at some dosing level. Women under 35 with PCOS should have about a 15% chance for pregnancy per month with Clomid treatment (for about 3-4 months) if they ovulate with Clomid (assuming the sperm and fallopian tubes are normal).

What is the success rate for getting pregnant with PCOS when using Clomid?

About 50% of women that ovulate with Clomid get pregnant with it. But it also depends on a woman's age and other factors. In-vitro fertilization may improve pregnancy chances. For women with PCOS under age 35, the success rate of IVF is about 70% for pregnancy with one IVF cycle and about 60% for live birth. No matter how well Clomid works to help you ovulate, you will have difficulty getting pregnant unless there are good quality eggs, healthy sperm, open fallopian tubes, and an optimal weight.

How does Clomid affect twins and multiples?

Clomid causes twins in about 10% of pregnancies. Less than 1% of Clomid pregnancies lead to triplets or higher order pregnancies.
Most twins conceived with Clomid will be "dizygotic" twins, or non-identical. That is because Clomid leads to multiple ovulations, and non-identical twins are twins resulting from separate eggs and fertilization with different sperm, while identical (or monozygotic twins) result from the splitting of a single fertilized identical egg and sperm. 

How does Clomid affect an ovulation predictor kit (OPK)?

Some women take Clomid and use ovulation predictor kits to time intercourse with ovulation. Many doctors will monitor you using ultrasound equipment and blood work to tell you the best time to try to conceive.

Ovulation prediction kits are sensitive to the luteinizing hormone (LH). While most medications will have no effect on the test results, there is a certain sector of medications that can have a very real effect. These medications are often prescribed for infertility. If a woman is not producing enough LH she may not be able to conceive. For this reason, some infertility medications contain LH to improve the chances of fertility.

Can Clomid cause false positive OPK results?

Several infertility medications can cause the ovulation kit to test falsely positive. These include Clomid, Pergonal, Humegon, and Repronex. Clomid can cause an ovulation prediction kit to test positive even when the woman is not ovulating. According to the manufacturer of Clomid, three days should pass between the last day taking the Clomid and the first day testing for ovulation. For instance, if the medication is taken for 10 days, it is okay to start using the ovulation prediction kit on the 14th day.

Does Clomid cause ovulation all the time?

Like all fertility treatments, there are no guarantees. Even if you do ovulate while on Clomid, you still need the egg and sperm to meet for fertilization to occur and then implantation. Some women try it for 2 or 3 or more months/cycles. Some women will become pregnant and others will move onto other treatments.

Tests Before Starting Clomid

Before taking Clomid you should have some tests done to make sure you take it for the right reasons. 

TIP: Do a sperm count before starting Clomid. It makes no sense taking Clomid when he has a low sperm count!

Before giving Clomid, patients should be checked to make sure she is:

  • not pregnant
  • has no ovarian cysts (except if there is polycystic ovary syndrome)
  • has no abnormal uterine bleeding (if there is abnormal bleeding a tumor should be ruled out)
  • has no fibroids
  • has no abnormal liver function (do a liver blood test).

The following tests should be done before Clomid is given:

  • Pregnancy test
  • Sperm count
  • Estrogen levels
  • CD 3 FSH levels
  • Thyroid function tests
  • Prolactin levels
  • Liver function tests
  • Endometrial biopsy





Ovulation test No ovulation Zero chances getting pregnant unless you take medication like Clomid to induce ovulation
Sperm Count He has not enough sperms Clomid will not improve the chances of getting pregnant. You should improve his sperm count first.
Fallopian tube patency Both fallopian tubes are closed Zero chances getting pregnant, even with Clomid. Surgery to open the tubes or in-vitro fertilization (IVF) will help you get pregnant.
Bad quality of eggs Test shows severely elevated FSH Clomid unlikely to improve pregnancy chances. In-vitro fertilization (IVF) will help you get pregnant.

How do you know that Clomid worked?

So how do you know that Clomid has worked? If you ovulated while on Clomid, that means it worked. If you did not ovulate, it did not work. Yes, it's that simple. 

How long does it take to ovulate using Clomid?

For women that do not ovulate on their own, the average day that ovulation occurs is about 8 to 10 days after completing a 5-day course of Clomid.

  • That means that a woman taking Clomid on days 5-9 will often ovulate on about day 16-20 of the cycle
  • However, there is significant variation in how long it takes ovulate using Clomid. Some will ovulate much later a— as late as two or three weeks after the last clomiphene tablet.

How can you find out if you did ovulate on Clomid?

There are several ways to find out if and when you ovulate:

  1. Ovulation Calculator
  2. Fertility Charting: BBT
  3. Cervical Mucus Changes
  4. Ovulation Pain: Mittelschmerz
  5. Progesterone Levels During Ovulation And Pregnancy

Read more about typical ovulation symptoms.

When should you increase Clomid?

Most doctors start Clomid at 50 mg a day for 5 days. If you do ovulate on Clomid, then there is no need to increase it in the next cycle. If you do NOT ovulate on Clomid, then your doctor often increases Clomid in the next cycle. Increasing Clomid when you are already ovulating on a lower dose is not only unnecessary, but it could, in fact, decrease your chances getting pregnant.

How long should you be on Clomid before moving on to other treatment options?

While there is generally no total number of cycles of Clomid that should be done before moving on to other fertility treatments, there are several variables involved in the decision about moving on to more aggressive therapy.

What does it mean when you have a missed menstrual period on Clomid and a negative pregnancy test?

If you take Clomid and your menstrual period has not come when you expected, then do a pregnancy test. A repeatedly negative pregnancy test after a missed period and Clomid usually means that you did not ovulate, Clomid did not work, and you are not pregnant. Here are three possible scenarios:

  1. You ovulate and did NOT get pregnant: Your menstrual period will arrive about 14 days after the day of ovulation.
  2. You ovulate and did get pregnant. Your menstrual bleeding, your period will not arrive 15+ days after the day of ovulation. Do a pregnancy test.
  3. You did NOT ovulate. If you don't ovulate then you will usually not bleed, you may not get any bleeding or it will be irregular. You may bleed or spot irregularly but it's not a menstrual period.  

Read More:
Clomid Ovulation Calculator