hCG Shots During Fertility Treatments

Human chorionic conadotropin (hCG) is a hormone secreted early in pregnancy by specialized cells called trophoblasts and later by the placenta. It helps to maintain high levels of progesterone, which is critical for the success of the pregnancy. hCG is also the hormone detected by urine and blood pregnancy tests.

Syringe and medicine vial sitting on a medical report
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Fertility Treatments With hCG

Because hCG is similar in structure to luteinizing hormone (LH), when there is a mature egg follicle in the ovary an injection of hCG can cause the egg to mature and be released. The medication can be used alone, in an ovulation induction cycle as with intrauterine insemination or during in vitro fertilization.

The hCG injection will cause ovulation approximately 36 hours after you take it, allowing your healthcare provider to better time intrauterine insemination or the egg retrieval.

Many brands and forms of hCG are available. Your healthcare provider will prescribe the one most appropriate for you. Injections can be given either subcutaneously or intramuscularly, depending on the brand.

Pregnancy Tests and hCG

Remember that hCG is the hormone detected in urine pregnancy tests. When you take hCG as a medication, it may persist in your body (and urine) for up to two weeks. If you take a pregnancy test during that time, it will turn positive as a result of the medication, not a pregnancy.

Wait at least two full weeks from the date of administration to ensure that a positive pregnancy test is due to pregnancy and not residual medication in your system.

Preparing or Mixing hCG

One form of hCG, Ovidrel, comes in a 250 microgram (mcg) prefilled syringe. Once you open the box, the medicine is already prepared and loaded in the syringe with the needle attached.

Simply open the packaging, remove the air bubble by holding the syringe with the needle facing up, and slightly depress the plunger until all the air is removed, and inject the medication subcutaneously.

Pregnyl or Novarel (hCG, human chorionic gonadotropin) also comes in a box with a 5,000 10,000 or 20,000 unit vial of powder and a vial of diluent (liquid) which is used to mix the powder. Your healthcare provider will tell you how many units of the medicine to take and how they prefer you to mix it.

For example, if you are taking 10,000 units, you will remove 2 milliliters (mL) of diluent and inject it into the powder. Allow the powder to dissolve and then pull the entire 2 mL back into the syringe. Inject the medication intramuscularly or subcutaneously, according to your healthcare provider’s instructions.

When to Take hCG

This medication is taken once there is a mature egg follicle in the ovary. Your healthcare provider will most likely give you a specific time or time frame to take the medication. It is important to tell your healthcare provider if you do not take the medication on time in case any adjustments need to be made.

If you will be having intercourse or intrauterine insemination, ovulation will occur approximately 36 hours later, so the day of the injection and two days following it are your critical days. If you will be having egg retrieval as in an IVF cycle, it will occur close to that 36-hour mark so as to optimize the maturation but avoid ovulation.

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3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wang W, Zhang X, Wang W, et al. The time interval between hCG priming and oocyte retrieval in ART program: a meta-analysis. J Assist Reprod Genet. 2011;28(10):901-910. doi:10.1007/s10815-011-9613-x

  2. CVS Pharmacy. Ovidrel: solution for injection (250 mcg).

  3. Drugs.com. Human chorionic gonadotropin (HCG) (injectable).

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