TikTok is rife with influencers warning of “ferritin face”, a term they use to describe the pallor, dark circles, dry skin, and hair loss claimed to indicate low iron stores. But is this based on fact or fiction, and when is it time to head to the GP?What is ferritin?Iron is not made in the body, so typically we consume it in our diet.

Ferritin is the protein responsible for storing iron in the body, particularly in the liver, and releasing it in a controlled manner.By measuring ferritin levels, which can be checked via blood tests, it is possible to get an snapshot of the body’s iron reserves, although experts warn such levels are not always a reliable guide.Blood ferritin levels of less than 30 micrograms/L indicate an iron deficiency, according to guidelines from the National Institute for Health and Care Excellence.However “a level below 50 might be a pointer of iron deficiency,” said Sue Pavord, professor of practice in medical haematology at Oxford University hospitals.Can low ferritin change a person’s appearance?The symptoms influencers describe include dark circles under the eyes. Photograph: Alamy/PAThe symptoms influencers describe, such as dark circles under the eyes, grey skin, cracked lips and hair loss, can be caused by a variety of factors, including genetics, stress and dehydration.

But experts say low iron stores can have an effect.“Iron is needed for every single cell of the body. So if you are iron deficient, you will be very fatigued, have brain fog, your skin will look dull and saggy, you’ll look pale and tired,” said Pavord. “While we can’t diagnose iron deficiency from the face, it might be a suggestion that there is iron deficiency.”Prof Toby Richards of the University of East London and the Iron Clinic added such changes were particularly pronounced in people with very low iron stores. “They tend to be the really sick patients,” he said.Why might people have low ferritin?“Periods and pregnancies are the most common [causes],” said Pavord, but others include not getting enough iron – either from dietary choices or because of poor absorption, as can occur with coeliac disease.Low ferritin levels can also arise as a result of blood loss linked to gastrointestinal problems, such as gastritis or polyps.“We also sometimes see it in athletes because of the high demand for iron on their bodies,” she added.What should people who are worried they might have low ferritin do ?Richards said those who are at high risk of low ferritin – such as people who have heavy periods, are pregnant or have had children, or are vegetarian or vegan – should ask for a blood test, adding that should include a full blood count, ferritin level check, and test for levels of B12 and folate.“This is a proper disease, and to put it into perspective, it’s the leading cause of disability in women of reproductive ability,” he said.Pavord also said those who are concerned about their ferritin levels should ask for a blood test, adding it was important to understand the cause of iron deficiency.“Older people suspecting iron deficiency would need a proper clinical assessment and investigations to look for a source of bleeding from the bowel,” she said.Pavord said it is possible to buy iron tablets over the counter at a pharmacy.“Taking iron tablets without confirming iron deficiency is not really going to do you any harm, particularly if you’re a young woman, because you’re losing a lot of iron with periods,” she said.But Richards noted many products do not necessarily contain the appropriate dose. “If you are iron deficient, you need to be on a full treatment dose … and then repeat your blood results in three months’ time,” he said. “What’s marketed is normally the lower dose supplementsPavord was positive about the increase in awareness.“We need to stop normalising iron deficiency,” she said. “Many women are just exhausted trying to cope with their periods, cope with their pregnancies, cope with their young children and their busy jobs, and we need to stop normalising fatigue.”Richards agreed. “ Anything that raises the plight of women in this area is a good thing,” he said.However Dr Asiya Maula, a GP from the private firm The Health Suite, was cautious. “The risk with social media trends is that people may see themselves in a list of symptoms and assume they have a deficiency without checking whether that is actually the cause,” she said.