Cistus during the pandemic

Editorial note (2026): This article is from spring 2021 and is a historical document from the pandemic. We have written about how we look back on that time and the research available then—much more soberly today—here: The story behind Cistus+ and Imun Guard.

Warm greetings from the Healing Garden in Tenerife!

We are right in the middle of our rockrose plantation. It is currently the best time to harvest, as the plants are just about to bloom and the leaves are now filled to the brim with resin and essential oils. Rockrose is fascinating for several reasons. In 2016, a study by the University of Regensburg showed that rockrose extract inhibits the replication of influenza, Ebola, and AIDS viruses in vitro. The study concludes that rockrose needs to be researched much more extensively, especially with regard to its effects in humans.

The structural problem is this: A purely plant-based preparation is relatively easy for anyone to produce and cannot be patented—it therefore offers no promise of a return on investment, which is why very little private research funding flows into it. This is not a conspiracy, but simple funding logic. Yet especially in view of the pandemic situation, this is precisely where public research funding would be needed. Rockrose is a promising and widely available plant whose potential is far from being fully utilized.

A small, placebo-controlled double-blind study with 160 participants showed that rockrose extract resulted in significantly fewer viral infections of the upper respiratory tract among the participants. This was only a small pilot study, but it was at least a start toward serious, scientifically grounded research. We then combined rockrose extract with cold-brewed green tea extract, black seed oil, and zinc. At the time, there was some initial research on the individual ingredients—importantly, review articles and hypothesis papers on the individual substances, not evidence of efficacy for our combination: a review of medicinal plants and viral diseases, as well as a hypothesis paper on Nigella sativa (black seed) and zinc.

Find out more about ingredients, research, and our experience with Cistus in our comprehensive Cistus overview.