What Medications Are Used for Ovarian Stimulation?

By BSc, MSc (embryologist), BSc, PhD (gynecologist) and BA, MA (fertility counselor).
Last Update: 11/02/2016

Egg donors have to administer hormone medications to induce the production of multiple eggs in a single cycle, thereby increasing the success rates for recipients. This process is called controlled ovarian stimulation (COS).

It is the first step involved in the treatment for egg donors after the medical and psychological screening candidates are required to undergo to check whether they meet all the legal requirements to become oocyte donors.

What drugs are used to induce ovulation?

Medications for donating eggs contain hormones for monitoring the development of follicles in the ovaries. They are used to trigger follicle growth, so that the resulting follicles are functional. This is why they are used for "ovarian stimulation".

Month after month, various oocytes start growing, but only one of them develops fully. The remaining eggs degenerate, since they have failed reaching their final stage of maturation.

With hormone therapy, the ovary is stimulated in order for all these eggs to make it to the final stage in the maturation process and do not get lost on their way. Broadly speaking, around 10 to 20 develop fully with donor oocytes.

Gonadotropins and GnRh analogs—either agonists or antagonists—are used to help induce ovulation. The protocol to be followed is determined by the specialist according to the particularities of each donor and her menstrual cycle.

Gonadotropins are the hormones responsible for regulating the menstrual cycle. The following are the ones used to induce ovulation: FSH (follicle-stimulating hormone), LH (luteinizing hormone), and hCG (human chorionic gonadotropin).

  • FSH: It triggers the maturation of the ovarian follicle where an egg is developing.
  • LH: It leads to ovulation and can be used as a supplement to reproduce the conditions of the natural menstrual cycle.
  • hCG: Shots are administered 32-36 hours before ovum pick-up. It induces ovulation within 36 hours after being administered, which means the eggs should be collected from the ovary before being released naturally to the Fallopian tube, that is to say, prior to ovulation.

Both GnRh agonists and antagonists are used to diminish brain control over follicle growth, which allows determining the day of ovulation more properly.

  • GnRh agonists: They allow for all the developing eggs to continue with the process simultaneously, so that no oocyte ends up being more mature than the others.
  • GnRh antagonists: They are used more often due to the greater number of advantages they present over GnRh agonists, as they are usually well-tolerated by women, with only mild stimulation.

Although rarely, ovarian stimulation carries some risks. To learn more about them, we recommend you to visit the following article: Potential risks of egg donation.

How to administer fertility medications

The administration of ovulation-stimulating drugs is done via subcutaneous injections. They are self-administered following the protocol established by the doctor. Consistency is crucial in this sense: should the donor unfollow this calendar by injecting lower doses or administering the medications wrongly, their outcome could end up being counterproductive.

Sometimes, common medication administration errors, whether related to the dose or the moment of injection, leave specialists no alternative but to cancel the cycle.

Normally, the beginning of the treatment is scheduled for the day of menstruation, that is, the first day of the menstrual cycle. The treatment cycle takes around 10 days, depending on the donor's response to medications.

Regular check-ups are carried out while the donor is on ovulation induction with the purpose of monitoring follicle growth as well as determining the optimum moment for ovum pick-up—the surgical procedure for egg retrieval.

Should you need more information, please visit the following post: Follicular puncture for egg collection.

FAQs from users

Can there be any complications with the use of the Puregon Pen?

By José Antonio Duque Gallo BSc, PhD (gynecologist).

The use of the Puregon Pen carries no greater risk than any other gonadotropin.

Can I use pills for ovulation induction instead of subcutaneous injections?

By Andrea Rodrigo BSc, MSc (embryologist).

No, medications for ovarian stimulation are administered subcutaneously with injections, generally into the abdomen area. There exists a nasal spray, but is rather uncommon. Although they are administered with a needle, it is a simple and painless procedure.

What are the main side effects of ovulation induction medications?

By Andrea Rodrigo BSc, MSc (embryologist).

Ovarian stimulation is done with hormone medications, which can cause some side effects. They are not painful or specially severe, though. By no means they are symptoms that could hinder the donor from continuing with her everyday routine.

Commonly, headache, bloating, tiredness, etc. are the most common symptoms during the days leading up to egg retrieval.

In case the donor develops OHSS (Ovarian Hyperstimulation Syndrome), the symptoms derived from it can be moderate to severe. The good news is that only a small percentage of women develop OHSS, and it can be often prevented through ultrasound monitoring. You can get more information about it here: Ovarian Hyperstimulation Syndrome.

Do fertility drugs lead to gain or lose weight?

By Andrea Rodrigo BSc, MSc (embryologist).

Ovulation induction protocols last around 10 days, so appreciating a weight gain or loss after that is rather unlikely. However, donors can develop a mild water retention as a side effect of hormone therapy, but it occurs rarely.

Can fertility drugs cause early menopause?

By Andrea Rodrigo BSc, MSc (embryologist).

No, ovarian stimulation does not affect the donor's fertility, as eggs that would have degenerated end up developing fully, so it does not reduce the number of eggs which would have grown naturally, which is to say, the chances of getting pregnant naturally in the future do not diminish.

What are the main reasons for poor response to fertility drugs?

By Andrea Rodrigo BSc, MSc (embryologist).

Women requiring larger doses of stimulation drugs are commonly called "poor responders". Although there is no clear definition for what can be considered a low response to IVF drugs, many authors use a cut-off of less than 4 mature eggs at the time of hCG shots or an estradiol level of less than 500.

Low response is detected through ovarian reserve testing, including basal FSH levels. Ultrasound assessment of the ovaries and the antral follicle number are also good predictors of poor responders to stimulation drugs.

A cycle can be cancelled if less than 4 mature eggs are produced or if no response is obtained at all.

Are fertility drugs harmful or dangerous?

By Andrea Rodrigo BSc, MSc (embryologist).

The associations between IVF drugs and the risk of ovarian or breast cancer are weak, and conclusive studies are scarce to date. There is no convincing evidence that they raise a woman's risk of developing any of these types of cancer.

Can you travel by plane with fertility meds?

By Andrea Rodrigo BSc, MSc (embryologist).

Experts recommend not to travel abroad by plane while on fertility treatment. Instead, you are encouraged to look for ways to relax and postpone your journey if possible.

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


Authors and contributors

 Andrea Rodrigo
Andrea Rodrigo
BSc, MSc
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia. Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia along with the Valencian Infertility Institute (IVI). Postgraduate course in Medical Genetics. More information about Andrea Rodrigo
 José Antonio Duque Gallo
José Antonio Duque Gallo
BSc, PhD
Bachelor's Degree in Medicine and Surgery from the University of Valencia. Specialist in Obstetrics & Gynecology. He has an extensive experience in the field of Human Reproduction. he has been Head of Human Reproduction Service at the Miguel Servet University Hospital of Zaragoza ans is currently the Medical Director of the GOBEST Clinic in Zaragoza. More information about José Antonio Duque Gallo
Licence: 505005367
Adapted into english by:
 Sandra Fernández
Sandra Fernández
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

Find the latest news on assisted reproduction in our channels.