TikTok's recent trend nicknamed the 'candle back massage' claims to ease sore muscles using an ancient pain relief technique.
Suction is then created and the glasses can glide across the back - with the candle still inside - to target area where muscles might be tight.
Videos on TikTok show girlfriends doing the massage on their boyfriend's backs.
Although it is currently trending on TikTok, the massage technique has been seen in videos on the app in 2020.
And even beyond 2020, the massage has long predated social media. The trend stems from cupping massages which go as far back as Ancient Egypt where it was mentioned in old medical texts from 1550 BC.
Cupping is part of several ancient healing systems including Chinese and Korean. Nowadays, it is offered by practitioners of Traditional Chinese Medicine.
The method usually does not involve leaving a candle in a glass as seen on TikTok, but rather uses burning alcohol, herbs or paper. The heat is removed from the cup before it is placed onto a person's skin.
The cupping method increases circulation which helps relieve muscle tension, encourage cell repair, and also reduce the appearance of cellulite.
There are several variations to cupping including dry cupping which only uses suction, bleeding cupping which involves controlled medicinal bleeding, and flash cupping where there is repeated and quick suction and release.
The recent TikTok trend is most similar to running cupping where the suction cups are moved across the body with oil.
Cupping previously hit headlines during the 2016 Olympics when swimmer Micheal Phelps and other athletes could be seen with several small circular bruises on their bodies.
Although relatively simple to do at home, cupping should not be done on skin that is sunburnt, on areas with open wounds, or on skin ulcers. It is recommended to only have the massage performed by a professional.