In a culture where implicit messages concerning the menstrual cycle are rooted in shame and stigma, it’s hard to imagine anyone advocating that people have sex during that time of the month — and yet, here we are.

Up until recently, women have lacked the technology to meticulously track their monthly cycles. Sure, there were paper calendars and empty birth control packs to indicate when they could anticipate their next flow, but with today’s apps and trackers, women are tuned into much more than the days they should have tampons handy. Now they can monitor their mood and behavior in the weeks leading up to and during their period, as well as when exactly they’re ovulating and, if they’re expecting, contractions and labor symptoms. So what we’re saying is that, before these precise tracking methods existed, it’s likely women and men had accidental period sex many, many times.

What’s changed, though, is the number of men and women who have come out and said, “Hey, you should be doing this on purpose.” In 2012, Vice published a story titled “Why Period Sex Is the Best Sex (and Should Probably Be Mandatory)” by writer Kat George, who a year earlier made a similar case on Thought Catalog. George said she wanted nothing to do with a man who wouldn’t have sex during her period, because why wouldn’t he? She said she’s increasingly aroused during this time, is “pre-lubricated and ready to do some really awful things that non-hormonal pre-blood me probably wouldn’t do unless she had a glass of wine or two.”

The comments George got ranged from “badass article” to “You are a dirty pig.” Then, in 2014, George was no longer in the minority: Maureen O’Connor wrote about men who not only enjoyed period sex, but preferred it for The Cut; these types are known as “bloodhounds.” And in case men were still confused about what exactly goes on during this time of the month, Vice was back in 2015 with “A Guide to Periods for Men.” The line where the writer Lisa Ludwig recalls men describing a period as smelling “like raw steak” has particular staying power.

Since then, there’s been widespread debate on whether or not to have period sex. What should men and women know about it? Are there any risks? Medical Daily touches on some of the pros and cons here, though ultimately this is a conversation desiring women and men should have with their partners. Some women are liberated by period sex and some men request it, but these are not universal feelings.

Pros

A quick recap of biology class: The menstrual cycle normally lasts 28 to 32 days, starting on the first day of a woman’s period, when hormone levels are high. After about a week, the bleeding stops, and a week or so later a mature egg is released to begin ovulation. If the egg isn’t fertilized, hormone levels begin to drop as the end of the month nears, signaling to a woman’s body that it’s time for her next period.

So George is not wrong when she says her arousal and lubrication peak during her period — rising estrogen and testosterone levels can make women feel more sexual. A survey from the University of Virginia in Charlottesville, however, found women were significantly more interested in sex and were more sexually satisfied when they got busy mid-cycle, which is around the time of ovulation, Psychology Today reported. "The chemistry of your body is preparing for reproduction … that predisposition translates to how you behave when you're feeling more sexual,” Dr. Hal Danzier, reproductive endocrinologist and cofounder of Southern California Reproductive Center, told Woman’s Day.

And while the blood can discolor bodies, sheets, and furniture, it can also double as lubricant. There’s a myth that women bleed more when having sex on their period, but according to Dr. Debby Herbenick, this is not true. The broken down blood and uterine tissue that women release is the result of previous weeks’ build up, she said, so if period sex has an affect on this at all, it hastens how quickly women expel these fluids, thanks to the way the uterus contracts during orgasm. To that extent, period sex may even shorten the length of a woman’s period. Bonus: some women find these contractions reduce menstrual cramps.

At the end of the day, humans are animals and period sex can speak to a very basic, primal urge. This “uncontrollability means the potential for sexual glory is high,” O’Connor wrote; one anonymous man speaking to YourTango said the animalistic undertone of period sex was largely why he welcomed it.

Cons

There’s always a catch, right? Early to mid-cycle may be prime time to give into these very human urges, but just as it can elevate a sexual encounter, it can also raise the stakes for humiliation. Aside from everything being tinged red, one woman O’Connor spoke to said period sex made her feel “gross and guilty.” She found, too, that even the loudest advocates still recoiled from coagulated blood. The same could probably be said for smell, which could be more concentrated given Herbenick’s earlier statement that women don’t bleed more but can bleed more at once.

The repulsion echoes the stigma that activists are currently working to end. It wasn’t so long ago that menstruating girls were forced to spend a week in a dark room. The Huffington Post reported that the practice, also know as the chaupadi tradition, was outlawed in 2005, but still exists in rural villages in western Nepal. In Malawi, HuffPost reported, shame is so pervasive that parents don’t even talk to their kids about it.

On a lesser scale, if women don’t feel good about themselves, as is known to be the case when they get their period and the cramps, sensitivity, and breakouts that come with it, it can impede their sex lives. One study found that “personal and interpersonal expectations and beliefs affect one’s sexuality and sexual function,” with perfectionists in particular reporting decreased arousal and increase sexual anxiety in circumstances where they feel like they have to be, well, perfect.

Let’s say these social and cultural ideas and stigmas are not a factor for you and your partner — one con that may apply is the risk for unplanned pregnancy and sexually transmitted diseases. In a story for Parents, Jennifer Barton posed the pregnancy question to Dr. Michele Hakakha, a Los Angeles obstetrician and gynecologist and co-author of Expecting 411: Clear Answers and Smart Advice for Your Pregnancy. Hakakha said that since not every woman follows the normal menstrual cycle, and sperm can live for three to five days, it’s possible for women having period sex to get pregnant. Since the cervix is also more open than usual during this time, O’Connor reported it could increase women’s exposure to harmful bacteria and STDs. In other words, period sex isn’t license to pass on the condoms.