The testing kit costs £69 and users will need to take a finger prick blood sample at home and then send it off to a lab.

Results are posted through Superdrug’s Online Doctor portal 24 hours after reaching the lab. If positive, it means the person had the virus at some point.

Some experts have urged caution over the test, with one saying that antibody tests for Covid-19 are ‘good for satisfying people’s curiosity but no more’.

But Superdrug said it was ‘confident’ in the accuracy and reliability of the test. It said the test detects the IgG, which is the protein that develops after infection.

Those who have recently developed symptoms should not take the test until at least 14 days as the antibodies may not be apparent before that point, Superdrug added.

Superdrug said the test has a sensitivity of 97.5%, meaning it will detect positive antibodies 97.5% of the time.

It has a specificity of 100%, which means that a positive result is specific to the SARS-CoV-2 virus – the novel coronavirus which causes the Covid-19 disease.

But the science behind the level of protection provided by antibodies is still in its early stages, as the virus has not been around long enough to know what level of protection any antibodies give.

Superdrug’s doctor ambassador, Dr Zoe Williams, said: ‘Receiving a positive antibody test result does not confer immunity, and it is important that people understand a positive test result does not mean you can be any more relaxed with the required hygiene and social distancing measures as set out by the Government.’

Dr Simon Clarke, associate professor in cellular microbiology at the University of Reading, said the presence of antibodies does not indicate that someone is immune, and that any post-infection immunity may dwindle rapidly.

He added: ‘These tests are good for satisfying people’s curiosity, but no more. We just don’t know enough about what it takes to make someone immune to Covid-19 to accurately test people.’

Martin Hibberd, from the London School of Hygiene and Tropical Medicine, said: ‘These new at-home tests promise to be quite popular, as people who have not had the opportunity to be tested wonder if they have had the disease.

‘However, these tests have not been evaluated in the format that they are being used (finger prick at home and posting to a laboratory for reading) so we cannot yet be confident in their sensitivity and specificity.

‘Despite this, I am pleased to see that the process includes a laboratory approach to reading the test, which should reduce the errors associated with doing this at home. And of course, a finger prick test at home is easier than visiting a clinic to give a more regular blood sample.’