According to Mintel, 69% of Gen Z learn about beauty through TikTok. June’s TikTok trends have most definitely educated its users, of which the majority are Gen Z. From lessons on the bacteria that builds on makeup equipment and how to avoid this, to the techniques that prisoners use to achieve beauty looks in jail, here are the latest need-to-know viral trends on TikTok, selected by BeautyMatter:

Bacteria Testing: As strange as it may sound, this year, beauty consumers have become very interested in bacteria and mold. Back in February, countless TikTok users analyzed their cosmetic products, checking for mold and questioning the clean beauty movement. Brands including Kosas came under fire, with many users reporting finding mold in their concealer. Several cosmetic chemists defended the brands, explaining that mold often forms when consumers use products past their expiration date. Since then, consumers have become more self-aware of their beauty routines and how they can lead to hygiene issues. This month, as the trend of bacteria testing continues to rise, the attention has turned to beauty blenders and makeup brushes.

A popular video was posted by @pamelapedrozaa, which currently holds 9MM views and 550K likes. In the video, the content creator uses a Q-tip to take a swab of the surface of her beauty blender. Pedroza then takes a petri dish and wipes the swap across its base, leaving the dish for two days to see what grows during this time. When she returns to the dish, at least a quarter of it is covered with large fluffy bacteria, with the rest of the space heavily populated with spots of bacteria. Several other makeup gurus and influencers have tested the trend, including Huda Kattan, whose video has 4.7MM views. Kattan’s video is accompanied by audio that explains bacteria grows naturally on beauty application products, however, when not washed regularly, they can hold more bacteria than a toilet seat—leading to issues including acne and infections. Several creators have warned about the increase of these issues when people share their beauty blenders and brushes with friends, suggesting it's best to stick to your own products and wash brushes at least once a month.

Empty Eyeliner: TikTok has brought with it several eyeliner trends, from eyeshadow eyeliner to sleepy eyeliner; it seems a new trend surfaces every few months. The most recent technique taking the app by storm is empty eyeliner, comically dubbed “John Cena eyeliner” that is created using the less is more approach. Initially posted by @lenkalul (Lena Bagrowska), whose video now has 7.2MM views and 605K likes, the look is achieved by creating a smoky eye with any desired shades and blending it out to create a sharp edged shape that replicates where typical eyeliner would be applied. Once this is complete, users are instructed to take a Q-tip and makeup remover or micellar water, lightly dragging it across the lash line, and extend it to create the look of eyeliner. The technique does not actually use eyeliner, but instead carves out the shape a product would create by removing the previously applied eyeshadow. A thin brush is then used, along with concealer or foundation, to fill in the area, creating an empty, blank space effect. Many other users have also tried and tested the trend, including @mimiermakeup (2.1MM views), @molchanovamua (95.1K views), and @hayleybuix (199.6K views).

Jail Makeup: According to TikTok, prison inmates like to look their best too. However, due to strict rules on what can and cannot be taken or sent into prisons, many are left to experiment with whatever they can find to achieve their desired beauty looks. A video by @taylorbnice brought the trend to light, and gained 10.8MM views and 1.2MM likes  just four days after being uploaded. In the clip, the content creator gives a tutorial on how she did her makeup during the 17 years she served in prison. The video begins with baking flour in a bowl, followed by a Pepsi, and half a packet of cocoa mix whipped together to create a foundation-like texture. The creator then swatches the substance onto her arm, revealing extremely high coverage that entirely masks any blemishes and even a tattoo. The common “TikTok made me try it” phenomenon has taken over with this trend, as several beauty influencers and everyday consumers have begun to try out the DIY hack for themselves. @Mirayarios followed the steps presented by Taylor, adding extra flour to adjust the shade of makeup to her skin tone, with this rendition of the trend receiving 625K views and 22.5K likes. User comments have suggested other popular ingredients—including baby powder and coffee grounds—that can be used to achieve similar looks in prison.

@Taylorbnice’s video gained so much traction and support that viewers suggested Taylor begin her own makeup brand, this time using more skin-friendly ingredients. The community reaction to this viral video is yet another example of how beauty can improve the quality of life—as well as opening up business opportunities—for those who have served or are serving time in prison.

Scandinavian Hairline: Beauty is often influenced by different parts of the world, and this time Scandinavia is in the limelight. The search term “Scandinavian Hairline” has over 36.5MM views on TikTok, but what does it actually mean? A Scandinavian hairline is simply the look of baby hairs being lighter than the rest of the hair, named after Scandinavia because it is in these countries where someone's hair will often look this way naturally. Users from Denmark, Norway, and other Scandinavian countries have showcased their hair on the app, leaving others worldwide striving to achieve the look. In a video by @elblakee, which has 2.6MM views, the trend is addressed as the colorist recommends “painting the face,” a technique that includes separating a fine line of baby hairs and using bleach to paint on them in a downward motion. The end result is a significantly highlighted hairline compared to the rest of the hair—which looks even more striking when styled in a ponytail or a pulled back from the face. In addition to being shown on blonde hair, videos of the trend are surfacing on models with brown and black hair. While most are enjoying the trend, others have commented about the irony of trying to achieve this look: “Meanwhile, actual Scandinavians are telling y’all that their blonde baby hairs look bald in the light. But I'm glad you're enjoying it.”