Kylie Jenner got a lot of flak in 2016 for crediting her cleavage to her menstrual cycle. But here's the thing: While we obviously can't confirm or deny her party line, she's not being scientifically inaccurate. "Period boobs" are very, very much a thing, and it's super normal for breasts to fluctuate in size depending on the time of the month.
"Changes in the breast are very typical during the menstrual cycle due to hormonal fluctuations," says Jessica A. Shepherd, MD, a Chicago-based ob-gyn and expert for SweetSpot Labs, a feminine hygiene brand. "You may experience [increased swelling], tenderness, or pain. These changes usually subside in some form and are gone by the end of the cycle."
This all being said, Shepherd notes that it's still important to monitor your breasts on a regular basis—both on and off your period—to ensure that nothing is out of the ordinary.
For starters, going up an entire bra size is A-OK—even when you're just in the PMS stage (What a party, right?): "Yes, it is normal to experience some growth in breast tissue during or before periods," says Shepherd. "Estrogen release is high in the first half of the menstrual cycle, and this stimulates growth of milk ducts in the breasts. With this increase in ductal tissue, it can lead to swelling, pain, and tenderness." Not to mention, this might happen more so in one breast than the other, unfortunately leading to temporary asymmetry.
Another thing: While we're told to raise alarm bells when we find lumps in our breasts, it's not always out of the ordinary, especially during our period. "There may be some more lumps during this time because of extra fluid in your breasts," Shepherd explains. "That is why breast exams should not be done during periods."
"Knowing the general consistency of your breast tissue is important, and that's why monthly breast exams at home are helpful," advises Shepherd. Breast tissue is typically pretty lumpy and granular to begin with, but only you (and your doc) can know what's normal for you, which is why if you don't know already, it might be wise to ask your ob-gyn to walk you through a breast exam at your next checkup.
That being said, if (after your period) you feel a firm, hard lump on or near your breast or under your arm, it's probably a good idea to get it checked out, even though it could very well be benign, says Shepherd. She also says to look out for any weird-colored or bloody discharge, or significant changes in the size or shape of your breast.
How to Deal With Period Boobs
A comfortable, stretchy bra is probably a good start, as is the usual TLC you should be treating yourself to during the worst of your menstrual cycle. "Counteract excessive swelling in the breast tissues by eating plenty of vegetables and fruits to decrease water retention," advises Shepherd. "Increasing fiber intake also helps with decreasing overall water retention in the body." She also suggests steering clear of very salty and/or processed foods, which is also good advice in general.
Beyond that, studies show that healthy fats—that is, the omega-3 fatty acids found in flax, fish, walnuts, and avocado—can significantly reduce PMS and period symptoms, including breast tenderness and swelling. Confirmed: Increasing our guacamole intake may be the only silver lining of having a period.
Check out more foods to eat (and avoid) on your period.
Sohrabi N, Kashanian M, Ghafoori SS, Malakouti SK. Evaluation of the effect of omega-3 fatty acids in the treatment of premenstrual syndrome: "a pilot trial". Complement Ther Med. 2013;21(3):141-146. doi:10.1016/j.ctim.2012.12.008