Nicotine and Viruses
The relationship between nicotine and viruses reaches far beyond nicotine’s familiar association with smoking.
The human body naturally contains nicotinic acetylcholine receptors—specialized communication gateways found throughout the brain, nervous system, immune system, muscles, blood vessels and cellular structures. These receptors respond naturally to acetylcholine, one of the body’s essential signaling molecules. They can also be activated by nicotine.
Emerging research proposes that certain viruses or viral proteins may interact with nicotinic acetylcholine receptors and interfere with normal cholinergic communication. This has led researchers, physicians and independent health educators—including Dr. Bryan Ardis—to explore an important possibility:
Could carefully delivered, non-inhaled nicotine help restore receptor activity and relieve symptoms associated with viral or postviral illness?
The strongest human evidence currently relates to low-dose nicotine patches and Long COVID. Published case reports, outcomes reported by 231 patch users and objective PET brain imaging have created a meaningful human signal that deserves attention.
Human Nicotinic Acetylcholine Receptors
The receptors involved in this research are properly called nicotinic acetylcholine receptors, commonly abbreviated as nAChRs.
They are sometimes casually called “nicotine receptors,” but nicotine did not create them. They are natural components of the human body, and acetylcholine is their primary biological messenger. They received the name “nicotinic” because nicotine can also bind to and activate them.
Different nicotinic receptor subtypes—including α4β2, α7 and others—participate in:
Attention, learning and memory
Neurotransmitter release
Autonomic nervous-system regulation
Muscle activation
Cellular energy regulation
Immune-cell communication
Blood-vessel function
Inflammatory signaling
The cholinergic anti-inflammatory pathway
These receptors are present in neurons, immune cells, epithelial cells and other tissues. Some nicotinic receptor subtypes have also been identified on mitochondrial membranes, creating a possible connection among cholinergic signaling, cellular energy, oxidative stress and cell-survival processes.
Because these receptors operate across so many systems, disruption of their normal activity could contribute to a wide range of neurological, immune, vascular, muscular and autonomic symptoms.
Acetylcholine and Whole-Body Communication
Acetylcholine is one of the body’s most important chemical messengers. It helps nerves communicate, muscles contract, the brain process information and the autonomic nervous system regulate internal functions.
Nicotinic acetylcholine receptors act as gated channels. When properly activated, they allow charged particles to move across cellular membranes and help coordinate communication within and between cells.
This signaling influences:
Cognitive processing
Alertness and attention
Speech and movement
Heart-rate regulation
Blood-vessel tone
Digestion
Immune activity
Inflammatory balance
Mitochondrial function
The body’s response to physical exertion
When cholinergic communication is impaired, symptoms may appear in several systems simultaneously. This is one reason nicotinic receptors have become an important area of investigation in complex postviral conditions.
Do Viruses Interact With Nicotinic Receptors?
Evidence indicates that some viruses or viral proteins can bind to or influence nicotinic acetylcholine receptors.
Rabies provides one of the clearest historical examples. Rabies-virus glycoprotein can bind to nicotinic receptors at the neuromuscular junction, helping the virus enter peripheral nerves.
Researchers have also identified structural similarities among portions of certain viral proteins, nicotinic-receptor-binding toxins and other molecules capable of influencing cholinergic signaling.
Nicotinic-receptor interactions have been explored in connection with:
Rabies
HIV
SARS-CoV-2
Influenza-related pathways
Several animal and insect viruses
Each virus interacts with the body in its own way, but the growing receptor research reveals an important pattern: nicotinic acetylcholine receptors may be involved in how multiple viruses influence neurological, immune and autonomic function.
SARS-CoV-2 Spike Protein and Nicotinic Receptors
A segment of the SARS-CoV-2 spike glycoprotein contains an amino-acid sequence with similarities to proteins found in certain cholinergic toxins.
Laboratory research has reported that spike-derived material can interact with α7 nicotinic acetylcholine receptors and influence their function. Researchers have observed both potentiating and inhibitory effects depending on factors such as concentration, receptor subtype and receptor configuration.
Other studies have investigated α4β2 and additional nicotinic receptor subtypes.
These receptors contain multiple binding regions and can shift among open, closed, sensitized and desensitized states. The biological relationship may therefore involve receptor occupancy, receptor shape, receptor sensitivity and the availability of different binding sites.
The developing hypothesis is that persistent viral proteins may interfere with normal receptor signaling, contributing to neurological, immune, inflammatory, mitochondrial, vascular or autonomic symptoms.
SARS-CoV-2 Spike Ectodomain Targets α7 Nicotinic Acetylcholine Receptors
Functional Interaction Between SARS-CoV-2 Spike and α7 Nicotinic Receptors
Cholinergic Disruption and Long COVID
Long COVID can involve symptoms that appear disconnected but may share underlying neurological, immune, vascular or cellular pathways.
Reported symptoms include:
Brain fog
Memory difficulties
Poor concentration
Post-exertional malaise
Persistent fatigue
Altered smell or taste
Dizziness
Rapid heart rate
POTS-like symptoms
Temperature-regulation problems
Muscle weakness
Sleep disturbance
Headaches
Speech or language difficulties
Digestive changes
Inflammatory symptoms
Altered immune responses
Nicotinic acetylcholine receptors participate in many of the systems affected by these symptoms. Researchers have therefore proposed that impaired cholinergic neurotransmission may be one important part of the Long COVID picture.
This receptor-centered explanation can connect with other findings involving viral persistence, immune dysregulation, autoantibodies, neuroinflammation, microvascular changes, mast-cell activation and mitochondrial dysfunction.
Cholinergic disruption may help explain how several of these processes become connected.
Why Nicotine Patches Are Being Investigated
Nicotine has a strong affinity for nicotinic acetylcholine receptors. When delivered through a patch, it enters the circulation gradually and steadily rather than producing the rapid arterial increase associated with inhalation.
Researchers have proposed several ways low-dose transdermal nicotine might support recovery:
Activating receptors whose signaling has become impaired
Producing beneficial receptor conformational changes
Increasing the availability of receptor-binding sites
Supporting acetylcholine-orchestrated neurological communication
Influencing the cholinergic anti-inflammatory pathway
Supporting autonomic and immune signaling
Potentially displacing persistent viral material from affected receptors
The proposed displacement mechanism gained important support when symptom recovery was accompanied by increased receptor availability on PET imaging.
Four Long COVID Cases Reported in 2023
A 2023 peer-reviewed case series described four people with persistent post-COVID symptoms who used low-dose transdermal nicotine.
Symptoms included:
Fatigue
Cognitive impairment
Poor concentration
Sleep disturbance
Loss of smell or taste
Muscle weakness
Other persistent neurological or physical symptoms
The paper documented substantial improvement across the cases, with complete symptom remission reported in multiple participants.
One participant mistakenly received a higher initial dose and discontinued the patch within hours, yet the paper still reported eventual symptom remission. This experience also demonstrated that individual sensitivity can vary and that more nicotine is not necessarily more effective.
All four participants experienced substantial improvement. The consistency and speed of these changes opened an important new direction in Long COVID research.
Read the 2023 Long COVID case series
2025 PET Imaging Provided Objective Evidence
A 2025 paper published in Bioelectronic Medicine presented an especially important Long COVID case involving a 44-year-old teacher who had experienced disabling symptoms for approximately three and a half years.
Her symptoms included:
Severe speech-fluency impairment
Brain fog and cognitive overstimulation
Fatigue
Post-exertional malaise
Dizziness
Cold extremities
Numb fingers
Burning or irritated eyes
Other neurological and functional difficulties
The patient received continuous low-dose transdermal nicotine at 7 mg per 24 hours for seven consecutive days.
Researchers used a specialized PET tracer called (-)-[18F]Flubatine to examine the availability of α4β2 nicotinic acetylcholine receptors before and after treatment.
The follow-up PET scan was performed after nicotine had been discontinued and a cotinine test confirmed that nicotine’s principal metabolite was no longer present. This helped researchers distinguish a sustained change in receptor availability from the immediate presence of nicotine occupying the receptors.
Following the treatment period, the researchers reported:
A 7.6% increase in brain tracer distribution volume
Increased availability of α4β2 receptor-binding sites
Major neurological improvement
Full restoration of speech formation
Improved overall functioning
A return to teaching without the previous impairment
Changes in receptor availability were also observed in several areas outside the brain, including muscles, liver and vertebral tissue. This is especially interesting because nicotinic acetylcholine receptors are distributed throughout the body rather than being confined to the nervous system.
This deeply documented human case connected clinical recovery with measurable biological changes, making it one of the most compelling findings in the emerging research.
Read the complete 2025 open-access paper
Outcomes Reported by 231 Patch Users
The same 2025 publication included a descriptive analysis of 231 people who had used low-dose transdermal nicotine while experiencing Long COVID, ME/CFS or related postviral symptoms.
The results were notable:
73.5% reported significant symptom improvement.
Approximately one-third reported remission.
Improvements were reported across fatigue, cognition, post-exertional symptoms and overall functioning.
Side effects were generally described as minor.
The authors characterized low-dose transdermal nicotine as promising, affordable and worthy of continued clinical investigation.
This was a patient-outcomes survey rather than a placebo-controlled trial, but its size considerably expanded the human evidence beyond the original case reports.
The experiences of 231 people are meaningful. Patient-reported outcomes are often how promising therapeutic directions first become visible.
The survey demonstrates that the original case-series participants were not the only people reporting substantial improvement. Some individuals living with difficult, persistent illness reported regaining meaningful parts of their lives—and approximately one-third described their improvement as remission.
Dr. Bryan Ardis and the Nicotine Conversation
Dr. Bryan Ardis, a retired chiropractor, author and health educator, has played a prominent role in bringing the possible relationship among viruses, nicotinic receptors and nicotine to a wider public audience.
He has drawn attention to:
Nicotinic acetylcholine receptors throughout the human body
Research connecting certain viral proteins with nicotinic receptors
The 2023 Long COVID case series
Human experiences involving nicotine patches and gum
The difference between pharmaceutical nicotine and cigarette smoke
The possibility that nicotine has overlooked therapeutic applications
Dr. Ardis did not conduct the 2023 case series or the 2025 PET-imaging research. His contribution has been interpreting, connecting and publicly amplifying this body of work.
His advocacy has encouraged many people to reconsider nicotine as a molecule rather than viewing it only through the history of cigarettes. He has also encouraged greater public interest in nicotinic acetylcholine receptors and the ways viral proteins may interfere with them.
His work belongs in this conversation because he helped bring a relatively overlooked scientific possibility into public view.
Dr. Ardis’s Reported Family Experience With Nicotine Gum
In a detailed interview, Dr. Ardis described his wife’s experience with persistent symptoms following COVID-19.
According to his account, she experienced symptoms for approximately two years, including:
Loss of taste and smell
Ringing in the ears
Dizziness
POTS-like difficulty when standing
Problems that had not resolved through other approaches they tried
Dr. Ardis reported that these symptoms resolved within three days after she began using nicotine gum.
He also openly described his own different response to gum. He reported experiencing nausea, dizziness and digestive discomfort even with a lower-dose product.
These contrasting experiences illustrate an important part of the nicotine conversation: people can respond differently to the same form of nicotine.
His wife’s recovery is part of the human story that led Dr. Ardis to continue advocating for greater attention to nicotine and nicotinic-receptor research.
Read the Dr. Bryan Ardis interview transcript
Nicotine Gum and Postviral Symptoms
Nicotine gum delivers nicotine without smoke, tar or combustion. Unlike a patch, gum produces shorter periods of nicotine exposure followed by declining levels.
Published Long COVID research has focused principally on patches, while the developing gum evidence comes from individual experiences, including the recovery described by Dr. Ardis’s wife.
These experiences help identify patterns that future research can explore.
The current evidence includes:
Published human evidence involving patches
Patient and family experiences involving gum
A developing biological explanation involving nicotinic receptors
Meaningful opportunities for gum-specific human research
Why Continuous Patch Delivery May Matter
The difference between a patch and gum may involve more than convenience.
A patch supplies nicotine slowly and continuously, while gum produces shorter periods of exposure. The authors of the 2025 paper proposed that continuous transdermal delivery may be particularly relevant to their receptor-displacement hypothesis.
If persistent viral material is attached to affected receptors, short periods of nicotine exposure might allow that material to reattach after nicotine levels decline. Sustained transdermal delivery could provide more continuous receptor engagement while displaced material is processed by the immune system.
This proposed explanation helps clarify why published Long COVID research has focused more heavily on patches than gum.
It also demonstrates why the form, timing and delivery pattern of a substance can matter as much as the substance itself.
Can Nicotine Protect Receptors From Viruses?
The receptor hypothesis raises two related possibilities:
Nicotine may occupy or activate nicotinic receptors in ways that influence viral-receptor interactions.
Nicotine may help restore signaling after viral or spike-related material has disrupted receptor function.
The strongest human evidence currently involves symptom improvement and receptor restoration in people experiencing Long COVID or related postviral illness.
A large French clinical trial was registered to investigate whether nicotine patches could reduce SARS-CoV-2 infections among healthcare workers. The registered trial reflects serious scientific interest in whether continuous nicotine-receptor engagement could influence susceptibility to infection.
View the NICOVID-PREV trial registration
A precise way to express the developing evidence is:
Certain viruses or viral proteins may interact with nicotinic acetylcholine receptors. Nicotine may influence receptor availability, activation and signaling, and emerging human evidence suggests that low-dose transdermal nicotine may help people experiencing Long COVID or related postviral illness.
Why Nicotine Patches and Smoking Are Different
The emerging research concerns pharmaceutical nicotine—not cigarette smoking.
Smoking exposes the body to:
Combustion products
Carbon monoxide
Tar
Fine particles
Tobacco-specific nitrosamines
Polycyclic hydrocarbons
Numerous toxic chemicals
Smoking also delivers nicotine to the brain within seconds, producing a rapid reward response that differs substantially from the slow, steady delivery of a transdermal patch.
A review discussed in the 2025 paper evaluated 33 studies involving transdermal nicotine in nonsmokers or former smokers. The review reported that the studies did not observe withdrawal symptoms or addictive behavior following patch use.
Longer follow-up in nonsmokers also found no craving for inhaled nicotine or movement toward another nicotine source after transdermal treatment ended.
Route, speed, amount and context of delivery matter.
Nicotine should be studied as its own biologically active molecule rather than treated as though it is identical to smoking.
Cholinergic Anti-Inflammatory Pathway
The vagus nerve and nicotinic acetylcholine receptors participate in a regulatory system known as the cholinergic anti-inflammatory pathway.
Activation of α7 nicotinic receptors on immune cells may influence the release of inflammatory messengers such as tumor necrosis factor, interleukin-6 and other cytokines.
This pathway gives researchers another possible explanation for reported improvements involving:
Inflammation
Brain fog
Immune overactivation
Mast-cell-related symptoms
Autonomic imbalance
Post-exertional symptoms
Persistent fatigue
Nicotine’s possible effects in postviral illness may therefore involve both receptor restoration and wider changes in neurological and immune communication.
Explore the related page: Nicotine, Inflammation and Immune Signaling
Mitochondria, Energy and Postviral Fatigue
Several nicotinic receptor subtypes have been identified on mitochondrial membranes.
Mitochondria produce most of the usable energy required by cells. They also participate in calcium regulation, oxidative-stress control and cell-survival signaling.
If nicotinic-receptor disruption affects mitochondrial communication, it could contribute to:
Reduced cellular energy
Persistent fatigue
Post-exertional malaise
Muscle weakness
Poor exercise tolerance
Increased oxidative stress
Slow recovery after exertion
This offers another possible connection between cholinergic dysfunction and the deep physical exhaustion reported in Long COVID and ME/CFS.
A Hopeful Interpretation of the Evidence
The nicotine-receptor hypothesis has progressed through several meaningful stages:
Established knowledge of human nicotinic acetylcholine receptors
Biological plausibility based on cholinergic physiology
Structural and laboratory evidence involving viral proteins
A four-person Long COVID case series
Repeated patient-reported experiences
A 231-person survey
Significant improvement reported by 73.5% of respondents
Remission reported by approximately one-third
Objective PET imaging showing increased receptor availability
Restoration of speech and return to work in a deeply impaired patient
This is no longer an idea supported only by molecular theory.
Continued studies can help identify which people are most likely to respond, which symptoms may improve, what delivery patterns are most effective and how lasting the improvements may be.
Hope does not require dismissing what has already happened while waiting for every future study.
People who had been ill for months or years reported meaningful improvement. Some reported remission. One patient experienced profound recovery accompanied by measurable changes in nicotinic receptor availability.
Those outcomes deserve to be seen, studied and honored.
How to Explore Nicotine Wisely
Nicotine is biologically active, and individual responses can differ. Some people tolerate patches or gum well, while others may experience nausea, dizziness, sleep changes, skin irritation or digestive discomfort.
The research discussed on this page involves low-dose pharmaceutical nicotine rather than smoking, vaping or high-dose exposure.
Anyone exploring nicotine for a health purpose should consider the form, amount, existing nicotine exposure, personal health history and individual response.
Explore the companion page: Nicotine Gum and Patches
Questions and Answers
Does the human body naturally have nicotine receptors?
The body naturally contains nicotinic acetylcholine receptors. Acetylcholine is their primary natural messenger. They are called nicotinic receptors because nicotine can also bind to and activate them.
Do viruses attack nicotinic acetylcholine receptors?
Some viruses or viral proteins can bind to or influence nicotinic acetylcholine receptors. Rabies provides a recognized example, and laboratory research supports interactions involving SARS-CoV-2 spike material. Nicotinic receptors may be one pathway through which viruses affect neurological, muscular, immune and autonomic function.
Can a nicotine patch help protect against viral infection?
Nicotine’s ability to occupy and activate nicotinic receptors has led researchers to investigate its preventive potential. A French nicotine-patch prevention trial was registered, while the strongest published human results currently involve Long COVID recovery.
Have nicotine patches helped people with Long COVID?
Yes. Published case reports describe substantial improvement and remission. A 2025 survey found that 73.5% of 231 users reported significant improvement, with approximately one-third reporting remission.
Is there objective evidence beyond personal reports?
Yes. A 2025 clinical case used PET imaging before and after low-dose transdermal nicotine. Researchers reported increased availability of α4β2 nicotinic receptor-binding sites alongside significant neurological and functional recovery.
What happened to the patient in the PET-imaging case?
The patient had been impaired for approximately three and a half years. Following low-dose transdermal nicotine, her speech was fully restored, her neurological condition improved and she returned to teaching without the previous impairment.
Does nicotine remove spike protein from receptors?
Competitive displacement is one proposed mechanism. The 2025 PET study found increased receptor availability after treatment alongside substantial neurological recovery, providing measurable support for the receptor-restoration hypothesis.
Why might patches work differently from gum?
Patches provide slow, continuous nicotine delivery. Gum produces shorter periods of exposure. Researchers have proposed that continuous receptor engagement may be particularly relevant to the receptor-displacement process.
Has nicotine gum helped people with Long COVID?
Dr. Bryan Ardis and other individuals have reported meaningful improvement associated with nicotine gum. Dr. Ardis stated that his wife’s persistent symptoms—including loss of taste and smell, tinnitus, dizziness and POTS-like symptoms—resolved within three days.
Did Dr. Bryan Ardis conduct the Long COVID studies?
Dr. Ardis helped bring attention to and interpret the research. The published case series, survey and PET-imaging work were conducted by other researchers.
Is nicotine the same as smoking?
No. Nicotine is one biologically active molecule. Cigarette smoke contains combustion products, carbon monoxide, tar, particles and numerous toxic chemicals. Pharmaceutical patches and gum deliver nicotine without combustion.
Are nicotine patches addictive in people who have never smoked?
A review of 33 transdermal nicotine studies involving nonsmokers or former smokers reported no withdrawal symptoms or addictive behavior. Slow transdermal delivery affects the brain differently from rapidly inhaled nicotine.
What is the most important takeaway?
Nicotinic acetylcholine receptors may provide an important biological connection among viral illness, neurological symptoms, autonomic dysfunction, inflammation and postviral fatigue. Human findings involving low-dose nicotine patches are hopeful, measurable and deserving of continued attention.
Closing Perspective
The human body contains an extraordinary communication network built around acetylcholine and its receptors. As researchers continue examining how viruses may interfere with that network, nicotine has emerged as an unexpected molecule of interest.
Its story is being separated from the story of smoking.
The 2023 case reports opened an important door. The 2025 PET findings added objective biological evidence. The experiences reported by 231 patch users showed that meaningful improvement was not confined to one patient or one small case series.
Dr. Bryan Ardis helped bring these ideas and experiences into public conversation. Researchers are exploring the mechanisms. Patients are contributing observations that may help shape the next generation of studies.
The research has already given people something deeply valuable: a new direction, a biological explanation worthy of investigation and evidence that recovery may remain possible even after years of illness.
Continue Exploring
Nicotine Gum and Patches
Nicotine, Inflammation and Immune Signaling
Nicotine and the Brain
Nicotine and the Human Body
Tobacco, Nicotine and Human Health
Ivermectin and Long COVID, Inflammation, Viral Persistence, Immunity and Emerging Research
Scientific sources:
2025 Long COVID paper with PET imaging and 231-person survey
2023 four-person Long COVID case series