Apparently, people are putting period blood on their faces now.

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Another day, another quest for the ultimate bio-hack, elixir of youth, and magical bullet to reverse the ageing process.

But if you felt squeamish at the thought of putting salmon sperm on your face, brace yourself for the latest beauty trend: "menstrual masking."

Yes, people are now applying menstrual blood directly to their faces, and it's all over TikTok and Instagram as the latest DIY anti-ageing remedy.

In photos and videos circulating online, women proudly display their blood-smeared faces, claiming miraculous skin benefits. At the time of writing this, I did consider including some imagery, but I will leave it to you if you'd like to look up #periodbloodfacemask.

Watch: Would you try menstrual masking for real? Post continues below.

On the one hand, it's great we're not stigmatising period blood anymore. We've come a long way since menstruation was taboo and women were encouraged to sit out certain activities during their cycle.

But slathering it on your face as a beauty treatment? That's quite something.

So, should you be reaching for your period cup instead of moisturiser? We asked an expert to unpack the menstrual masking trend, including whether period blood is good for your skin, and if it's safe.

First up… what's actually in menstrual blood?

Period blood is more complex than most people realise.

"When you say menstrual blood, you think it's just blood, but actually, just over a third of that is actual blood," Dipa Kamdar, Senior Lecturer in Pharmacy Practice at Kingston University, told Mamamia's twice-daily news podcast The Quicky.

"The rest of it's made up of bits of your uterine lining, your endometrial tissue, the dead cells, some vaginal secretions and cervical mucus, hormones, and proteins. There are lots of things mixed into what menstrual blood is made up of."

"It can also contain bacteria, which are picked up when it goes through the vaginal canal and passes out. So it is unusual to think about applying this to the face."

Is period blood good for skin?

Women applying menstrual masks claim they see real results, stating it seems to rejuvenate or 'heal' their skin. But is there any science to this?

"What they found in some of the studies is that it does actually contain what we call stem cells, that are derived from menstrual blood," Kamar explained.

"Stem cells are basically what we call unspecialised cells in the body, and they can develop into different types of what we call specialised cells. They could develop into muscle cells or blood cells, or brain cells. So potentially, they could repair tissue or make your skin feel renewed."

In short, the science makes sense in theory, but there's a catch.

"Stem cells could reduce the appearance of wrinkles. They might help any sun damage that might have been caused by spending too much time in the sun, premature ageing, and ageing."

"I guess the problem is, there haven't really been too many studies done on this practice that actually say outright that this is actually going to work."

Menstrual masking vs 'vampire facials' and PRP.

Kamar confirmed menstrual masking isn't the same as those celebrity vampire facials you might have heard about. The key difference is in the process and safety standards.

"With vampire facials, they use something called platelet-rich plasma (PRP). It's in a very controlled setting; it's all done under sterile conditions by a professional. So it is very different compared to menstrual masking, which is a DIY therapy."

"What happens [with vampire facials] is the patient's blood is extracted, and then it's in a lab. It's spun around. They separate out the platelet-rich bit that they need for the procedure, and then that's injected into the skin using fine needles."

Is period blood safe for skin?

Applying menstrual blood to your face comes with some serious health concerns.

"The biggest risk is if somebody has a cut on the face or broken skin. Certain bacteria live in our bodies and don't cause any harm. But if you're transferring some of that bacteria, and that comes out into the menstrual blood, and then is applied to the skin on the face, that could lead to a deep tissue skin infection, like cellulitis," Kamar said.

"The other risk is that there is a chance of passing on something like sexually transmitted infections as well to the skin."

Your individual health status plays a major role in how risky this practice could be, too.

"If you're somebody that has other medical conditions, an immunocompromised system or diabetes, where your immune system's not 100 per cent, then you're going to be at higher risk of picking up infections."

To summarise: Like a lot of TikTok beauty trends, menstrual masking has theoretical benefits backed by limited research, and very real risks backed by microbiology.

Until there's actual clinical evidence and proper safety protocols, you might want to consider keeping your period blood contained to your sanitary products, and your skincare routine firmly in the realm of the dermatologist-approved.

You can hear the full episode of The Quicky with expert Dipa Kamdar below.

Feature Image: Getty.