Social media sites Instagram and Facebook are taking action over adverts in relation to weight loss products and certain cosmetic procedures.

The new policy means users can report such posts to the company, and action will be taken.

If a post promotes the use of certain weight loss products or cosmetic procedures, and has an incentive to buy or includes a price, it will be restricted to people over the age of 18.

While content that makes "a miraculous claim" about certain diet or weight loss products, and is linked to a commercial offer such as a discount code, will no longer be allowed and will be removed.

In a statement, Instagram says: "Our advertising policies have never allowed for the promotion of these products and now we are taking an extra step to address the growing trend of influencer marketing and organic content."

The Instagram logo is seen on a smartphone display | Image: Silas Stein/DPA/PA Images

The new policy is to be rolled out over the coming weeks.

It will see an additional functionality to allow people to report a post within the app if they believe it violates this policy.

If they see a post that they think violates the policy, they will be able to report it within the app and this will be reviewed by a team of content reviewers.

A spokesperson for Instagram says: "We want Instagram to be a positive place for everyone that uses it and this policy is part of our ongoing work to reduce the pressure that people can sometimes feel as a result of social media.

"We've sought guidance form external experts, including Dr Ysabel Gerrard in the UK, to make sure any steps to restrict and remove this content will have a positive impact on our community of over one billion people around the world - whilst ensuring Instagram remains a platform for expression and discussion."