New York, Jan 9 (IANS): The US Food and Drug Administration has warned against using self-collected throat swabs for home Covid-19 tests.

The warning comes after anecdotal reports of sore throats with coronavirus infection and early studies suggesting that saliva may be a better way to detect the Omicron variant, some people began taking antigen test swabs intended for nasal samples and using them to swab their throats, CNN reported.

The home test tweak took after after people began posting their results on social media with the hashtag #SwabYourThroat.

The agency cautioned that people should use the tests as instructed.

"FACT: When it comes to at-home rapid antigen #Covid19 tests, those swabs are for your nose and not your throat," it said Friday on Twitter.

Throat swabs are common in some places. In the UK, the National Health Service notes that some rapid tests for people without Covid-19 symptoms may require both a nose swab and a throat swab. But in the US, most self-tests require nasal specimens; a few involve saliva collected by spitting into a tube, the report said.

"The FDA advises that Covid-19 tests should be used as authorised, including following their instructions for use regarding obtaining the sample for testing," an FDA spokesperson was quoted as saying to CNN.

"The FDA has noted safety concerns regarding self-collection of throat swabs, as they are more complicated than nasal swabs -- and if used incorrectly, can cause harm to the patient. The CDC recommends that throat swabs be collected by a trained healthcare provider."