"Do you have ferritin face?" a young woman asks on TikTok, pointing to dark circles, washed-out skin and brittle hair, alongside before-and-after style photographs. The content creator puts these features down to her iron levels.

It is one of a growing number of videos and posts on TikTok and Instagram claiming that low ferritin - a protein which stores iron in the body - can leave visible clues on your face.

Users list pale or grey-looking skin, dark under-eye circles, dry or cracked lips, hair shedding and weak nails, while others share portraits claiming stark visual differences.

The phrase "ferritin face" has spread widely across social media, with videos attracting millions of views.

But doctors say appearance alone cannot diagnose iron deficiency.

"Ferritin face is not a medical diagnosis," said GP Dr Aziza Sesay, who is based in the West Midlands.…