What’s The Significance Of Red LED Lights On TikTok?

When a term, topic, or activity trends in TikTok videos, those who spend lots of time on the platform know exactly what the fuss is all about.

Casual TikTok users may not understand the trend’s meaning, but there’s little doubt in the minds of people who spend hours surfing their feeds every day. It’s rare that two similarly-named TikTok trends involve two very different topics.

Red LED lights, however, are the exception to the rule. The lights began appearing widely in TikTok content in 2021 because of something called the Silhouette Challenge. And in late 2024, another red LED TikTok trend emerged on the social media platform, but this one deals with health and skin care.

Let’s explore.

Red LED Lights to Set the Mood on TikTok

There’s a long history of red light implying or symbolizing sexual activity. Ever since the 19th century (and some historians believe, much earlier), “red-light districts” have been known as areas where prostitution and sexually-oriented businesses have been concentrated.

Meanwhile, color psychologists tell us that red triggers the strongest emotions of any color on the spectrum, very often associated with love, passion, and desire. In fact, research has shown that male subjects find the same females more attractive and sexier when they’re dressed in red than when dressed in colors like blue.

Those underlying emotions led to what was known as the Silhouette Challenge on TikTok. TikTok content creators began posting videos showing what they visualized as the ultimate intimate atmosphere; most used red LED lights to create a sensual and sexually-tinged look as they posed in a doorway, in (as you’ve probably guessed) silhouette.

The trend calmed down, however, once a flurry of TikTok posts revealed how to remove the red filter that produced the effect — showing the creator in all of their not-necessarily-sexy glory.

Red LED Lights for Skincare Therapy

This longer-lasting trend is still going strong on the app.

It involves the use of red-light therapy masks and lamps to purportedly help rejuvenate skin and provide anti-aging benefits (or at least, the appearance of reduced aging). The devices use red and near-infrared light to penetrate the skin and supposedly stimulate cellular activity; the technique’s popularity has soared during the 2020s.

The TikTok trend focusing on red-light therapy started in 2024 with users discussing the pros and cons of the approach to skincare, but it evolved into a flood of unboxing videos, tutorials, user testimonials, and similar content.

Both trends are based on the use of red light, but seem to have nothing else in common. If you stop to think about it, though, the bottom line for each involves physical (and perhaps sexual) attractiveness — so maybe they’re more closely related than would first appear.