Cannabinoids and the endocannabinoid system in COVID-19 and long COVID: scoping review

Introduction and clinical context

COVID-19, caused by the SARS-CoV-2 virus, left as a legacy a persistent clinical challenge: so-called long COVID, a set of symptoms that persist for weeks or months after the acute phase of the infection — fatigue, brain fog (difficulty concentrating and remembering), pain and sleep disturbances. Much of these symptoms have been associated with inflammatory processes and dysregulation of the immune response. In this context, researchers began to investigate the role of cannabinoids and of the endocannabinoid system as a possible object of study, given their involvement in the regulation of immunity and inflammation.

Methodology and findings

This work is a scoping review: unlike a clinical trial, it maps and organizes the existing literature, identifying what has already been studied and where the gaps are. The review gathered hypotheses and preliminary studies on the interaction of phytocannabinoids with SARS-CoV-2 infection and with long-COVID symptoms. The central finding is cautious and honest: the evidence is still emerging and heterogeneous, and there is, so far, no approved indication of medical cannabis for COVID-19 or long COVID. The value of the study lies in consolidating the state of the art and guiding future research with methodological rigor.

Mechanism of action and safety

The scientific interest rests on the endocannabinoid system, which takes part in immune and inflammatory modulation. Hypotheses under study link the CB2 receptors — present in immune-system cells — to the possible attenuation of the so-called "cytokine storm" and of neuroinflammation, processes linked to symptoms such as fatigue and brain fog. It is essential to stress that this is an investigated mechanism, not proven efficacy. Any use of cannabinoids should consider drug interactions and individual contraindications, under medical assessment, avoiding self-medication.

Regulation in Brazil (Anvisa)

In Brazil, access to cannabis products is regulated by Anvisa, especially through RDC 660/2022 (patient import with a medical prescription) and RDC 1,015/2026 (new manufacturing and import framework). As there is no established indication for long COVID, any use would be off-label and depends on medical judgment and prescription. This content is informative and scientific and does not replace the guidance of a healthcare professional.