What over the counter (OTC) products have been evaluated for anxiety in adults aged 18-60? A scoping review.

Background: Anxiety symptoms and disorders are common in the UK. Whilst waiting for, or alongside, treatments such as anxiolytics or psychological therapies, people often self-manage anxiety symptoms with products purchased over-the-counter (OTC), such as herbal medicines or dietary supplements. However, the evidence for these products is often presented across different reviews and is not easy for patients or healthcare professionals to compare and understand.

Aims: To determine the nature and size of the evidence base available for these products.

Methods: A scoping review. CENTRAL, MEDLINE, EMBASE, PsycInfo, and AMED (inception-Dec 2022) were searched for RCTs assessing OTC products in people aged 18-60 with symptoms or a diagnosis of anxiety.

Results: In total 69 papers assessing a range of products were found, which mostly focussed on kava, lavender, saffron, probiotics, Galphimia glauca and valerian. Studies used varying dosages. Compared to herbal medicine studies, there were much fewer dietary supplement studies and homeopathic remedy studies, despite some of use of these by the general public.

Conclusion: Future research needs to investigate commonly used but less evaluated products (e.g. chamomile, St John's Wort) and to evaluate products against or alongside conventional treatments to better reflect patient decision making.