What Does Research Show for CBD's Effects on the Immune System for Viral Infections?

CBD and immune response to viral infections


First, an important point.  The FDA has not approved or tested CBD for coronavirus or Covid19.  We're only going to look at pathways affected by CBD on immune response to viral infection in research only.  


We've seen reports of CBD having both antibacterial and antiviral effects. 


Now's definitely the time to do the deep research on this.


What prompted the push was a curious thing we noticed over the past 2 months.


My spouse takes 300 mg of CBD a day (research shows max dose for neurogenesis).


She avoided about 3-4 different colds and cases of flu that the rest of the family was saddled with for a few months.


We were crammed in a hotel room over winter break and she had none of it!


A few coughs now and then or a minor feeling like she was fighting something off but nothing close to what the other 3 family members had.


Was this just happenstance or anecdotal?


If you've read any of our reviews of CBD and anxiety or CBD and perimenopausal symptoms, you'll know that we don't mess around with anecdotes.


What does the research say for CBD and viral infection?


We'll cover the following topics: 

  • How viruses infect us and cause illness - A quick primer
  • CBD's effect on our immune response to infection
  • Research on CBD's effect on viral response
  • CBD's effect on the HIV viral aspects (i.e. the new Gilead medication)
  • CBD and the ACE2 receptors
  • Other anti-viral supplements with NIH research backing them


Aside from CBD, we'll look at some potentially safe and effective antiviral supplements with real NIH research backing them towards the end.

We also have two extensive reviews on possible game changers which we'll touch base on in their respective sections. 


Let's get into it!

How viruses infect us and cause illness - A quick primer

First, a virus acts like a little piece of genetic machinery.  Not quite alive as it needs a host cell to make more of it.


Once it gains entry, it uses chemical keys on the outside of its shell to gain access to our cells.


It then hijacks our cellular machinery to make copies of it which get released out into our body to continue the process.


You can see how this quickly gets out of control and overruns our body.


That's a very simplified explanation but does the trick.


There are really three stages to look at from our point of view (the attackee): 

  • Binding to the cell
  • Replication of more virus
  • Release of more virion (the little individual particles of virus)


A few interesting notes.


Ever wonder why viruses generally seem to swell up in the winter?


The "shell" of the virus becomes stronger with drops in temperature: 

At winter temperatures, the virus’s outer covering, or envelope, hardens to a rubbery gel that could shield the virus as it passes from person to person, the researchers have found. 



This protective coat goes away in the warmer summer seasons which makes viral survivability harder!


And yes...we're all inside within enclosed places during the winter which doesn't help.


The rate of replication and our immune response to that rate are critical to viral infections and their potential danger.


As researchers found from the 1918 deadly flu pandemic, our immune's overactive response was partly to blame: 

But in some cases, an infection can trigger a reaction so destructive it can be fatal. Scientists call this a cytokine storm, because of the violent way immune cells respond to a virus.  



Cytokines are members of our immune system response (see CBD and inflammation or CBD and neuroinflammation).


Let's go there now since our immune system's over-reaction may be critical to why one virus goes away while others can kill.

Our immune's response to viruses 

Our immune system is way too complicated to get into here but we can dance around the edges specific to viral infections.


As we saw above, what killed many people with viral infections is not the virus itself but our own immune system's response.


There are initial steps the body will take against infection such as an increase in body temperature or a drop in tryptophan.


Increase temperature slows down viral replication and affects our immune response


We covered the tryptophan connection at our Tryptophan, inflammation, and anxiety or depression article since a drop there also drops our serotonin.


This is partially why your mood can drop when you're sick.


The body is trying to starve out the protein, tryptophan, a virus or bacteria needs to make more of themselves.


Beyond that, you have the full force of the immune system response.


Part of this is innate or built into the system.  The other part is adaptive which the body learns from experience with prior viral interactions.


That's the basis for vaccines.


There are some key players to look at without getting too complicated: 

  • T Cells - Generals of the immune system
  • Macrophages - literally eat the viruses and should be excreted (such as when you blow your nose)
  • NK cells - natural killer cells


The immune's system basic approach is to detect infected cells and initiate cell death (called apoptosis).


Interestingly, this process is partially under the direction and control of the endocannabinoid system where CBD has its impact!


We all have this system and it's tasked with balancing other key systems: 

  • Endocrine system - hormones
  • Nervous system -neurotransmitters
  • Immune system - cytokines, macrophages, T Cells


So right in the wheelhouse of viral response.


There is a large body of evidence from in vivo and in vitro models showing that cannabinoids and their receptors influence the immune system, viral pathogenesis, and viral replication.  



Homeostasis is the key there with immune response.


That's just a fancy word for balance.


We want an increased response to infection early in the process while also preventing too much collateral damage and response to where we're killed along with the virus.


Viral replication rates are key here.


Some viruses such as the H5N1 virus have very high replication rates and our immune system panics.


Scorched earth.


Let's look at CBD directly with an addendum on THC (very different effects).

What does CBD do for the immune response 

CBD has shown powerful effects to calm the immune response but is that the wrong direction with viral infections?


Here's the fascinating piece...CBD's effects appear to change depending on the state of the system.


Most of the research is looking at situations where the immune response is too high: 


What about the opposite...situations where the immune system needs to fire up but not go out of control?


After spending a few 1000 hours in NIH research and writing a few 100 thousand words on the subject, an interesting facet of CBD surfaces.


Its effect is not one-directional.


Take cancer for example: 

  • Healthy cell with low inflammation - CBD will not affect inflammatory levels
  • Healthy cell with high inflammation - CBD will reduce inflammation
  • Cancerous cell - CBD will INCREASE inflammation


Read that back over again because it's nothing short of revolutionary.


Most substances will push in one direction indefinitely.


Benzos (for GABA - see CBD versus Benzos) or SSRIs for serotonin (see CBD versus SSRIs) are perfect examples.


With a higher dose, they just keep increasing the levels....to a point where it can be dangerous.


That's why CBD doesn't cause sedation/overdose with GABA or Serotonin syndrome with serotonin.


CBD acts as a constraint on various systems under endocannabinoid system regulation.


On both the low and high end.


THC is different.  


THC pushes in one direction on the CB1 receptor (our primary endocannabinoid receptor).


In terms of viral infection, the research is not positive for THC which is immunosuppressive regardless of the system's needs: 

For HSV-2, HIV-1, KSHV, influenza, and VSV viral replication, or surrogate measures of infection, were found to be substantially increased upon cannabinoid treatment. 



This is not good and THC should be avoided during viral infection.


They were testing THC in those situations which was the dominant "cannabinoid" until the last few years.


What about CBD and immune response to viruses?


In general, CBD calms the immune response during periods of inflammation.


Keep in mind that inflammation is just code for a heightened immune response which we want at the onset of viral infections.


This is why we see its effects on the "damage" side from infection: 

Together, our findings highlight the anti-inflammatory effects of CBD in this viral model of MS. 



There are many studies from sepsis to stroke where CBD is able to help calm the immune response to damage and improve function.


One example that's relevant here is a study on lung function after exposure to infection in mice: 

The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. 



That's a veritable list of inflammatory agents.


It's autoimmune with a bang!


Let's look at studies on CBD directly with various viruses to ensure it doesn't suppress our immune response when we actually need it.

Can CBD help with viruses

CBD's real benefit may be on the high-end immune response as we saw with MS: 

Moreover, CBD administration at the time of viral infection exerts long-lasting effects, ameliorating motor deficits in the chronic phase of the disease in conjunction with reduced microglial activation and pro-inflammatory cytokine production. 



That being said, there are other key points of effect.


Remember how the immune system uses cell death to get rid of infected cells?  It's called apoptosis.


CBD has a direct effect there (as with cancer cells): 

While CBD induced dose-dependent apoptosis in both cell types, at 0.25 to 1.0 µM, CBD induced significantly more cell death in the virus-infected HMVECs than in the mock-infected HMVECs. 



This is important.  When they added CBD, there was an increase in cell death for virally infected cells (but not healthy cells).


This "selective" effect is key when the immune system is on a warpath.


As they state: 

These dose-response data indicate that endothelial cells infected with KSHV are more sensitive to CBD-induced apoptosis than mock-infected endothelium and suggest that at specific concentrations, CBD may preferentially kill Kaposi sarcoma tumor cells versus normal endothelium. 



Again, they used a virus to initiate damage to the cells.


What about viral replication?


The only research we could find was for viral hepatitis: 

CBD inhibited HCV replication by 86.4% at a single concentration of 10 μM with EC50 of 3.163 μM in a dose-response assay.  



What about interferon, one of the medications that are showing some promise against viruses?


We know it well from decades of studies for HIV.  Interestingly, HIV medications are showing some potential against coronavirus.


Why is interferon important?

Virally infected cells produce and release small proteins called interferons, which play a role in immune protection against viruses. Interferons prevent replication of viruses, by directly interfering with their ability to replicate within an infected cell. 



Studies on chronic inflammation and autoimmune have shown that CBD can suppress interferon.


Do the "biphasic" dual effects also apply here when interferon is needed (such as with a viral infection)?


Another study looked at HIV (a different type of viral infection): 

THC (but not CBD!) suppressed secretion of IFN-α by pDC from both healthy and HIV+ donors, arguing that although THC may impair antiviral responses, this may also be protective in neuroinflammation associated with prolonged HIV infection. 



IFN is short for interferon and CBD had a completely different effect there with a viral infection (HIV in this case).


Again, THC is not a good fit for viral infections like the SARS family of viruses or influenza which are fast, acute, and explosive in the body.


CBD did not suppress the key immune responders (IFN).


Again, this is the endocannabinoid system which is tasked with righting the ship across the immune system.


There is a time and place for interferon to spike.


We can't put it any better than researchers did here: 

Third, our previous study demonstrated that CBD either inhibited or enhanced IL-2 and IFN-γ production in response to optimal or suboptimal T cell activation, respectively [23], demonstrating that cellular activation dictates the CBD response.



IL-2 is one of those cytokines used by the immune system to fight infection.


Its role: 

IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". 



Let's tie those pieces together.


T cells are the generals of our immune system which basically scan for intruders (virus) and rally the troops.


If you read the above NIH study, CBD either slowed immune response (IL-2 and IFN-y production) when it was strong or enhanced it when it was low.


When T cell activity is too strong, it will actually suppress that activity (which is key to autoimmune and inflammatory states).


Levels of T cells in the lungs are important for the new class of SARS viruses: 

Interestingly, the acute phase of SARS in humans is associated with a severe reduction in the number of T cells in the blood. 



Now, do you see why we geek out so much on CBD?


This is our immune system, a ridiculously complicated patchwork created over 100's of millions of years as an artifact of an arms race against a sea of foes.


  • Autoimmune medications suppress immune function
  • Antiviral medications jack up immune function


None of them will respond according to the needs of the system.


That's why side effects can be so nasty at either extreme.


Again, THC's effect is one-directional: 

Treatment of mice with Δ9-THC resulted in persistent inhibition of IL-2 production even 7 days post cannabinoid treatment. 



IL2 is literally part of the system that detects the presence of a virus... a friend from foe.


Probably, the best listing we've seen of both CBD's immune-suppressing (in states of inflammation) or immune-boosting (in states of infection) can be found here: 



Toward's the end is a chart with immune-enhancing studies.


It's an impressive review (we're jealous).


We mentioned how T cells dropped in the acute phase of SARS.


This is a fascinating result that points directly to the lethality of these viruses.


Let's go there now.

CBD and the HIV aspect of the new SARS viruses

HIV is a fascinating (albeit heartbreaking) type of virus in that it specifically targets the generals of our immune response...T Cells!


Wolf in sheep's clothing.


They disarm the very cell designed to protect us against them.


There's an interesting fact with the new breed of viruses (SARS, MERS).


Studies on the SARS virus showed a significant "suicide" (apoptosis from above) or drop in T cells during the critical period of the disease:

The effector phase of an immune response is followed by a sharp contraction in the number of antigen-specific T cells, with 90–95 % of virus-specific T cells undergoing apoptosis. 



This is odd since T cells should be increasing, not committing cellular suicide.


This brings up how HIV drugs may have the promise to work with the SARS viruses.


Researchers have even pinpointed the shared mechanism: 

This study points to a similar mode of action for the two viral proteins, suggesting that anti-viral strategy that targets the viral-induced membrane fusion step can be adopted from HIV-1 to SARS-CoV. 



Basically, they're saying the new strains of coronavirus share some similar pathways to HIV. 


Whether this was "engineered" is above our paygrade but the location of  Wuhan and China's only level 4 lab is curious at best.


Meanwhile, the link between HIV proteins and the new coronavirus are equally present: 

We found 4 insertions in the spike glycoprotein (S) which are unique to the 2019-nCoV and are not present in other coronaviruses. Importantly, amino acid residues in all the 4 inserts have identity or similarity to those in the HIV1 gp120 or HIV-1 Gag. 



Those medications revolve around blocking an enzyme called protease which viruses need to replicate.


Seeds and roots are high in those naturally (as a natural defense).


Chickpeas, soybeans, seeds, etc.


The HIV medication currently being explored is Remdesiver, an antiviral developed by Gilead for Ebola and other viruses.


Its mechanism is to act like adenosine but with a slightly altered structure, which confuses the virus replication process.


We did a full review at our How does Remdesivir work for coronavirus article since it's fascinating.


That's one of the potential options but it's a little bit further out.  We'll touch base on the other below.


Back to this pathway.


Are there other ways to naturally boost this system but without the side effects? 

CBD increases brain adenosine levels by reducing adenosine reuptake. Increased adenosine is associated with neuroprotection and decreased inflammation after brain trauma. 



We would love to see research on whether CBD can offset some of the side effects of remdesivir by supporting that pathway.


Another study pointed to this pathway for CBD's anti-inflammatory effects: 

These studies demonstrate that CBD has the ability to enhance adenosine signaling through inhibition of uptake and provide a non-cannabinoid receptor mechanism by which CBD can decrease inflammation. 



On to the really different aspect of the new SARS class of viruses.

SARS viruses and the ACE2 Receptor connection

There's an interesting piece of information coming out of current research.


Let's do a quick walkthrough.


We have a system that controls the tightening and loosening of our cardiovascular system.


The tightening agent is called angiotensin.  It comes in two flavors and one has been made popular with blood pressure meds.

  • ACE2 inhibitors (Angiotensin conversion enzyme blockers)
  • ARB's (Angiotensin Receptor Blockers)


The virulence or ability of the SARS class of viruses to cause death appears to be tied to the number of angiotensin receptors and this differs by person and by race or heritage.



There's an interesting chart here:

coronavirus and ace2 receptor levels by race


Why would this matter?


These receptors are mainly found in the heart and lungs (they are cardiovascular in nature after all).


The lungs are exposed to the virus (and any outside pathogen) of course and an unique ability of the SARS class of virus is that they can more easily attach to the angiotensin receptors.


This then leads to the viral pneumonia result that allows the virus to cross over from a cold to a deadly disease.


Basically, the virus has an easy way in (ACE2 receptors) and the immune system floods this area with cytokines as a response.


This fills up the lungs with the equivalent of snot or phlegm (basically our immune agents writ large) and we literally drown in our own immune response.


One of CBD's side effects is lower blood pressure but we don't have specific research on CBD and angiotensin receptors.


What we do find in research is how CBD calms the hyperactivation of the immune response in the lungs for other issues. 


We saw the effects on mice who were given a lung infection:

The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant.



That's a mouthful but basically, CBD calmed inflammatory immune response and improved lung function.


The leukocyte piece is important.


That's the white blood cell immune responder which signals a cascade of other responders to ramp up causing inflammation that makes the cells of the lungs "leaky".


ACE2 receptors may be acting as easy access for the SARS class of viruses to wreak havoc and set off a storm in our lungs.


Research shows that CBD has a calming effect on cytokine storms in general (see CBD and cytokine storm).  


Remember...it's generally not the virus that kills us but our immune system's scorched earth response.


Check out CBD and inflammation or CBD and neuroinflammation  (both with a bent for anxiety research) for deeper dives into these pathways. 


This is a good place to mention the real promise for a game-changer.




It's an anti-malarial and autoimmune drug (cheap, researched, and relatively safe) that is showing interesting effects.


The research is so promising, we did a full review on hydroxychloroquine and viral infection here.


We really think this may be part of turning the whole thing around and we've been "sky is falling" since January.  Find out why at the link above.


In the meantime, let's look at other tools we can use right now (assuming not sold out).

Other important antiviral supplements or herbs

Make sure to do your research but here some safety measures to look at: 



Elderberry is getting hard to find.  The ginger and quercetin should still be available.  Oregano is stronger for GI issues.  

Turmeric, zinc, and high dose C are also workarounds with actual research behind them for antiviral effects.


Let's look at each.

First, Elderberry and viral response

Elderberry (Sambucus or S. Nigra) was able to suppress viral replication in live bodies: 

However, treatment with S. nigra extracts reduced virus titers by four orders of magnitude at a multiplicity of infection (MOI) of 1 in a dose-responsive manner. 



This was important at an early point of infection so we're taking it preventatively during any hint of viral infection.


When they looked at viruses, they found their membrane was compromised from the elderberry.


Maybe, more importantly, another study found significant improvement in upper respiratory issues which is where a virus strikes the hardest (essentially viral pneumonia): 

Supplementation with elderberry was found to substantially reduce upper respiratory symptoms.  



CBD is also shown to calm the effects of infection in the lungs: 

The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. 



Remember... the immune system's overreaction in the lungs is the signature of severe cases for viral infections. 

Ginger and viral response 

In a study of Asian bird flu, ginger showed powerful anti-viral effects: 

Overall results revealed that the concentration of aqueous extract of ginger (10%), showing antiviral activity against H9N2, was less toxic to Vero cells (> 50% cell survival). 



Another study pinpointed the mechanism and effect in the immune system: 

Anti-influenza agents have been isolated from Z. officinale. TNF-α, reported as an anti-influenza cytokine, has been reported to be present in ginger. 



Another study on the cold virus (a type of coronavirus after all): 

Placebo group participants had a significantly longer duration of cold episode days (117 vs. 57, p = 0.02) and the average symptom score over these days was also significantly higher (583 vs. 247, p = 0.05).  


Oregano and viral response 

A study looked at oregano's effect on norovirus and the results were impressive: 

Our results demonstrate that carvacrol is effective in inactivating MNV within 1 h of exposure by acting directly on the viral capsid and subsequently the RNA. 



Another study focused on herpes and respiratory viruses with similar results: 

Thus, Mexican oregano oil and its main component, carvacrol, are able to inhibit different human and animal viruses in vitro.  



Just a head's up...if you have a stomach bug, oregano oil has a powerful effect there!

Quercetin and viral response 

We saved the best for last with exciting new research.


First, an introduction.


We take quercetin any way since it's such a powerful supporter of our natural detox system (glutathione - see CBD and glutathione).


Its antiviral effects are a very timely bonus: 

Here we found that quercetin inhibited influenza infection with a wide spectrum of strains. 



As for the mechanism: 

Mechanism studies identified that quercetin showed interaction with the HA2 subunit. Moreover, quercetin could inhibit the entry of the H5N1 virus using the pseudovirus-based drug screening system. 


This makes it important early in the process to avoid the infection altogether.


Hydroxychloroquine is about to become a household name (likely with lots of mispronunciation).


To a point where we're running short on it because doctors are writing scripts for themselves, their families and friends (per NPR).


Quercetin shares a key pathway with hydroxychloroquine (along with the EGCG - green tea extract which is not as safe) that may be the key behind its effect.


We did a full review on Supplements that share Hydroxychloroquine's PH effect here.


Quercetin is very safe and a no-brainer.  




We look forward to studies directly on CBD and various viruses.



Always work with a doctor or naturopath with any supplement!

The information provided here is not intended to treat an illness or substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider.




  • Thank you. Along those lines, check out this review on supplements that share a pathway with hydroxychloroquine here: https://indigonaturals.net/blogs/news/supplements-that-share-a-key-pathway-with-hydroxychloroquine-for-coronavirus

    And our follow up review of supplements with specific effects on pathways showing for viral infection: https://indigonaturals.net/blogs/news/potential-antivirals-with-nih-research-a-focus-on-safety-and-effectiveness

  • There isn’t nearly as much research on the other cannabinoids. Our favorite chart on the pathways they affect is here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5345356/table/T1/

    Personally, I don’t like that CBG blocks a key serotonin pathway. Again, it’s very early days in terms of research. Be safe and well!

  • You are my hero. I have been researching the coranavirus since December when my business partners in China told me there is something going on where people are becoming sick. My daughters are young COVID19 nurses frontline in Los Angeles and Newport Beach, CA. I have been formulating an immune booster tincture to help them stay healthy because I feel helpless on how to protect my baby girls while they help sick patients. I have been giving them immune boosters for early stages to stop the virus replication and CBD for all stages with the most important with inflammation and cytokine suppression during the storm. This has helped them a lot. I have also given the supplements to a sick friend who showed signs of being infected with the virus….next day he thanked me so much because it was night and day on how he felt after taking the supplements. Now I thank you so much because now I don’t feel alone. These same articles I would be so geeked out on the information but no one really believed me. This is awesome. Please contact me.


    Al Guzman
  • Mersa, Sars and Covoid-19 are all forms of the Coronavirus

  • This is an outstanding primer. I’m growing CBG in Paonia and wonder if it is as therapeutic as CBD?

    Robert Hill

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