How Does Your Menstrual Cycle Affect Your Blood Sugar Levels?

Menses, the menstrual cycle, menstrual period—whatever you want to call it, we're sure you agree that it's a time of the month that's never much fun. In fact, they can be downright lousy, regardless of how old or how healthy you are. And the time before that—typically between ovulation and a menstrual period—can be even worse. As many as three in four people who menstruate experience depression, irritability, and cravings in the run-up to their period. This is the infamous PMS or premenstrual syndrome. People with hormonal disorders like polycystic ovarian syndrome (PCOS) can experience even more symptoms.

Why does any of this happen? During that time of the month, your body produces many hormones, which explains why you probably don't feel like yourself just before your period starts. The average menstrual cycle lasts around 28 days, measured from the day your period begins to the day before your next one starts. However, everyone's body is different, which is essential to remember when discussing the menstrual cycle. On average, you begin experiencing a menstrual cycle when you're between 11 and 14-years-old. 

So, what's the deal with menstrual cycles, and are all these hormonal changes risk factors for higher blood sugar and diabetes? Getting your period can be more than enough to deal with. And if you suffer from diabetes or other issues concerning your blood sugar, you may need to track your cycle and its effect on your blood sugar. There are multiple phases in your menstrual cycle, and in each one of them, your body and hormones will be a little different. 

Read on to learn more about the hormonal fluctuations, phases in your menstrual cycle, and whether they have any bearing on diabetes and high blood sugar. 

The Different Phases of Your Menstrual Cycle

1. The Menstruation Phase: This is your actual period. Your period is when you shed the uterine lining. During this phase, your levels of estrogen and progesterone are low.
2. The Follicular Phase: This is the duration between the first day of your period and when you begin ovulation. During this phase, your estrogen level rises, and an egg prepares to be released from your ovary.
3. The Proliferative Phase: After your period is over, your uterine lining will begin to build itself back up again.
4. The Ovulation Phase: Midway through your cycle, you will release an egg from your ovary. Your estrogen levels will peak just before this happens and then drop right after the release.
5. The Luteal Phase: This is the time between ovulation and before the start of the menstruation phase when your body will prepare itself for the possibility of becoming pregnant. During this phase, progesterone is produced, will reach its peak level, and then drop back down.
6. The Secretory Phase: During this phase, your uterine lining begins to produce chemicals that will help support a pregnancy that has developed. Or, it will start to prepare the uterine lining to break down and shed if you do not become pregnant.

Does Your Menstrual Cycle Affect Your Blood Sugar Levels?

If you struggle to maintain your glycemic levels, you may have more trouble the week before you begin the menstruation phase of your cycle. This may be puzzling if you've held regular exercise or eating habits during this week. This isn't something that you are imagining or not managing to control correctly. It is because your body is undergoing hormonal fluctuations and changes during this time. 

The hormone progesterone has been shown to increase insulin resistance during the week before you get your period. So, during your luteal phase (when your progesterone levels spike), you may find that your body isn't responding to the insulin it creates or the insulin that you take nearly as well as it should be. This may result in hyperglycemia and blood sugar spikes when you least expect them. It is important to note that progesterone can also cause pesky carbohydrate cravings. When you indulge in these cravings, it can spike blood sugar.

During your luteal phase, it's essential to check your blood sugar levels more often and make sure you're maintaining your diet well. Not everyone has the same responses, so it can be helpful to use a tool like a continuous glucose monitor (CGM) during a couple of your menstrual cycles. It can help you track your blood glucose levels each month during each phase of your cycle. 

On the other hand, estrogen can encourage insulin sensitivity or increase insulin resistance, depending on your dietary state. Since an estrogen deficiency or impaired estrogen signaling could be linked with insulin resistance, this may be a risk factor for obesity and type 2 diabetes. This means that when you enter your ovulation phase, your estrogen levels rise, and your insulin resistance lowers as your estrogen levels spike. You may not notice as significant an impact on your blood sugar during your ovulation phase as you do during your luteal phase.

Long story short? The answer is yes; the changes during your menstrual cycle can affect your blood sugar levels and impact diabetes management. 

Does Birth Control Affect Your Blood Glucose Levels?

Now that we understand more about how hormonal fluctuations affect your body during your menstrual phase, it may be easier to examine what externally produced hormones do to your body during your cycle. Interestingly, in the 1800s and early 1900s, doctors could only prescribe the birth control pill for things like 'menstrual regulation’ or cycle control—and only to married women. Prescribing it for any reason apart from birth control was alright, but birth control itself was against the law! Doctors still exercise some caution when prescribing hormonal birth control because of the effects the hormones could have on insulin resistance in some. 

There are many different forms of birth control to consider: 

1. The birth control pill may run a higher risk of directly affecting your blood sugar levels and insulin resistance. You have to remember to take the pill every day at the same time. Birth control pills may also have specific side effects like heart attacks, stroke, and heart disease (common among those with diabetes). 
2. Some opt for an injection of depot medroxyprogesterone acetate. This method lasts for three months at a time, so you only have to think about taking birth control four times a year. This form uses progestin, and the side effects may include weight gain, hair growth, and headaches. 
3. Vaginal rings are another form of birth control. The flexible latex rings contain estrogen and progesterone and are usually easy to insert and remove. They can be a good option for people with latex sensitivities and are often more convenient than birth control pills. Some of the side effects are similar to those of the birth control injection. 
4. IUDs or intrauterine devices can be hormonal and non-hormonal. Non-hormonal devices are copper IUDs, colloquially called 'copper Ts' because of their T-shape. The copper IUD offers a solution that doesn't directly affect your hormones. Those with diabetes may see an increased risk of developing infections with this contraceptive device. 

When it comes to birth control, it's a good idea to have an in-depth conversation with your gynecologist. You should discuss whether you can use birth control and what method is best for your body and your needs. This is especially important if you have diabetes. 

Once you begin taking any medication that contains hormones, make sure to monitor the effects that it is having on your body and your blood sugar. A continuous glucose monitor (CGM) can be the perfect tool to help you monitor potential shifts in your blood glucose levels as your body adjusts to it.