Nicotine: The Research
Nicotine is the alkaloid of the tobacco plant, and in tiny amounts of tomatoes, potatoes, peppers and aubergines. It acts on the nicotinic acetylcholine receptors found throughout the brain, muscles, gut and immune system, which is why it is studied for far more than addiction: memory and Parkinson’s disease, bowel inflammation, mood, weight, pain and cancer biology, as well as for its toxicity. This section collects that research from PubMed, one page per topic, each paper summarised in plain language and linked to its PubMed record.
Nicotine is not the same thing as smoking. Most of the harm of cigarettes comes from burnt tobacco — tar, carbon monoxide and nitrosamines — and the papers here are about nicotine itself, its metabolites and its receptors. The collection is research only and is separate from the claims documented on the Dr. Bryan Ardis pages. It is not medical advice.
Table of Contents
Research at a Glance
How many papers each page lists, and how much of the collection is research in people rather than in cells or animals. Hover over a bar for its count.
By Topic
581 papers in the collection so far, updated weekly. A paper that fits more than one page is listed on each.
Brain and Memory
Attention, memory, mild cognitive impairment, Alzheimer's and Parkinson's disease: what the trials and the laboratory work on nicotine and the thinking brain report. 27 papers.
Read the research →Addiction and Withdrawal
How nicotine dependence forms in the reward system, what withdrawal does, and the research on quitting. 40 papers.
Read the research →Patches, Gum and Delivery
Patches, gum, lozenges, sprays, pouches and vapour: how each form delivers nicotine to the blood, and what the pharmacokinetic studies measure. 44 papers.
Read the research →Heart and Blood Vessels
Heart rate, blood pressure, arrhythmia and the lining of the arteries: what nicotine on its own, apart from smoke, does to the cardiovascular system. 31 papers.
Read the research →Toxicity and Safety
Overdose, child and pet poisoning, pregnancy, adolescent exposure and the lethal-dose question: the safety research on nicotine. 25 papers.
Read the research →Cancer Research
Nicotine is not the carcinogen in tobacco smoke, but it does act on tumour cells. Cell, animal and human studies on nicotine, its metabolites and cancer. 25 papers.
Read the research →Mood and Mental Health
Depression, anxiety, schizophrenia and ADHD: the research on why nicotine use runs so high in these conditions and what nicotine itself does to mood. 46 papers.
Read the research →Metabolism and Weight
Appetite, weight, insulin and blood sugar: the research behind the weight gain that follows quitting and what nicotine does to glucose control. 19 papers.
Read the research →Inflammation and Immunity
The cholinergic anti-inflammatory pathway, the alpha-7 receptor on immune cells, ulcerative colitis and sepsis: the research on nicotine as an immune signal. 13 papers.
Read the research →Metabolites and Chemistry
Cotinine, 6-hydroxy-nicotine, CYP2A6 and how the body breaks nicotine down: the research on nicotine's chemistry and its metabolites. 29 papers.
Read the research →By Condition
The conditions most often discussed with nicotine, each with its own research page.
Alzheimer's Disease
Nicotinic receptor loss, amyloid, and the patch trials in mild cognitive impairment: the published research on nicotine and Alzheimer's disease. 30 papers.
Read the research →Parkinson's Disease
Why smokers get Parkinson's less often, the dopamine-neuron studies, and the nicotine patch trials: the published research on nicotine and Parkinson's. 27 papers.
Read the research →COVID-19
The smoker paradox in early COVID-19 data, the nicotinic-receptor hypothesis, and the trials that tested nicotine patches against the virus. 33 papers.
Read the research →Arthritis and Pain
Rheumatoid arthritis, osteoarthritis, joint inflammation and nicotine's effect on pain: the published research. 38 papers.
Read the research →Ulcerative Colitis
Ulcerative colitis is the bowel disease that is rarer in smokers; the nicotine patch, enema and capsule trials and the gut-immune studies. 41 papers.
Read the research →Schizophrenia
Very high smoking rates in schizophrenia, the alpha-7 receptor gene, sensory gating and cognition: the published research on nicotine and schizophrenia. 32 papers.
Read the research →Type 1 Diabetes
Autoimmune diabetes, the pancreatic islets and the alpha-7 receptor: the published research on nicotine and type 1 diabetes. 16 papers.
Read the research →Autism
Nicotinic receptors in autism, prenatal nicotine exposure, and the small studies of nicotine on autism symptoms. 30 papers.
Read the research →Multiple Sclerosis
Snus, smoking and MS risk, and the animal studies of nicotine on brain inflammation and demyelination. 29 papers.
Read the research →Thyroid and Hashimoto's
Autoimmune thyroiditis is less common in smokers; the research on nicotine, thyroid hormone and thyroid autoimmunity. 17 papers.
Read the research →Heart Rhythm and Myocarditis
Arrhythmia, heart-muscle inflammation and nicotine's action on the heart's own receptors: the published research. 26 papers.
Read the research →Glioblastoma
Nicotinic receptors on glioma cells and the laboratory studies of nicotine, its metabolites and brain-tumour growth and treatment response. 21 papers.
Read the research →Newest in the Collection
- Testing the effects of nicotine concentration and nicotine source claims on oral nicotine pouch packaging engagement, self-reported perceptions and use intentions, and product trial in young adults and adults: Protocol for a randomized trial (2026, human trial) — Patches, Gum and Delivery
- Mutually exclusive patterns of cigarette and e-cigarette use and self-rated anxiety among adolescents: a national school-based cross-sectional analysis (2026, human observational study) — Mood and Mental Health
- A Randomized Factorial Trial of Varenicline, Nicotine Lozenges, and Smartphone Medication Adherence Reminders for Smoking Cessation: Protocol for the COMBO II Study (2026, human trial) — Addiction and Withdrawal
- Dermal Uptake of Thirdhand Cigarette Smoke from Clothing (2026, human trial) — Metabolites and Chemistry
- The Age to Vape: Nicotine Use and Behavior Associations in Young Adults (2026, human observational study) — Mood and Mental Health
- AB-free Kava reduces anxiety-like behavior without preventing nicotine-induced exploration suppression in mice (2026, animal study) — Mood and Mental Health
- Nontobacco Nicotine in Orthopaedic Surgery: Current Knowledge and Limitations of Database Investigations (2026, review) — Patches, Gum and Delivery
- Imaging [18F]FDG PET/CT pilot study of nicotinic acetylcholinergic receptor ฮฑ2 knock-out mice and ฮฑ2 hypersensitive mice compared to control mice: Male-female differences and nicotine effects (2026, animal study) — Brain and Memory
- Examining the Impact of Neurodevelopmental Nicotine Exposure on Cortical Excitation/Inhibition Homeostasis Markers in a Cerebral Organoid Model of Schizophrenia (2026, cell study) — Toxicity and Safety
- Silymarin Attenuates Nicotine-Associated Testicular Degeneration and Systemic Oxidative and Inflammatory Changes in Mice (2026, animal study) — Toxicity and Safety
- Electronic Properties of Common Psychostimulants in Aqueous Environments (2026, chemistry / laboratory method) — Metabolites and Chemistry
- Effects of Endocannabinoid System Modulation on Cholinergic-Induced Anxiety-like Behaviors in Mice (2026, animal study) — Mood and Mental Health
How This Collection Is Built
- Each page runs its own PubMed search for papers in which nicotine is a major subject and that have an abstract. The search is linked at the bottom of every page.
- Each paper’s record — title, authors, journal, year, PMID and DOI — is taken from PubMed itself, never typed by hand, and retracted papers are skipped.
- The plain-language summary is written from the paper’s own abstract, keeping its numbers and saying whether the work was in cells, animals or people. Papers that only use nicotine as a marker of smoking are left out.
- New papers are added every week, and the newest appear at the top of each page.
Connections
- The Neuromuscular Junction: How a Nerve Commands a Muscle โ interactive animation
- Medicines and Oils
- The Nicotine Patch, animated — how a patch, gum and a cigarette differ in the blood
- Dr. Bryan Ardis — his nicotine claims, documented on their own pages
- Nicotinic Acetylcholine Receptors
- Secondhand Smoke — what burnt tobacco adds that nicotine alone does not
- Vitamin B3 (Niacin) — named after nicotinic acid, an oxidation product of nicotine, but a different molecule