Beyond the Hype: Debunking TikTok’s Biggest Skincare Trends

If you’ve spent even a little time on TikTok, you’ve probably noticed how quickly skincare “glow-up” trends take over. One week it’s beef tallow routines, the next it’s slugging, ice facials, or cryotherapy treatments promising tighter, clearer, more youthful skin. But what does the science actually support?

Let’s start with beef tallow, which has been trending as a “natural” and cheaper moisturizer. Russell et al. (2024) conducted a scoping review looking at how compatible tallow is with human skin. Tallow is basically a solid fat from animals, mainly cows, containing triglycerides and fatty acids that also happened to be found in the skin’s outer barrier. Because of the similarity, researchers suggest it could work as a moisturizing ingredient. The findings concluded that while studies do show that tallow-based products can improve hydration and reduce water loss from the skin. It is not the best product; a product with linoleic acid and pumpkin seed oil actually performed better in supporting the skin barrier (Russell et al., 2024). So, while yes, tallow could be used as a moisturizer, it may not be the most effective method for moisturization.

Where things get more complicated is when we look at the limitations. The research on tallow is still pretty limited, especially when it comes to real human clinical trials. A lot of the evidence comes from lab-based work or animal studies rather than long-term studies on actual skin outcomes in people. There’s also conflicting evidence around irritation—some studies report no issues at all, while others note skin or even eye irritation (Russell et al., 2024). TikTok might frame beef tallow as a skincare miracle, but the reality is that we just don’t have enough strong human evidence to support this claim.

Now contrast that with something like slugging, which actually does have a solid dermatological foundation. If you’ve seen it online, slugging is where people apply a thick layer of petrolatum (like Vaseline) as the last step in their skincare routine to “seal everything in.” Unlike a lot of viral skincare hacks, this one is not actually new or experimental. Malave and James (2022) explain that petrolatum is one of the most effective occlusive moisturizers we have, capable of reducing transepidermal water loss by up to 98 percent. That basically means it’s extremely good at preventing moisture from escaping the skin.

Petrolatum forms a protective barrier over the skin, which helps lock in hydration and support the skin barrier. It can also be used in wound care for exactly this reason—it keeps the environment moist, which can support healing and reduce scarring. There’s even a technique called “soak and smear,” where damp skin is covered with petrolatum to maximize hydration and barrier repair (Malave & James, 2022). So, in this case, TikTok isn’t completely wrong—it just rediscovered an evidence-based dermatological practice.

Then we get to cryotherapy, which is probably one of the more dramatic-looking trends. If you haven’t seen it, it involves applying extremely cold air, usually around −110°C to −140°C, for a few minutes at a time. It’s often marketed as a way to improve skin tone, reduce inflammation, tighten skin, and even deliver anti-aging effects.

O’Connor, Wang, and Saedi (2018) reviewed the use of whole- and partial-body cryotherapy in aesthetic dermatology and found a major issue: there are very few controlled studies looking at actual skin appearance outcomes. Most of the research that exists is focused on things like muscle recovery, pain, or inflammatory markers, not cosmetic changes like wrinkles or skin texture. So, when people claim it “rejuvenates” the skin, that’s mostly coming from indirect physiological effects rather than direct dermatological evidence. Cryotherapy causes blood vessels to constrict and then reopen afterward, which can temporarily change how the skin looks or feels. But O’Connor et al. (2018) emphasize that there’s no strong evidence that this short-term phenomenon translates into long-term improvements in skin structure or aging. On top of that, the treatment itself isn’t tightly regulated. Protocols vary, and many of these services are offered in wellness or spa settings without medical oversight. While serious side effects are rare, risks like cold burns or frostbite can still happen if it’s not done properly.

So, while some TikTok skincare trends are loosely based on real dermatological practices, like slugging. Others, like beef tallow and cryotherapy, have interesting but not nearly enough evidence to support the trend. Make sure to always consult with doctors before indulging in any new skincare practices.

Written by Abigail Carleton

References

Russell M F, Sandhu M, Vail M, et al. (May 24, 2024) Tallow, Rendered Animal Fat, and Its Biocompatibility With Skin: A Scoping Review. Cureus 16(5): e60981. doi:10.7759/cureus.60981

Malave, G. S., & James, W. D. (2022). Petrolatum is effective as a moisturizer, but there are more uses for it. Cutis, 110(4), 175–176. https://doi.org/10.12788/cutis.0622

O’Connor M,  Wang JV,  Saedi N. Whole- and partial-body cryotherapy in aesthetic dermatology: Evaluating a trendy treatment. J Cosmet Dermatol. 2018;18:1435–1437. https://doi.org/10.1111/jocd.12821