Fertility treatments are expensive and stressful, and for many of us, we only have a window of a few cycles to get it right. That makes every single step of the process incredibly important, which only adds to the overall anxiety. Sigh. 

For those who are new to the world of Assisted Reproductive Technology (ART), some IVF and IUI protocols require you to inject yourself with human chorionic gonadotropin (hCG) at a very specific time during your ovulation cycle. Also known as the "trigger shot," this can be a lot of added pressure for someone without a Doctorate in Pharmacy.

hcg trigger shot

Getting the timing of the trigger shot wrong can potentially set you back an entire month of treatment, which is why it's important to understand what the hCG trigger shot is, why it’s needed, and what to do if you make a mistake with yours. Now let's dive in. 

hCG Trigger Shot Mistakes

The hCG injection — also known as a "trigger shot" — helps mature and release eggs from the ovaries and is an important part of the IVF process. It's completely normal to feel a bit nervous about administering the shot; nobody likes needles, especially under pressure! However, if you understand how it works and set an alarm to ensure that you do it at the right time, you’re very unlikely to make a mistake. 

It's crucial to keep in mind that the hCG trigger shot is usually administered about 36 hours before an egg retrieval procedure (this timing may differ slightly with IUI procedures). This allows the egg to mature and release from the ovary, which is necessary for fertilization. If you don't administer the shot at the correct time, it's possible that the egg(s) may not be mature at the time of retrieval. 

person wearing latex gloves handling an hcg trigger shot

What happens if you take the trigger shot too late (or too early)?

If you administer your hCG trigger shot at the wrong time, your fertility specialist may recommend postponing the egg retrieval procedure until your next menstrual cycle. It really depends on how many hours you were too early or too late. That's why it's important to keep your fertility specialist in the loop. Life happens — traffic, sick children, unexpected phone calls. But if you were only out by a couple of hours, try not to panic. Your specialist may be able to move your egg retrieval appointment to later in the day to make up for the lost time.   

If you’re way off with your shot, however, you’ll probably have to go through the entire process again, including taking medications and undergoing fertility testing. As you can imagine, this is best avoided, so try to plan your day around making sure you have enough time to correctly administer your trigger shot. The right timing and triple-checking your dosage can make a massive difference in the outcome of your cycle. 

What if you give yourself the wrong dosage of the hCG trigger shot?

Another potential mistake that patients make with the hCG trigger shot is administering the wrong dose. The dosage of hCG that you'll be given is based on your specific treatment plan and is tailored to your needs. If you accidentally give yourself too much or too little of the medication, it could affect the timing and success of the egg retrieval procedure. 

If you're unsure about the correct dosage of the hCG trigger shot, it's important to reconfirm with your fertility specialist, nurse, or pharmacist. They'll be able to give you the correct information and ensure that you're administering the medication safely and effectively. 

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Trigger shot mistakes: what next?

We know it’s easier said than done, but if you make an error with your trigger shot, try to stay calm. Medication mistakes happen. You may run out of needles, the syringe may crack, or you could get that essential timing wrong. If you panic, you’re likely to only make things worse. The most important first step is to call your fertility clinic and explain the situation. They'll be able to advise you on the next steps and determine if any changes need to be made to your treatment plan.

It's also a good idea to keep a record of all your medication doses and the timing of when you take them. This can help you keep track of when you took the hCG trigger shot and ensure that you're administering it at the appropriate time.

Making a mistake with your hCG trigger shot can be frustrating and stressful, but it's important to remember that your fertility team is there to support you and help you through the process. If you do make a mistake, don't hesitate to reach out to them for guidance. With the right support, you can get back on track and continue with your fertility treatment — maybe even in the same cycle. 


​​Michelle Meyer is a freelance medical writer. She is busy completing an MSc in Physiology and Pharmacology and has been in the health and wellness industry for nearly two decades. Her interests include women’s health, mood disorders, and oncology.