Reviewed by

Morgane Leten - Nutrition & Fertility Coach

  • Hormones

How Your Breasts Change During Your Cycle

Hormones can cause a lot of changes in your body over the course of a month. Whether it’s sleep disruption, energy changes or skin challenges, hormones run the show when it comes to how you feel at any given point in your cycle. But did you know that your breasts can change week-to-week according to your cycle? They can actually get bigger over the course of your menstrual cycle due to hormonal fluctuations! Breast changes during your menstrual cycle can also include some pain and lumpiness too. 

So don’t worry. You’re not going mad. Here’s everything you need to know about how your breasts change during your cycle, especially during and after your period. 

Hormones and your breasts

Given that hormones were what caused our breasts to grow in the first place, it should come as no surprise how much hormones affect our breasts each month. During your cycle, the hormones progesterone and estrogen rise and fall, and that’s what causes changes to your breasts. Estrogen stimulates the growth of milk ducts, and progesterone stimulates the formation of milk glands. This process prepares your body for a possible pregnancy and, as a result, your breasts will enlarge slightly. If you don’t become pregnant, your breasts will return to their usual size. 

By the way, we’re not talking about an increase from an A cup to a DD. It’s a little more subtle than that! You will likely be the only one to notice the changes.

How your breasts may change

Your breasts will change throughout the different phases of your cycle. Here’s what to expect during and after your period. 

During Your Period

Do breasts hurt during ovulation? If you experience soreness, how long do breasts stay sore after ovulation? Here’s how it works. 

When your period starts, your levels of estrogen and progesterone are low. But as you get closer to your period, estrogen levels will rise, peaking around mid-cycle. After ovulation estrogen will decrease and progesterone levels will start to rise and play an active role in the second half of your cycle, also known as the luteal phase. All these hormone increases signal your body to start growing your milk glands. It’s the growth of these glands that can make your breasts change. 

When your period starts, your breasts may feel different. They might feel lumpy or uneven.  

During your period, you may even notice that your breasts feel swollen, painful or tender. Don’t panic. They won’t stay like this for long. As soon as your body realizes it’s not pregnant, any symptoms you felt will disappear. We can imagine it's not comfortable to live with painful breasts. If it really hurts and has an impact on your daily functioning this can be because of hormonal imbalances. Talk to one of our experts to see what you can do to relieve the tension. 

Speaking of disappearing, toward the end of your period, your breasts may actually shrink a bit! Because estrogen and progesterone are at their lowest, your breast volume will also be at its lowest during this point of your cycle. 

 After Your Period

During the second half of your cycle, after ovulation, most women notice that their breasts are at their largest. With progesterone levels peaking, you might notice fuller breasts after your period ends. 

 Can I do anything to curb breast changes?

Yes! There are a few things you can do to make breast changes a little less dramatic, especially if you experience quite an intense breast pain during your menstrual cycle.  

  • Avoid high-fat foods
  • Reduce or avoid caffeine in things like coffee, tea, carbonated drinks or chocolate. Opt for herbal teas instead 
  • Try to avoid salt 1-2 weeks before your period starts
  • Get fitted for a good bra, and make sure you have one that offers good breast support (it is shocking how many women wear ill-fitting bras. If you’ve never been measured, find a shop and ask for help. A good bra can be life-changing! We recommend Curve Catch to help you find the right bra) 
  • Try to get your heart rate up with some regular cardio exercise
  • Lara Briden, author of Period Repair Manual recommends adding a supplement with iodine to your diet because studies have shown that  iodine can help relieve breast pain, ovulation pain, and PMS 

 Are there other potential causes of breast changes?

Yes, there are other reasons your breasts could be changing. Aside from your cycle, there are other times when your hormones fluctuate, and any time there is a change in hormones, things can change. Here are a few times you might also notice changes to your chest… 

 Pregnancy

Pregnancy stirs up a new cocktail of hormones which can cause all sorts of changes to your body, notably your breasts! When you’re pregnant, the glands in your breasts that will produce milk will get larger, and this can make your breasts feel lumpy and strange. Some women report loving their “new” breasts when pregnant. It’s like a breast enlargement… only temporary!  

If you’ve already had your baby and you’re breastfeeding, get ready for a whole new experience with your breasts! Not only are they now the primary food source for your baby, but they will also look and feel different too. Pay close attention to your breasts, especially if there is redness, tenderness or pain. It could be a sign of a common infection called Mastitis. This can be treated with antibiotics, so see your doctor ASAP if you’re concerned. 

 The (peri)menopause

Later in your life, as you approach (peri)menopause, hormones will start to change again. You may notice that your breasts will still feel lumpy or tender at certain points in your cycle but as your menstrual cycle stops, these symptoms will disappear.

To learn more about menopause and perimenopause, read our post called Let’s Talk About Perimenopause

 When to call your doctor

When your body changes randomly, it can be a huge source of anxiety. We get that. But remember that breast changes throughout your cycle are common. While every woman is different, it’s normal to have one or all of the following symptoms: 

  • Swelling
  • Tenderness/soreness 
  • Aches and pains
  • Changes in texture 

Most changes shouldn’t send you into a panic but do pay attention to what is normal for you. Examine your breasts regularly in a mirror. If you notice any of the following things, it might be time to see your doctor: 

  • Unusual or new lumps in your breasts or under your arms 
  • Discharge from your nipple (other than breastmilk!), especially if it’s brown or has blood in it
  • Intense pain that impacts your sleep
  • Changes in the size or shape of your breasts that don’t go away when your period ends
  • If your nipple suddenly becomes more pointy or turns inward
  • Changes to the skin on your breasts, including itchiness, redness, scaling or dimples

Do you have questions about your breasts? Talk to our support team. We can help.