Social media users have claimed that nasal swabs used in COVID-19 tests contain lithium. However, there is no evidence to back that up, and the U.S. Food and Drug Administration (FDA) has denied it altogether.

Lithium is used as a mood stabiliser to treat bipolar disorder. Side effects can include nausea, diarrhoea, dry mouth, hand tremors and drowsiness (www.nhs.uk/medicines/lithium/). Those who take it have their blood assessed regularly for levels of the drug.

However, in one social media post, a user claims (here “The PCR/lateral flow test swabs are made of hard materials and contain a variety of (nano) particles made of silver, aluminium, titanium, glass fibres, ethylene oxide and lithium, many of which are undeclared in the package leaflet […]

“When the swabs enter the mucous membrane, they can cause wounds and inflammation and cause severe damage to the blood brain barrier.”

Reuters has previously addressed reports that PCR tests can touch or damage the blood brain barrier (here and here).

Reuters has also fact checked claims regarding the use of ethylene oxide in COVID-19 test nasal swabs, finding the amount used is safe (here).

There is also no evidence that nasal swabs contain particles of lithium.

“Nasal swabs used to test for COVID-19 do not contain lithium,” an FDA spokesperson told Reuters by email. “The [U.S. Centers for Disease Control and Prevention] CDC recommends that upper respiratory samples for COVID-19 diagnostic testing should only be collected with sterile swabs that may include flocked, foam, spun polyester (e.g., dacron), and spun rayon tipped swabs.”

The spokesperson added that the types of swabs validated for use for over-the-counter home-use COVID-19 tests “can be found under reagents and materials in the authorized labeling”.

Meanwhile, Britain’s Medicines and Healthcare products Regulatory Agency (MHRA) told Reuters it is “unlikely” that lithium is present in the country’s COVID-19 test swabs.

“MHRA does not hold specific information relating to the materials used in sample collection swabs, however we can confirm that the absorbent tip of the sample collection swab is often a nylon fabric,” they added.

Approved medical devices, which have a ‘CE’ or ‘UKCA’ mark on their packaging, have followed the requirements of the medical device regulations and are considered safe to use, the spokesperson told Reuters.

The MHRA also issues Exceptional Use Authorisations (EUAs) in exceptional circumstances, allowing medical devices to be used that have not followed the standard approval process. However, it only issues an EUA, “once we are satisfied the applicant has provided sufficient evidence that their device’s performance is suitable for use and can be used safely by the intended user”, the spokesperson said.

A list of medical devices given exceptional use authorisations shows all medical devices granted the exemption by the MHRA during the COVID-19 pandemic (here).

The FDA and MHRA also document the tight regulatory frameworks and international standards adhered to for medical products given EUAs during the COVID-19 pandemic (here, here).

“The components of any medical test are always rigorously checked for safety,” said Dr. Alexander Edwards, associate professor in biomedical technology at the University of Reading (here).

Dr. Edwards told Reuters: “I am not aware of lithium being used in swabs, or in the manufacturing of swabs. However, if lithium was toxic it wouldn’t be allowed in swabs.

He said that, unlike consumer cotton swabs, diagnostic medical swabs are “much more carefully prepared and the components must be rigorously screened to make sure they don’t contain anything that might mess up the test”.

Dr. Edwards added that a source of confusion might be the use of “Lithium Heparin” in some blood collection tubes.

Lithium heparin is an anticoagulant used for chemical measurement in blood or plasma tests. A small amount is routinely used in blood collection tubes to stop blood clotting before it is analysed.

As seen in healthcare provider fact sheets, several COVID-19 antibody tests given emergency approval by the FDA contain “lithium heparin” in a list of specimen types that can be tested (here, here, here, here).

“The COVID-19 antibody test labeling will list all of the sample types authorized for use with the test,” the FDA spokesperson told Reuters.

However, COVID-19 antibody tests do not contain lithium heparin, they said.

Any lithium heparin used in the detection of antibodies is not in the test itself, but in the collection tubes that the lab uses to collect the sample, the FDA told Reuters.

Dr. Edwards said that even when lithium heparin is present in antibody diagnostic test tubes, tube contents would not come into contact with a patient, as blood collection tubes are not involved in swab tests for COVID-19.

Chris Denning, Director of the University of Nottingham Biodiscovery Institute (here), affirmed Dr. Edwards’ comments.

He told Reuters that even if lithium was present in swabs, “the key points are what concentration, how much of this actually enters the body (i.e. what is the effective serum concentration) and whether any side effects consistent with lithium use are experienced. Any molecule is toxic, it’s simply a question of dose”.

Denning added that when prescribed, the typical starting dose of lithium is adjusted based on serum-lithium concentration in the body to ensure the dosage is not toxic.

“Unless there is real evidence that lithium is present [in COVID-19 swabs] AND it reaches serum levels that are clinically meaningful AND there are notable clinical outcomes or side effects, then there is no credibility to these claims,” he said.

The claims appears to be resurfacing the findings of a Slovakian report, which has been shared on websites that frequently shared misinformation (here).

The alleged study claimed test sticks were analysed in an unnamed hospital laboratory in Bratislava between November 2020 and March 2021, finding lithium and “Darpa Hydrogel” on the swabs. It added that the findings were “confirmation of genocide”.

However, Reuters could not find examples of the study published in reputable academic journals.

No evidence. The FDA told Reuters lithium is not present in COVID-19 tests. There is no evidence the ingredient is present in diagnostic test swabs. Lithium heparin is used in antibody test collection tubes, which would not come into contact with a user.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.

Our Standards: The Thomson Reuters Trust Principles.

All quotes delayed a minimum of 15 minutes. See here for a complete list of exchanges and delays.