Examples include applying bleach to whiten teeth, removing moles at home, and using eyelash glue to make lips appear larger, BBC News has discovered.
When these videos went viral, they encouraged others to copy the so-called "beauty hacks", which could cause permanent harm, the groups warned.
TikTok told BBC News the videos did not violate its community guidelines.
However, the British Association of Dermatologists, the British Dental Association and the British Skin Foundation - who viewed the videos - have today issued warnings about copying these treatments on social media.
"It is important to remind people that social media should not be used as a primary source for dermatology issues," the British Association of Dermatologists said.
"When it comes to skin, it can lead to unnecessary fear or panic where it is not needed, wasting of resources such as money on products unable to treat medical problems, potential delay in treatment, as well as potentially worsening one's psychological health.
A government spokesperson for the Department of Health and Social Care said it was "concerned by reports of dangerous and misleading cosmetic beauty 'hacks' circulating on social media."