By Kristi Angevine, MD
Q: Is it normal for my periods to go away or be really light when taking birth control pills?
One of the most common side effects to birth control pills (and other hormonal forms of birth control as well) is light or absent periods.
This often freaks people out if they don’t know to expect it, but please know, it’s totally normal.
To make sense of it, let’s look at the reason why this happens.
When you’re not on birth control pills and are having regular periods, then your body has a rise and fall of a few different hormones that prep your body to release an egg from your ovary, near the middle of your cycle.
This rise and fall pattern of hormones makes tissue in the uterus build up in preparation for a pregnancy. I like to think of it like this: layers of tissue build up, so in case you get pregnant, an embryo can burrow into them and have all the nutrients it needs. These layers of extra tissue build gradually through your cycle. If, at the end of your cycle, you haven’t gotten pregnant, this tissue sloughs off and comes out as the blood you see during your period.
When on birth control pills, you’re taking in the same amount of hormone every day in the form of the pill. This dose tells your brain NOT to make that typical, rhythmic, rise and fall of hormones that signal an egg to be released.
So, when there is the daily intake of pills, there is no egg released, and little or no tissue layers form inside the uterus in preparation for a pregnancy. If you could take a camera and look inside the uterus of someone on birth control pills, it often looks vacant, like a moonscape. So at the end of the active pills, often, there may be nothing inside to slough off and come out as your period.
If this is you, count your lucky stars— less periods = less pain, less pads, less tampons, less fuss.
But, are there times when you SHOULD be concerned about not having a period? Absolutely! If you are concerned that you could be pregnant, you should take a pregnancy test. Also, if you are not having regular periods and you are NOT on hormonal birth control, your doctor needs to evaluate you to see why that is. In fact, you may need very important testing and or/treatment.
Kristi Angevine, MD is a board certified Ob/Gyn who loves to ensure women really understand their health. She practices in southeast Tennessee and enjoys helping her patients have the smoothest pregnancies possible. Her interests include general obstetrics, contraception, minimally invasive surgery and preventive care. In her free time, she enjoys mountain biking and outdoor adventures with her husband and daughter.