What is Progesterone?

Progesterone is a hormone that is only administered after ovulation has occurred (i.e., 4 days after an LH surge or HCG injection, two days after insemination is completed, or the evening following IVF egg retrieval).

How does Progesterone work?

Progesterone changes the lining of the uterus to make it more receptive for implantation and it is responsible for slightly raising the body temperature during the second half of a women’s menstrual cycle.

You will receive progesterone either in the form of an intramuscular injection or vaginally. Your dosage by injection (or vaginally) will be discussed with you. Some patients prefer injection while other patients prefer to avoid injection and can tolerate a vaginal medication. For those patients bothered by the messiness of suppositories, we suggest wearing a pad to absorb the discharge associated with the suppositories. If intercourse takes place, insert the suppository afterward.

You must continue your progesterone therapy until your pregnancy blood test result is known. And since progesterone may delay the onset of your period, a pregnancy test should be scheduled two weeks after ovulation, regardless of whether you have started bleeding.

Progesterone Injections

To support the lining of your uterus in IVF (fresh, FET, or recipient), you will be asked to take daily injections of Progesterone beginning the day after egg retrieval. You may give your injections at night before bedtime. It is important to be consistent with the timing. This type of progesterone is made from natural progesterone and is not thought to cause an increased risk of birth defects. However, the package insert lists abnormalities that have been associated with the use of synthetic (man-made) progesterones. Please do not let this alarm you; virtually all IVF programs use progesterone.

Side Effects

Occasionally, women will complain about an itchy discharge with vaginal progesterone use. It is also possible to develop a yeast infection while using this hormone. This is not a serious complication and it will not affect fertility. If you are bothered by increased discharge accompanied by an itch or raw feeling, then please let us know. In most cases this is not yeast, only irritation from the progesterone.

Progesterone therapy is a standard part of our fertility medication / insemination program, as well as our IVF and egg donation program. We have had many years experience using this medication and feel comfortable recommending it to you as part of your therapy.


The progesterone medication used in your prescription is similar to natural progesterone produced by your ovary. Please note that progesterone is related to a variety of hormones known as progestins (for example, Provera; or the progestin in the birth control pill). All progestins are required by law to have a package insert that describes some studies that suggest a slight increase in birth defects associated with its use.

Please note that all of these studies have involved synthetic or man-made progesterones and do not describe the progesterone that we use. There appears to be no increase in birth defects linked to the more natural progesterone (“progesterone” in oil or “progesterone” in suppositories) that we will prescribe for you at Carolina Conceptions. These studies also involved a higher dose, and were administered at a later time in the pregnancy.

Do patients really need progesterone with ovulation augmentation?

The luteal phase of the menstrual cycle is the two week period following ovulation. When couples use injectable gonadotropins (Follistim, Gonal-F, or Menopur) to undergo superovulation, Carolina Conceptions recommends that women use vaginal progesterone supplementation for luteal phase support. Progesterone supplementation should begin four days after Ovidrel, that is, two days after timed intercourse or intrauterine insemination.

The progesterone can be administered in multiple forms, which includes 50 mg vaginal suppositories, Crinone vaginal gel, or Endometrin vaginal inserts. All vaginal routes of progesterone are absorbed through the vagina and act directly on the uterus, with no significant effects on circulating blood levels. The progesterone acts directly on the target, which is the inner lining of the womb, or the endometrium. Unfortunately oral progesterone is not effective for this purpose. Often the progesterone is continued for 8 to 10 weeks of gestation. After this time the placenta makes sufficient amounts of progesterone to sustain the pregnancy.

 Why is progesterone prescribed?

The injectable gonadotropins cause the ovaries to produce multiple follicles which elevate estrogen levels. The high estrogen levels can cause the pituitary to significantly reduce the release of LH, which is what in turn is supposed to cause the ovary to make progesterone. Furthermore, the use of GnRH antagonists (Antagon, Cetrotide), which prevent premature ovulation in superovulation cycles, also reduce LH release for an extended period of time. If adequate progesterone is not made, then the lining of the uterus will not develop properly and there would be a greater risk of implantation failure or miscarriage.

Are there any recent studies that support the use of progesterone after insemination?

Yes. Erdem and colleagues published a study in Fertility and Sterility in 2009 that showed that clinical pregnancy rates and live birth rates were twice as high in women who used luteal progesterone support. Live birth rates per cycle were 17.4% in women who used vaginal progesterone as compared to 9.3 % in those who did not use any progesterone. Other studies have shown that pregnancy rates are higher when progesterone supplementation is provided whenever Cetrotide and Antagon are used.

We met with Dr. Park. He was amazing! After running some tests and a few procedures they found that I had low progesterone as well of significant scar tissue in my uterus. They performed a follow up surgery to remove the scar tissue and we did a few months of drug therapy to help my body ovulate. We we’re finally pregnant! They were there through it all. The entire staff was like family. They genuinely cared that our family was getting our rainbow baby. In June of 2016 our son was born healthy and amazing. Thank you for everything!

– J.J., from NC