By Curro Cachinero, founder of Adaptonics · Based on more than 12 years of growing and processing our own crops in Tenerife · Last updated: August 2026
How Imun Guard emerged from an empty warehouse in the middle of lockdown
Sometimes a product story begins not with a business plan, but with a look at the inventory.
It was around March 11, 2020. I was sitting at Piet's in San Francisco and checking Adaptonics' inventory. That's when I noticed something strange:
Our entire annual supply of Cistus had sold out.
Rockrose was by no means our best-known product at the time. So why the sudden demand?
At the same time, events surrounding the novel coronavirus were unfolding rapidly. Europe began closing its borders. Spain was on the verge of lockdown.
I took the last flight back to Tenerife and arrived home during the night before Sunday—immediately before Spain closed its borders.
And then everything happened very quickly.
We had been working with Cistus for a long time. We knew the research on the polyphenols in rockrose and their interaction with various viruses. And Dr. med. Fritz Helmut Hemmerich, also known as Fridhu, had spent years studying salutogenesis, immunology, and how people can support their own resilience.
So we decided to take action.
In the middle of Spain's lockdown, we produced around 1,000 liters of Imun Guard from scratch.
Not as a luxury product. On the contrary: We deliberately offered the tincture at a significantly lower price than our other tinctures.
It was a pretty crazy undertaking in a pretty crazy time.
This situation also gave rise to Fridhus' video, on which this article was originally based.
Today, years later, the idea lives on. Our Cistus+ or Imun Guard tincture has been further developed. A slightly modified version is now also distributed through a Swiss pharmacy.
But what was the scientific idea behind it, exactly?
And above all:
Which of these is plausible—and which is actually scientifically proven?
Not fear or downplaying the risks, but self-efficacy
When we talk about viral diseases, we quickly find ourselves between two extremes: fear on the one hand and downplaying the risks on the other.
In doing so, something that is very important for our health can easily be lost: self-efficacy expectations.
This refers to the belief that we are not completely at the mercy of events, but can contribute to our own health.
That was precisely what Fridhu’s talk in spring 2020 was about. He described self-efficacy as a central factor in the interaction between the mind and the body. From the outset, the original video revolved around the question of what we ourselves can influence.
It was not about promising a miracle cure.
Nor was it about replacing medical treatment with a plant tincture.
The more interesting question was:
At what points can we influence the course of a viral infection at all?
In simplified terms, three levels can be distinguished:
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Does relevant contact with a virus occur at all?
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Does this contact actually result in an infection?
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Does an infection lead to illness—and how severe is its course?
That may sound banal at first. Biologically, however, these are different processes.
Viruses are not bacteria
A virus is fundamentally different from a bacterium.
Viruses do not have their own complete metabolism and cannot reproduce independently. To do so, they need cells from a host organism and use the host’s biological machinery for replication.
That is why antibiotics work against bacteria but not viruses.
With viruses, we need to consider different points of attack.
Can contact be reduced?
Can it be made more difficult for viruses to attach to or enter cells?
Can viral replication be affected?
And how does our immune system respond to cells that are already infected?
These questions are also important for understanding why plant compounds such as the polyphenols in rockrose have become interesting to researchers.
The first line of defense is surprisingly mundane
Many sensible measures are completely unspectacular.
Hygiene, good ventilation, and—depending on the situation—physical barriers can reduce the amount of virus we come into contact with in the first place.
Our mucous membranes also play an important role. The mouth, nose, and throat are key points of contact between our environment and our bodies.
This reflects a fundamental principle that runs throughout Fridhu’s entire talk:
Health does not always depend on a single spectacular active ingredient. Often, the surrounding conditions are at least as important.
“Strengthening the immune system” does not go far enough
One of the most popular phrases in naturopathy is:
We need to strengthen the immune system.
Biologically, this is a problematic oversimplification.
A good immune system does not simply have to react as strongly as possible. It must recognize, distinguish, and respond appropriately.
That is why, even in the talk at the time, Fridhu explicitly rejected the simplified notion that an immune system that is as “strong” as possible is automatically better. Instead, he spoke of an intelligent, adaptive, and regulated immune system.
An excessive immune response can be just as problematic as an insufficient one.
That is why it is more appropriate to speak of immune regulation or immune modulation.
Our immune system is not a muscle that can simply be trained to become ever stronger. It is a highly complex network of different cell types, messenger substances, and regulatory mechanisms.
The decisive question is therefore not:
How can I make my immune system as strong as possible?
Rather:
How can we support an organism in responding appropriately to a stressor?
Health consists of boundary conditions
Understandably, in medicine we like to look for the one active ingredient, the one medication, or the one mechanism.
However, a biological organism does not function in isolation.
Sleep, exercise, nutrition, metabolism, psychological stress, social relationships, and regeneration influence the conditions under which our organism functions.
Here too, more does not automatically mean better.
Too little exercise can be unfavorable. Extreme physical exertion can be as well.
Chronic stress is problematic. But constant underload can also affect our well-being.
The organism thrives through adaptation.
Hormesis: Stress and recovery
A limited stressor can trigger biological adaptation processes. This principle is known as hormesis.
Training is the simplest example:
We expose the body to a stressor, recover, and thereby become more adaptable.
Similar principles are being studied in time-restricted fasting, temperature stressors, and other forms of controlled stress.
What always matters is the relationship between stressor and regeneration.
A stressor that permanently overwhelms us is not hormesis.
And with that, we are already in the midst of a topic that is at least as important to Adaptonics as Cistus:
Salutogenesis—the question of how health arises and can be maintained.
And then there is Cistus
Why did Cistus in particular play such a major role in our thinking?
Cistus is rich in polyphenols. It was precisely these complex plant compounds that made it interesting to researchers.
Particularly intriguing was a possible effect that initially had nothing to do with the traditional idea of “strengthening the immune system”:
the direct interaction of Cistus extracts with virus particles.
A study published in Scientific Reports in 2016 examined Cistus incanus extracts, including against HIV-1 and HIV-2. In the cell model, the researchers found inhibition of infection and indications that components of the extract interfered with the initial attachment of virus particles to the host cell.
The same study examined experimental virus particles carrying envelope proteins from Ebola or Marburg viruses. Here too, inhibition was observed in the experimental model.
That is remarkable.
But the crucial words are:
in the experimental model.
This study does not prove that taking a Cistus tincture prevents or treats Ebola, Marburg, or HIV in humans.
It demonstrates a biological mechanism that makes further research interesting.
And this distinction is fundamental.
Plausible is not the same as proven
Fridhu placed great emphasis on this distinction as early as the original presentation.
He explicitly described the approaches under discussion as partly plausible, but not fully evident, and pointed out that the clinical gold standard—controlled studies in humans—was available only for certain areas.
We should therefore not simply divide scientific findings into “works” and “does not work.”
There are different levels of evidence.
1. Mechanistic plausibility
We understand a biological mechanism and have reason to assume that a substance could influence it.
This is interesting—but it is not yet evidence of efficacy.
2. In vitro research
A substance produces an effect on isolated cells or virus particles in the laboratory.
This makes it possible to study a mechanism in much greater detail.
But a human is not a petri dish.
3. Animal models
This examines whether an effect can be reproduced in a complete organism.
This takes us one step further, but it is still not clinical evidence in humans.
4. Clinical studies
Only here do we examine its actual use in humans.
And there are indeed clinical data on Cistus.
Cistus has also been studied in humans
A prospective, randomized, placebo-controlled study from 2009 examined 160 patients with upper respiratory tract infections.
CYSTUS052 and placebo were compared.
The subjective symptom score declined more over the course of the study with the Cistus preparation than with placebo. Differences were also observed in the inflammatory markers examined.
That is a substantially higher level of evidence than a purely laboratory experiment.
Another study compared CYSTUS052 with green tea in 300 patients with upper respiratory tract infections. There, too, the authors reported a greater reduction in subjective symptoms in the Cistus group.
These studies are interesting.
However, they do not automatically prove efficacy against SARS-CoV-2 or any other specific virus.
They investigated specific Cistus preparations for upper respiratory tract infections.
This precision is important.
Update August 2026: We are not aware of any newer placebo-controlled human studies on Cistus. These two studies from 2009 and 2010 remain the only clinical evidence to date—the developments of recent years have taken place exclusively at the laboratory and computational levels, as the next section shows.
March 2020: A hypothesis in real time
We need to go back to March 2020 once again.
Surprisingly little was known about SARS-CoV-2. Researchers worldwide were trying to understand how the virus enters human cells, which structures are involved, and where this process might potentially be influenced.
Fridhus's presentation and our decision to produce Imun Guard took place during precisely this phase.
One line of research focused on the molecular mechanisms of viral entry and possible ways to influence these processes.
Natural compounds and already known substances were also discussed as possible candidates.
A paper from this early phase of the pandemic examined natural substances and potential targets against SARS-CoV-2 in detail—from viral binding and entry into the cell to replication mechanisms and the immune response.
Source:
Potential roles of medicinal plants for the treatment of viral diseases focusing on COVID-19: A review
PubMed Central: PMC7367004
What interested us most was a research question we had already been exploring before COVID:
Could the polyphenols in rockrose influence the interaction between certain viruses and their host cells?
In March 2020, this was not an idea pulled entirely out of thin air.
Research on Cistus, influenza, and other enveloped viruses already existed.
This was not clinical evidence for COVID-19.
But it was a scientifically grounded hypothesis.
What was added later
Interestingly, it did not remain merely a hypothesis.
After the pandemic began, Cistus was also studied directly in connection with SARS-CoV-2 in the laboratory.
Researchers studied specific Cistus extracts in cell cultures and observed inhibition of viral replication or infection.
Later laboratory studies also included newly emerging SARS-CoV-2 variants (Alpha, Beta, Delta).
And research has continued since then—also beyond SARS-CoV-2:
In 2025, a Bulgarian research group showed that a Cistus incanus extract significantly inhibited both the replication and infectivity of free virus particles in two herpes simplex strains and a common-cold coronavirus (HCoV-229E). Notably, this also applied to a herpes strain resistant to the standard drug acyclovir—a particularly relevant area for finding new approaches in the face of drug resistance.
In 2024, an Italian research group also tested individual isolated compounds from the extract (including gallic acid, ellagic acid, and punicalin) directly against actual SARS-CoV-2 for the first time, rather than only against a milder substitute coronavirus as before. Punicalin showed a clear antiviral effect when both the cells and the virus were pretreated.
And in 2026, a purely computer-based modeling study (molecular docking) was published proposing possible binding sites for Cistus constituents on the Ebola virus protein VP40. This is explicitly not a laboratory or animal study, but purely a simulation—the most preliminary level of evidence conceivable, yet an indication that the question continues to be investigated.
In retrospect, this is interesting because one of the biological ideas that occupied us in spring 2020 has since been investigated experimentally several times—using new viral targets and more precise methods.
But this still applies here:
In vitro remains in vitro. And a computer simulation remains a computer simulation.
An effect in cell culture or on a computer screen does not make Cistus a clinically proven medication against COVID-19, herpes, or Ebola.
We want to draw precisely this distinction clearly.
A plausible hypothesis can be supported by subsequent laboratory research without automatically becoming a proven therapy as a result.
This is not a contradiction.
This is science.
The idea behind Cistus+ and Imun Guard
In the original presentation, Fridhu considered four components:
Cistus, black cumin, green tea, and zinc.
These four substances are explicitly presented together in the video. Fridhu himself characterized the available evidence as a mixture of laboratory studies, animal studies, and individual clinical data.
The idea was not to pour together four supposed “virus killers.”
The more interesting question was whether different biological approaches could complement one another.
Cistus
The focus was on the polyphenols and their experimentally observed interaction with viral surfaces.
Black cumin
Nigella sativa, and particularly its constituent thymoquinone, are the subject of numerous studies on inflammatory and immune processes.
Green tea
Green tea contains various catechins, including EGCG. These plant compounds have been studied for many years for their interactions with biological signaling pathways and various viruses.
Zinc
Zinc is an essential trace element and necessary for numerous immune system functions. In addition, zinc’s direct effects on various stages of viral replication processes are being investigated.
This gave rise to the basic idea behind Imun Guard or Cistus+:
not a single spectacular active ingredient, but combining several different biological approaches.
What we would phrase differently today
An article from spring 2020 must also be read as a document of its time.
At that time, scientific knowledge about SARS-CoV-2 was emerging practically in real time. Hypotheses, laboratory findings, clinical observations and political decisions were unfolding at a dizzying pace.
Some things that seemed plausible then are better understood today.
Some things have not been confirmed.
And for many things, good clinical data are still lacking.
That is why today we would phrase some statements more cautiously than we did in mid-March 2020.
One principle, however, has not changed:
Plausibility is not evidence. But plausibility is often the beginning of research.
After all, science does not begin with us already knowing the answer.
It begins with a good question.
From 1,000 liters during lockdown to today
When I look back on those weeks today, the story seems almost unreal.
A look at the inventory in San Francisco.
The entire annual supply of cistus suddenly sold out.
The last flight back to Tenerife.
Border closures.
Spanish lockdown.
And then came the decision, amid all this chaos, to produce around 1,000 liters of Imun Guard and deliberately offer the tincture at a significantly lower price than our other extracts.
This was not a normal product launch.
It was a response to an extraordinary situation.
Today, it has become something more lasting.
The formula has been further developed. Our Cistus+ or Imun Guard tincture is still available, and a slightly modified version is now also distributed through a Swiss pharmacy.
What has remained is the original idea:
Not mystifying traditional plants, but examining them with curiosity. Taking science seriously without pretending that we already know everything. And not turning people into passive spectators of their own health.
That is ultimately also the idea behind salutogenesis.
Not just to ask:
What makes us ill?
But also:
What helps us cope with challenges and stay healthy?
And it was precisely at this intersection of cistus, research, salutogenesis and self-efficacy that Imun Guard came into being.
What went through our minds during those weeks in spring 2020 was also captured in a five-part essay series—written directly from lockdown: Self-Efficacy, Stress and the Immune System, How Do You Kill a Hydra? On Antifragility and Health, A Sense of Coherence, Optimism Can Be Learned, and World Peace Is Decided in the Bedrooms.
Scientific sources
Kalus U, Grigorov A, Kadecki O, Jansen JP, Kiesewetter H, Radtke H.
Cistus incanus (CYSTUS052) for treating patients with an upper respiratory tract infection: A prospective, randomized, placebo-controlled clinical study.
Antiviral Research. 2009;84(3):267–271.
DOI: 10.1016/j.antiviral.2009.10.001
Kalus U, Kiesewetter H, Radtke H.
Effect of CYSTUS052 and green tea on subjective symptoms in patients with an upper respiratory tract infection.
Phytotherapy Research. 2010;24(1):96–100.
DOI: 10.1002/ptr.2876
Rebensburg S, Helfer M, Schneider M, et al.
Potent in vitro antiviral activity of Cistus incanus extract against HIV and filoviruses targets viral envelope proteins.
Scientific Reports. 2016;6:20394.
DOI: 10.1038/srep20394
Angelova P, Hinkov A, Gerasimova V, et al.
Antiviral Activity of Water–Alcoholic Extract of Cistus incanus L.
International Journal of Molecular Sciences. 2025;26(3):947.
DOI: 10.3390/ijms26030947
De Filippis A, D'Amelia V, Folliero V, et al.
Cistus incanus: a natural source of antimicrobial metabolites.
Natural Product Research. 2025;39(12):3396–3409.
DOI: 10.1080/14786419.2024.2335353
Molecular docking and molecular dynamics simulation of Cistus incanus compounds against the Ebola virus protein VP40.
Biophysica. 2026.
DOI: 10.3390/biophysica6020029
(Purely in-silico modeling; no laboratory or animal data.)
Potential roles of medicinal plants for the treatment of viral diseases focusing on COVID-19: A review.
PubMed Central: PMC7367004
About this article
This article is based in part on a presentation by Dr. med. Fritz Helmut Hemmerich (Fridhu) from early 2020. I edited his medical and biological line of thought for Adaptopedia, added the history of how Imun Guard came about, and placed it in a scientific context from today's perspective—including research that has been added since 2021.
Curro Cachinero
Adaptonics
This article is intended for informational purposes and as a historical record of our work. Laboratory findings or studies of individual Cistus preparations cannot be used to draw general conclusions about preventing or treating specific viral diseases.
The complete, scientifically contextualized overview of Cistus—including both placebo-controlled human studies—can be found in our comprehensive Cistus overview.