28 Nov 2023 Blackmores Long COVID: Low levels of circulating serotonin found in Long COVID patients 28 Nov 2023 Share Share on LinkedIn Share on Facebook Share on Twitter Share on Google+ Share on Pinterest News Responsible for almost 7 million deaths worldwide1, COVID-19 is the deadliest communicable healthcare outbreak of the 21st century.2 Among the hundreds of millions of confirmed cases1, it is estimated that approximately 10-20% go on to develop long COVID.3 Post COVID-19 condition, or long COVID, is a complex, multi-system illness characterised by either new or ongoing symptoms which last beyond 12 weeks of initially contracting COVID-19.3 × To continue reading this article, please Log In or Sign Up for access.