The UK Parliament's Science and Technology Committee has argued social media firms have a legal "duty of care" to children.
Social media has facilitated bullying and online grooming of children, according to a new report by the committee, which called for the introduction of a regulator.
The report has been welcomed by the Royal Society for Public Health, whose director of external affairs, Duncan Stephenson, provided evidence to the Science and Technology Committee.
He explained: "We fully support the select committee calls to help researchers and others to better understand the long-term effects ... to our wellbeing."
Andy Burrows, from the children's charity NSPCC, has also called for changes.
He said in a statement: "For far too long social networks have been allowed to operate in a Wild West environment and put children at unacceptable risk.
"The government now has a crucial opportunity to set out a comprehensive plan to protect children online. This must include an independent statutory regulator with enforcement powers, that can impose strong sanctions on platforms that fail to keep children safe."
As part of its report, the Science and Technology Committee surveyed more than 3,000 young people.