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Nicotine is the main stimulatory compound found in cigarettes and is now sold in vaporizers and patches in isolation. It works on the acetylcholine system, and is implicated in cognitive enhancement.

Our evidence-based analysis on nicotine features 256 unique references to scientific papers.

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Summary of Nicotine

Primary information, health benefits, side effects, usage, and other important details

Nicotine is one of the many, albeit most famous, alkaloid in cigarettes that naturally occurs in tobacco. Nicotine itself exists in many other plants (those of the Solanaceae family such as eggplant or peppers) but at miniscule doses. When nicotine is isolated from tobacco containing products or cigarettes, it has a significantly different profile of effects in the body and for all intents and purposes should be seen as a different intervention.

Nicotine has a few mechanisms at its roots. The first is that nicotine mimics the neurotransmitter acetylcholine and can directly activate acetylcholine receptors (which can then induce increases of catecholamines such as adrenaline a dopamine; this mechanism underlies both potential addiction and fat burning). Nicotine may also act as an anti-estrogenic compound, inhibiting aromatase and one of the two estrogen receptors directly; this may underlie some of the side-effects associated with chronic usage of nicotine, particularly in women. Finally, nicotine is pro-oxidative in nature but at a level which may be hormetic in nature, that works with the acetylcholine mechanism just mentioned to exert anti-inflammatory effects.

Nicotine appears to have a role as a fat burner due to its mechanisms, which for the most part increase adrenaline and then work through beta-adrenergic receptors (the molecular target of ephedrine); this increase in adrenaline mediates the increase in metabolic rate which is significant but short-lived with moderate usage. The increase in lipolysis (how available fatty acids are to be burnt) appears to be mediated by other, possibly pro-oxidative, mechanisms and not by adrenaline.

This increase in catecholamines also underlies many benefits of nicotine on cognition (attention and focus mainly) while the acetylcholine mimicking may promote a nootropic effect inherently.

In regards to addiction, the risk of nicotine and addiction is a measurement between how much nicotine is taken (with more nicotine being associated with greater risk) and the speed of nicotine reaching the brain (with faster spikes in neural concentration being associated with both greater perceived benefits and greater risk of addiction). Addiction is not inherent to nicotine, as is evidenced by nicotine therapy being used to curb cigarette addictions. Gums and patches have less potential risk for addiction than do cigarettes (with inhalers in the middle) due to speed nicotine reaches the brain.

Acutely, potential side-effects of nicotine are similar to acute side-effects of other stimulants such as ephedrine, yohimbine, or caffeine due to increasing catecholamines. Over the long term, the side-effect profile of nicotine may rival ephedrine as those two retain a degree of catecholamine secretion over time (the other two losing efficacy in 2 weeks or less).

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How to Take

Recommended dosage, active amounts, other details

Nicotine can be administered via several methods (excluding cigarettes, which are not recommended due to risks greatly exceeding benefits):

  • An inhaler, which lets you rapidly feel the effects of nicotine (and inherently carries more risk than other forms due to the speed at which it works)

  • Topical patches, which have about a 1 hour delay between application and absorption and maintain constant serum levels of nicotine but with less cognitive spike (least risk potential, least nootropic potential)

  • Chewing gums, which are sort of an intermediate between the two

There is currently insufficient evidence to suggest an 'optimal dose' of nicotine for non-smoking individuals.

For non-smoking individuals, it would be prudent to follow stimulant usage guidelines and start with a low dose and work up. This includes buying 2mg gums or cutting a 24mg nicotine patch into quarters to start, then work up to what is seen as the minimum effective dose. There is currently no established 'threshold' for when risk becomes too great as it varies between individuals.

If using nicotine as Nicotine Replacment Therapy (to curb smoking cravings), then following the instructions on the product is sufficient. These instructions may be excessive for a non-smoking individual.

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Human Effect Matrix

Unlocked for Examine members

The Human Effect Matrix summarizes human studies to tell you what effects Nicotine has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-b - Moderate See all 4 studies
Mixed effects on blood pressure
grade-b - High See all 3 studies
Long term insulin sensitivity does not appear to be highly affected, but acutely nicotine exposure can reduce insulin sensitivity
- See 2 studies
Reduced anxiety symptoms have been noted in persons with cognitive decline, where anxiety was relieved as a symptoms of cognitive decline. In otherwise healthy persons prone to anxiety attacks, nicotine may be able to cause them.
grade-c Minor - See study
An improvement in cognition has been noted in persons with mild cognitive impairment
grade-c Minor - See study
An acute suppression of growth hormone has been noted with nicotine to a small degree
grade-c Minor Very High See 2 studies
An increase in heart rate is present after nicotine ingestion due to the stimulatory properties
grade-c Minor - See study
An increase in luteinizing hormone has been noted
grade-c Minor - See study
An increase in memory has been noted with ingestion of nicotine in persons with mild cognitive impairment
grade-c Minor - See study
Chewing gum containing nicotine can increase the metabolic rate in a dose-dependent manner (3.7-4.9% with 1-2mg nicotine) when measured for the 180 minutes following 20 minutes of chewing.
grade-c Minor - See study
A decrease in penile girth in the flaccid state is noted, which is thought to be secondary to reduced blood flow
grade-c Minor - See study
An increase in prolactin has been noted with nicotine ingestion
grade-c Minor - See study
A decrease in reaction time is noted with acute nicotine ingestion
grade-c Minor Moderate See 2 studies
Possible minor weight reducing effects occur in interventions using nicotine, but they are highly unreliable and likely mediated by lesser food intake rather than inherent fat burning effects
grade-c - - See study
No significant influence on fasting glucose levels
grade-c - - See study
No significant influence on cortisol levels
grade-c - - See study
No significant influence on depressive symptoms
grade-c - - See study
When nicotine increases metabolic rate, there is no change in rates of fat or glucose oxidation.
grade-c - - See study
No significant influence on fasting insulin levels
grade-c - Very High See 2 studies
There do not appear to be any significant interactions with nicotine and libido
grade-c - - See study
No significant influence on self control and inhibitions
grade-c - - See study
No significant influence on testosterone levels
grade-d - - See study
No significant influence on attention in otherwise healthy persons

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Things to Note

Is a Form Of

Other Functions:

Do Not Confuse With

Nicotinic acid (a name for niacin or Vitamin B3), Cigarettes (The vessel containing nicotine)

Caution Notice

Excessive usage of nicotine still confers addictive properties even if not in cigarette form

  • Nicotine inherently has risk for addiction, which is a dependent on how much nicotine is ingested and how fast it reaches the brain

  • Patches have the least risk of addiction and least cognitive enhancing properties, followed by chewing gums and then with inhalers having most potential addiction risk of nicotine replacement therapy; all of which are less of a risk than cigarettes

  • Women appear to have a greater risk of addiction than men

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