Have you ever felt personally victimized by your TikTok feed? Let me be more specific: have you ever scrolled through your For You Page and come across a video that so accurately described something you’ve gone through that you felt attacked? Because that’s how a lot of us at POPSUGAR felt when we stumbled across people describing the horrors of the luteal phase.

“I woke up this morning and looked in the mirror and saw an 85-year-old woman that grew up in trenches,” shared TikTok user sam_d0ll, a person who objectively does not look like an octogenarian. She posited that the luteal phase of our menstrual cycle — the back half before your period starts — makes us go, in her words, insane. “All of a sudden, we’re irritable and bloated and our faces look different shapes and we’re mean as hell,” she said.

This isn’t just something one rando on TikTok experiences. Based on the comments section alone, many other people with uteruses are also going through it during this part of their cycle and have no idea why. “I lose my mind until my period starts,” one person wrote. “We only get 6 good days a month,” added another.

But what is it about the luteal phase that makes us look and feel like absolute garbage? We dug into the science with an expert to figure out what exactly is going on.

Hold On . . . What Is the Luteal Phase?

In case high school health class didn’t cover this (because mine certainly didn’t): the luteal phase is the name of the second half of your menstrual cycle, says Michael Krychman, MDCM, board-certified ob-gyn and Chief Medical Officer of healthcare company HerMD. In the average 28-day cycle, he says the luteal phase happens around day 14 and goes to day 28.

Immediately prior to the luteal phase is ovulation, when your ovaries expel a mature egg in order to be fertilized. That timing is important because, in the first part of the luteal phase, your body is acting as if that egg was fertilized by sperm — and thus is getting you ready for pregnancy. “You’ll see a rise in the hormone called progesterone, which basically is the hormone that prepares the uterine lining for pregnancy,” says Dr. Krychman. Progesterone makes that lining get nice and thick, so that an embryo has a spot to latch onto and then grow.

If the released egg doesn’t meet a sperm and you do not get pregnant, your ovary (specifically the corpus luteum, the spot where your egg came from) shrinks up and stops making progesterone. Your progesterone and estrogen (another key sex hormone that helps regulate your menstrual cycle) levels plummet. Without progesterone to support itself, your uterine lining thins and sheds, resulting in your period, says Dr. Krychman.

Just FYI: if you’re on hormonal birth control such as the Pill, you likely aren’t experiencing such variation with your hormone levels during the luteal phase. “Oral contraceptives are basically taking over the control of the hormonal cycle,” Dr. Krychman says. Whether your Pill of choice has both estrogen and progesterone, or just progesterone, your hormonal shifts are being evened out, he says. That’s not a bad thing; that’s how the Pill prevents pregnancy.

How Could the Luteal Phase Impact Me Physically and Mentally?

The drastic changes in your hormone levels during the luteal phase — going from high highs to very low lows — can have different effects on people, says Dr. Krychman. “There’s a whole variety of symptoms that you can get like anxiety and headaches and mood swings,” he says. “Some people get breast tenderness, weight gain, acne, trouble sleeping, changes in sexual desire, bloating, [and] cravings.”

These varying symptoms, triggered by hormonal shifts, might explain why some people feel like a hot sack of trash during their luteal phase. Other people, Dr. Krychman says, may not notice a lot of difference — or might even feel better than usual. (Do we hate them? No. But, maybe.)

There’s not a ton of research as to why the luteal phase is associated with a wide variety of symptoms and experiences. But we can take a few educated guesses on at least some of these issues. Take acne, for example. Estrogen helps inhibit testosterone and other hormones that trigger oil production in the skin; when your estrogen levels are low (as they are at the end of the luteal phase), your body produces more oil, which can cause breakouts. Progesterone and estrogen make your breasts swell, which can cause tenderness when those hormones are at their peak earlier in the luteal phase. Estrogen can also make you retain water, which can cause bloating and make your face look puffy. (Fun!)

Some people also have significant mood changes during the luteal phase thanks to premenstrual dysphoric disorder (PMDD). People with PMDD have serious, sometimes debilitating mental health symptoms like anxiety, depression, or irritability in the week or two leading up to their periods — changes that are completely gone at other times in their cycle. The leading theory is that people with PMDD are especially sensitive to the hormonal shifts of this phase of the menstrual cycle, which impacts their brain chemistry and thus their mood.

However, Dr. Krychman notes that mood and physical health are complex; how you’re feeling on a given day can’t be chalked up simply to the activities of one hormone. (Because TBH that’s pretty reductive!)

“There are other things that influence hormones,” Dr. Krychman says, and thus how you’re feeling physically and mentally. If you’re really stressed out because of work, for example, your cortisol levels (aka your “stress” hormone”) might be sky high, he says. And chronic stress can make it hard to sleep, which can contribute to a bad mood, dull skin, and other issues.

It’s also important to mention that there is a lot of individual variation in how people experience their luteal phase and other parts of their menstrual cycle. “There are some women who are ultra sensitive to [hormonal] fluctuations,” Dr. Krychman says. These folks often know when they’re ovulating or when their period is about to start because they can feel different symptoms at different times. Other people, he says, “sail through the fluctuations.”

It’s unclear why some people are so vulnerable to these changes while others don’t feel a thing. “I think it is down to individual physiology and genetic predisposition,” Dr. Krychman says.

Is There Anything I Can Do About the Luteal Phase Making Me Feel Like Death?

Just because not everyone is affected by what’s going on during the luteal phase doesn’t mean that what’s happening to you isn’t important or worth addressing. “Women need to be empowered, and they don’t need to suffer in silence,” Dr. Krychman says.

Dr. Krychman says the first thing to do if you’re noticing frustrating or debilitating symptoms happening at a consistent time each month is to talk to your healthcare provider to troubleshoot what’s going on. (It might be helpful to keep track of your cycle and symptoms in a journal or a secure period-tracking app like Drip or Euki, so that you’re armed with data points.) He says your doctor may recommend hormonal birth control, like the Pill, to help even out the hormonal fluctuations and thus help manage some of the symptoms you experience. If you have PMDD, you might be referred to a psychiatrist for more support and potentially mental health medication.

Dr. Krychman says that there are other things you can do to help support some of the symptoms you experience, along with your overall well-being. “There’s calming hobbies that lower cortisol: meditation, yoga, mindfulness,” he says as an example. He also recommends regular exercise to manage stress, support your mood, and cardiovascular health. These aren’t a balm for serious conditions like PMDD, of course, but rather things you can do regularly to help support your health all the time.

The bottom line: the luteal phase can be a rough ride for some of us, but just because you’re “hormonal” doesn’t mean you should accept unpleasant symptoms at face value. Seek help and support, and give yourself a break the next time you wake up and feel like the Crypt Keeper.