Nicotine & Testosterone: Is Smoking Tobacco Bad for Men?

People often like to say that it is common sense that tobacco is bad for you. In this article we will find out the truth and how nicotine and smoking affect testosterone levels in men.

If I rolled up a fat cigarette filled with ground coffee beans, it is likely you would consider this a more healthy option than the ordinary cigarette. But is it? Why is there so much stigma attached to the topic of tobacco?

After all, is it the tobacco leaf in itself that is killing people?

The reality is that smoking those coffee beans is likely no more damaging to you than smoking the tobacco leaf, as long as it is additive free tobacco that is.

Clearly, common sense should also dictate that smoking and inhaling this smoke is bad for you, since the combustion of different materials releases carcinogenic chemicals that wreck havoc on the human physiology.

The fact is that it doesn’t matter if you’re smoking natural tobacco, ground coffee beans, eating smoked meats or even inhaling the secondary smoke when BBQing, the process and health implications are similar.

Here’s from a study on smoked foods:

• "Smoking is a well-known source of food contamination caused by carcinogenic polycyclic aromatic hydrocarbons. Epidemiological studies indicate a statistical correlation between the increased occurrence of cancer of the intestinal tract and the frequent intake of smoked foods."

These "carcinogenic polycyclic aromatic hydrocarbons” are the same in any process of smoking and hence have nothing to do with the tobacco leaf in itself.

What makes matters worse, however, is that in conventional mass-produced cigarettes, a lot of additives are added to make them more addictive, produce a stronger effect and taste better.

A lot of these artificial additives have no research backing up if they are safe for combustion. This is because tobacco smoking is already considered an unhealthy habit which further justifies big tobacco corporations not having to try to make it any healthier for your sake.

Basically, they do not have to care about your health, only to keep you coming back for more!

Another point would be that the same applies for the stimulant caffeine, artificially assimilated drinks of caffeine and other additives, aka energy drinks, have been shown time and time again to have potentially adverse health implications.

Then we have caffeine in its natural form such as that from coffee and tea, which instead has an incredible amount of positive research concerning their health benefits. There is plenty of positive health benefits shown in research on tobacco and nicotine as well.

Like previously mentioned, rolling up a cigarette containing pure tea leaf or ground coffee beans is then not so different from pure tobacco, after all, nicotine is a stimulant very similar to caffeine as we will discuss later in the article.

Likely the only thing about tobacco that can be problematic is the addiction aspect. It highjacks the brain's pleasure and reward centers which if not sensibly used over time can become a chronic addiction.

Now, how unhealthy is the addiction?

But just because a habit is addictive does not necessarily make it damaging to the body.

Coffee consumption is also addictive, and many people can't see themselves starting the day without that morning cup of joe. Even quitting chronic coffee consumption can produce side effects from the addictive properties of caffeine.

Still coffee is far from unhealthy, it’s been shown in lots of research studies to prevent chronic health issues, boost cognitive function and improve metabolism.

What is important to note is that it is not the substance in itself that is engineered to make you crave it. When you consume it, the body regulates different systems to reach homeostasis with the substance (which builds a tolerance to it).

When the substance is no longer consumed, the body has to regulate back again. You become adapted to using the substance, not addicted per say.

This new state requires you to keep consuming the substance to keep this adaptation stable.

It’s not so different from the need we have for food, and if we do not consume it, you will suffer the side effects of low blood sugar, energy levels, and raging hunger. Your body is adapted to use food for its energy needs. Your body can also be adapted to a high metabolism running on caffeine.

When you’re no longer addicted/adapted to caffeine or nicotine in the short term, there might still be cravings for the substance. Often desires are a sign of an imbalance, your body lacks something and it is trying to tell you how to fix it by any means it has learned so far.

This is why you always want to reach for that coffee when you’re tired or cigarette when you’re stressed, they correct the chemical imbalance because the effects they have on your body, and your body knows this. It’s no different than how food corrects your problem of hunger and refills your energy stores.

We will dig deeper into the exact chemical reactions that happens later in this article, but it’s safe to say that don’t believe the stigma that the tobacco plant is intrinsically evil.

Now when we have established that the tobacco plant might be falsely crucified, let’s dig more in-depth on the nicotine contained in tobacco, and it's correlation with caffeine, the most popular stimulant in the world.

In reality, what tobacco is, is merely just another herbal stimulant, among many such for example tea, coffee, chocolate, betel, kratom, khat, and coca leaf. All of which has shown few adverse side effects when used in their natural form.

There are quite a few correlations in effects between caffeine and nicotine, we outline them in general below but will also discuss them more in detail later in the article:

• Caffeine stimulates AMPK (AMP-activated protein kinase) in skeletal muscle and nicotine activates AMPK as well. This comes with pro-metabolic effects.
• In this study caffeine was demonstrated to boost daily energy expenditure by 10%, similar results were also obtained in the following study on nicotine. Overall amounting to an average increase in energy expenditure by about 200kcal per day.
• Chronic nicotine use, as well as caffeine consumption, have both been shown to lower growth hormone and other pituitary hormones such as TSH. Lower growth hormone levels (while not being deficient) has been implicated in life extension.
• Nicotine increases levels of Dihydrotestosterone (DHT, the most potent androgen) similarly to caffeine which also increases androgenic stimulation resulting in higher levels of testosterone and DHT.
• Both nicotine and caffeine increase levels of important neuro-steroids such as Pregnenolone, Progesterone, and Allopregnanolone which are likely responsible for much of their stimulatory effects.
• Nicotine and caffeine are neuroprotective against Parkinson’s disease.
• Both nicotine, as well as caffeine, are stress adaptive substances which cause an increase in stress hormones initially, but from chronic use down-regulate the stress response and show improved stress biomarkers to all forms of stress. This is likely why people increase their consumption of these substances during times of increased stress.

It should be clear to you by now why smokers often like a cup of coffee with their cigarette since both substances are very similar in effects and highly synergistic. It’s no wonder why these are among the most consumed “drugs” in the world.

While caffeine indeed is the safest substance of the two, nicotine is probably the most beneficial and potent one in the short term. Let’s take a closer look at nicotine effects.

One of the primary beneficial effects of both caffeine as well as nicotine is their ability to boost levels of catecholamines such as dopamine. Nicotine is by far more potent in this regard compared to caffeine.

Dopamine is one of the most critical neurotransmitters (a messenger molecule) in the body and is responsible for feelings of pleasure, happiness, and motivation. Because of this, it has been deemed the feel-good neurotransmitter.

In a normal situation, dopamine levels increase in response to positive experiences such as for example social interaction, pleasurable activities or hobbies, winning, sex, money, movies, video games and tasty food. In other words everything enjoyable in life! It serves as a pleasure cue and reinforces us to seek out these positive experiences more often.

Boring activities, on the other hand, will not stimulate us enough to want us to seek them out further because of the lack of dopamine release we get from them.

The pleasurable feelings derived from winning an award, for example, can increase our motivation to work harder to win another one. Success feeds success, same as failure feeds failure (losing gives us no dopamine reward and hence decrease our motivation to play again).

On the far end of the spectrum, an overload of dopamine is what is responsible for the pleasurable effects and euphoria that can be derived from recreational drugs such as amphetamine and cocaine. This is what makes these drugs so addictive.

ADHD and ADD is primarily a state where you are not sensitive enough to dopamine from everyday activities and hence find it hard to focus or stay interested in them. Adderall is the most commonly prescribed pharmaceutical for this which is just a pill with a fancy name that contains amphetamine.

There are also many other health problems such as high prolactin levels that can chronically decrease your levels of dopamine and hence make regular pleasurable experiences not feel pleasurable anymore. This often manifests as fatigue, anxiety, lack of motivation and even sexual dysfunction.

Many guys might also think that porn is a harmless pastime but porn stimulates our dopamine pathways in a similar way as drugs which is what makes porn so addictive. Gambling or video games in excess is no different. They all make regular life less exciting by desensitizing our dopamine receptors.

The problem with the pleasure derived from drugs, porn and gambling are that it also reinforces a bad habit for us that has potentially adverse effects on our quality of life. Drug addiction is no joke, and neither is dept or erectile dysfunction from chronic masturbation to porn.

We are all sensitive to this by different degrees because of our genetic sensitives in an enzyme called COMT which breaks down dopamine at different speeds.

Dopamine is essential and something we want more of to increase our enjoyment in life and also to reinforce what matters to us.

Mostly harmless substances such as caffeine or even nicotine are safer ways of offering us a direct route to increase our dopamine levels directly at our convenience.

This is useful to boost motivation and productivity in situations we might otherwise not experience as pleasurable such as from work or exercise. Maybe you are now beginning to see why caffeine is the number #1 most popular substance to increase productivity in the workplace.

Nicotine when dosed at the right time, can act as a biohack to reinforce us to seek out the situation we consume it in. An excellent example of this is why smokers crave cigarettes more in social situations such as when drinking alcohol, they have essentially tied it’s consumption to the situation. Social smoker anyone?

This is why it is said that nicotine highjacks the dopamine reward pathway in the brain, which does not necessarily have to be a bad thing depending on how you use it.

All in all, stimulants such as nicotine or caffeine increase stimulation to and from activities and offer a quick and effective way of boosting and maintaining levels of catecholamines. This also has implications in stress as we will discuss later in the article.

One of the primary benefits of nicotine besides its nootropic qualities is its ability to increase one's metabolic rate.

It’s is known by most people that caffeine increases your metabolic rate too and many use caffeine pills or energy drinks for weight loss purposes for that particular reason.

Nicotine is thermogenic and has the same ability as caffeine to increase the basal metabolic rate and body temperature. It has been shown in multiple studies such as this one and this one that it produces an increase in energy expenditure of about 6-10%.

This will equal to around 10kg or 22lbs weight loss on a yearly basis if calorie consumption stays the same.

In fact, many bodybuilders use nicotine patches or gums during cutting to help burn fat and keep the metabolic rate high even while restricting calories. A combination of both caffeine and nicotine would be ideal for this purpose.

Metabolic rate is essential and something we emphasize here at Anabolic Health. It enables you to produce more energy, recover faster, tolerate more stress and burn fat effortlessly.

Remember that a relaxed state is a high energy state, where you effortlessly have enough resources to tackle any problem life throws at you.

There is a misconception today that the lowering of the metabolic rate with age is a marker for life conservation. The wear and tear model of longevity is predominant and that we all have a fixed lifespan and that everything that can slow us down can help us live longer. There is a lot that points to that this is not necessarily true.

Even if this was true, do we choose optimal performance or reduced performance in the hopes of a longer life? Is a long life with less than ideal performance worth more than a slightly shorter life where you perform at your best?

A good example is the high metabolic rate we have in our youth when our health is at its peak, and we seem to be able to eat almost anything without putting on much weight.

There have also been done some exciting research that few people talk about:

• "Organisms as different as yeasts and rodents show a similar association of metabolic intensity and life-span. A variety of hamster with a 20% higher metabolic rate lived 15% longer than hamsters with an average metabolic rate (Oklejewicz and Daan, 2002)."

• "Individuals within a strain of mice were found to vary considerably in their metabolic rate. The 25% of the mice with the highest rate used 30% more energy (per gram of body weight) than the 25% with the lowest metabolic rate, and lived 36% longer (Speakman, et al., 2000)."

I don’t argue that nicotine should then be seen as a longevity agent, especially not smoking, even though there are also quite a few cenetarian smokers who live well up into very old age. This should be enough to stir up some controversy.

What I argue is that increasing the metabolic rate should be seen as a healthy core principle in maintaining health and performance, and there are quite a few ways to do that, two of them being caffeine and nicotine.

All in all, both caffeine and nicotine are associated with leaner body mass and lower incidence of obesity because of their effects on the metabolic rate.

Let’s start off with some background so that you fully understand the potential benefits of both caffeine and nicotine on pituitary hormones. Hang in there as we will go for a deep dive.

• “On the level of the whole organism, stress causes overactivity of the pituitary, and removal of the pituitary extends life, and retards the hardening of the extracellular connective material
  (Everitt, et al., 1983).”

• “Several of Everett's experiments strongly pointed to the prolactin-growth hormone family as the aging factors. Removal of the pituitary caused retardation of aging similar to food restriction.
  (Ray Peat Ph.D.)"
  

We already know for a fact that reduced levels of growth hormone in different types of animals and mammals can increase lifespan, as shown in research. This primarily has to do with levels of IGF-1 (insulin-like growth factor 1) which belongs to the growth hormone family and is controlled by the pituitary.

Vegan diets are trendy nowadays, and while being far from optimal nutritionally (we do not condone veganism at all), they do hold some merit in life extension mechanism by reducing levels of IGF-1 since they restrict protein.

The problem is that it has nothing to do with being vegan, to begin with. Protein or even calories can be restricted on any diet with similar effects. Plant protein same as animal protein contains amino acids that increase levels of IGF-1, it is just that vegan foods are more naturally restricted in protein intake.

The problem with restricting protein is that it has been done without problems in younger populations, but in older people, it tends to cause adverse effects. This makes sense since when you’re older, it is naturally harder to maintain muscle mass and growth hormone levels also decline with age.

Protein is vital for maintaining thyroid health (metabolism) and body composition, hence restricting protein is an awful way of trying to extend life. It will leave you skinny and feeling cold and miserable.

Growth hormone is released in stressful situations such as strength training and fasting. But keep in mind that this type of increase in growth hormone is transient and has no real drawbacks from a longevity aspect unless overtraining or too long periods of fasting (at which other problems will inevitably develop as well).

Other pituitary hormones that are also increased by stress are TSH, Prolactin, FSH, and ACTH.

• TSH (Thyroid Stimulating Hormone) is a signaling hormone that is released to stimulate the thyroid to produce more thyroid hormones. A lower TSH reading on your blood test will indicate that you are in good metabolic health and have adequate amounts of thyroid hormones. In other words, we want to keep this one low.
• Prolactin can be viewed as a stress hormone that suppresses dopamine. It increases with age and is a prime driver of sexual dysfunctions, gynecomastia, and hair loss when presented in excess. Prolactin is a big key player in male health and something we want to control at all cost.
• FSH (Follicle-Stimulating Hormone) increases aromatase activity which increases testosterone conversion into estrogen, leaving us with less testosterone. It’s also increased with age or stress. Remember that aging can be regarded as a stress factor as well.
• ACTH (Adrenocorticotropic Hormone) stimulates stress hormone production (cortisol) as well as androgen production.

So what does all of this have to do with nicotine you ask?

• "Chronic nicotine consumption may also lead to lower responses of other stress hormones (ACTH, prolactin, growth hormone) to a variety of stimuli" (Kirschbaum et al., 1994).

In research, nicotine shows mixed results on pituitary hormones, sometimes increasing and other times decreasing. What seems to be the case though is that chronic intake of nicotine reduces levels of pituitary hormones by an adaptive mechanism.

• "Acute nicotine administration stimulates prolactin release (Wilkins et al., 1982; Rasmussen, 1995). However, serum prolactin levels are significantly lower in both male and female chronic smokers who smoke more than 10 cigarettes per day (Andersen et al., 1984). This apparent discrepancy could be explained by a similar mechanism to that with ACTH (Fuxe et al., 1989)."

In more straightforward terms, nicotine acutely increases them, but with chronic use the body down-regulates production. This is very similar to the effects of caffeine on pituitary hormones as well.

We all know that without any tolerance to caffeine, a strong cup of coffee might make you jittery because you are not used to it. But with chronic consumption, you adapt, and your body gets used to the effects (building tolerance).

So same as with caffeine, nicotines beneficial effects on reducing pituitary and stress hormones only comes from chronic daily use.

Let’s get down to the particulars.

• "A secondary finding observed in the overall study group (primarily in females) was that nicotine caused a 29% median decrease in serum growth hormone (P =.02)."
  Acute effects of nicotine on serum glucose insulin growth hormone and cortisol in healthy smokers. - PubMed - NCBI

• "Nicotine significantly reduced serum prolactin and TSH levels, and after H 44/68 it also reduced LH and FSH serum level."
  Involvement of cholinergic nicotine-like receptors as modulators of amine turnover in various types of hypothalamic dopamine and noradrenaline nerv... - PubMed - NCBI
  

And here’s caffeine.

• "Caffeine lowered serum TSH and GH in a dose-dependent manner with ED50 values of 30 and approximately 50 mg/kg, respectively."
  Effects of caffeine on anterior pituitary and thyroid function in the rat. - PubMed - NCBI

By far the most beneficial effects of nicotine on pituitary hormones is inhibition of prolactin.

As we already mentioned prolactin increase with stress, but also prolactin is what is responsible for the refractory period after sex when you orgasm.

Gynecomastia and hair loss are also primarily driven by prolactin, and the best way to treat them is by using prolactin inhibitors.

Here’s what the research says on nicotines powerful influence on prolactin.

• "Nicotine was also observed to yield a concentration-dependent inhibition of the stimulation by thyrotropin-releasing hormone (TRH) of PRL promoter activity, implying that nicotine can also interfere with the hormonal regulation of the PRL gene."
  Nicotine acts directly on pituitary GH3 cells to inhibit prolactin promoter activity. - PubMed - NCBI

• "Chronic nicotine treatment under the present conditions did not significantly alter serum levels of corticosterone and reduced prolactin serum levels in sham-operated rats."
  Chronic nicotine treatment increases dopamine levels and reduces dopamine utilization in the substantia nigra and in surviving forebrain dopamine nerve... - PubMed - NCBI
  

• "Nicotine treatment and to a minor degree also acute intermittent exposure to cigarette smoke produced a reduction in serum prolactin, LH and TSH but not in serum FSH, vasopressin and testosterone levels."
  Involvement of D1 dopamine receptors in the nicotine-induced neuro-endocrine effects and depletion of diencephalic catecholamine stores in the male... - PubMed - NCBI
  

• "Chronic daily nicotine administration induced significant changes in serum corticosterone, serum prolactin, MBH TH mRNA, and MBH POMC mRNA concentrations that tended to persist through day 3 of withdrawal; serum prolactin and MBH POMC mRNA concentrations were suppressed whereas serum corticosterone and MBH TH mRNA concentrations were stimulated."
  Effects of chronic nicotine treatment and withdrawal on hypothalamic proopiomelanocortin gene expression and neuroendocrine regulation. - PubMed - NCBI
  

We will discuss nicotine effects on ACTH more in detail later concerning nicotine and the stress response.

Two of the metrics we most often recommend men to keep track of is their prolactin and estrogen levels. Prolactin is usually a good indicator of levels of estrogen in the body since estrogen stimulates prolactin secretion and both can be considered synergistic hormones of stress and aging.

"Treatment of ovariectomized rats with estradiol benzoate (25 micrograms/kg, sc) daily for five days resulted in a marked elevation of the serum PRL (prolactin) concentration."
[1]Role of estrogen in the dopaminergic control of prolactin secretion. - PubMed - NCBI

If you have too high levels of estrogen, this condition is called estrogen dominance and is common in both men and women.

Sharp declines in the hormone progesterone (which opposes estrogen) during female menopause is responsible for the estrogenic side effects of hot flashes, mood swings and weight gain so common in women in older age.

Men also suffer from declining levels of progesterone during aging as well as increased production of estrogen in fat cells from obesity and consumption of estrogenic foods such as beer.

Phytoestrogens and high levels of body fat increase the expression of aromatase enzyme in the body which is the enzyme responsible for converting testosterone into estrogen.

These conditions can all be prevented by monitoring your prolactin and estrogen levels over time as well as by taking the necessary lifestyle precautions needed to lower them if necessary.

There are safer longterm solutions as well as quicker and stronger short-term therapies to lower prolactin and estrogen available. Nicotine and tobacco fall into this category of some of the most potent natural treatments.

If you are an obese man with poor body composition and gynecomastia, oral or transdermal nicotine would be a healthy habit for you to pick up since your current state of health would be much worse to stay in rather than any of the potential risks implicated in consuming nicotine.

In the above case, nicotine would work towards reducing estrogenic activity in your body by blocking aromatase activity as well as increasing the metabolism enabling you to burn more body fat and eventually reverse your poor state of hormonal and metabolic health.

Let’s further dive into what the research says to prove these claims.

Below are two excellent studies that show decreased levels of circulating estrogens both from internal estrogen production as well as orally administered estrogens in the case of HRT.

• "However, it has been proven that, depending on the type, duration and intensity of nicotine consumption, smoking can reduce or completely cancel the efficacy of orally administered estrogens."
  Smoking, estradiol metabolism, and hormone replacement therapy. - PubMed - NCBI

• "These findings suggest that some nicotinic alkaloids directly inhibit aromatase. This mechanism may explain, in part, the decreased estrogen observed in women who smoke."
  https://www.jci.org/articles/view/112494
  

Aromatase inhibition by nicotine will also translate into reductions in prolactin levels because of lower amounts of estrogen being available. Increased catecholamine release also plays a part in this as well as lower TRH (Thyrotropin-releasing hormone) which also has a stimulatory effect on prolactin release but is inhibited by nicotine.

Another less common benefit that most people do not know about tobacco is that it is a potent antiviral, anti-fungal, and anti-bacterial compound. Same as caffeine, nicotine is produced in the tobacco plant as a protective compound to ward off viral and fungal diseases.

During the Great Plague of London in 1665-1666, which killed roughly 100 000 people with a 40% death rate, tobacco was a known preventative.

From the History Learning Site, “Cures for the Plague” website:

• “Those employed in the collection of bodies frequently smoked tobacco to avoid catching the plague.”

• “For personal disinfections, nothing enjoyed such favor as tobacco; the belief in it was widespread, and even children were made to light up a reaf in pipes. Thomas Hearnes remembers one Tom Rogers telling him that when he was a scholar at Eton in the year that the great plague raged, all the boys smoked in school by order and that he was never whipped so much in his life as he was one morning for not smoking. It was long afterward a tradition that none who kept a tobacconist shop in London had the plague.”

Tobacco has been shown to inhibit the following viruses by pretreatment:

As well as the following pathogens:

This study further highlights tobacco’s anti-bacterial effects:

• "These studies indicate that chronic exposure to tobacco smoke does not impair, and in fact may stimulate, the host defenses of the lung, as evaluated by in vivo and in vitro pulmonary alveolar macrophage function."
  The effect of chronic exposure to tobacco smoke on the antibacterial defenses of the lung

While most of these studies were done on smoking tobacco, it is possible to reach the same levels of active alkaloids from oral tobacco such as snus as well.

Many people are under the impression that the only way substances such as nicotine and caffeine are stimulating and beneficial is because they increase the levels of catecholamines, but this is not true.

They also increase levels of neurosteroids such as Pregnenolone, Progesterone and DHEA (hormones) and these can be seen as steroids for your brain, increasing motivation, mood and improving overall brain function and memory.

These hormones are associated with youth since we have the highest levels of them during our younger years when our health is also at its peak. They are often supplemented with as anti-aging therapies since their levels decline more and more the older we get.

Pregnenolone is the building block of all hormones and progesterone is probably the most protective hormone in the body which especially increases in women during pregnancy to protect the fetus.

It is thought from research that it is the increase in these neurosteroids that are responsible for the positive cognitive effects of caffeine but also what makes it anxiogenic in excess.

Studies have shown that different metabolites of pregnenolone can both have anxiety reducing as well as anxiety increasing effects depending on their dosage:

• "The effects on anxiety of PREG, PREGS, DHEA, and DHEAS are less clear than those of ALLO. PREG has been reported to induce anxiogenic activity in mice tested in the plus-maze model.8 In the same study, PREGS produced a biphasic action, with a low dose (in the nanomolar range) inducing anxiolytic effects and a high dose (in the micromolar range) an anxiogenic response."

This likely explains why people react so differently to nicotine and caffeine where often smaller doses reduce anxiety and improve mood, while higher dosages can increase it. Either way, the net effect of increasing neurosteroids is highly beneficial in almost every regard.

It is known that progesterone decreases self-administration of nicotine and the urge to smoke (such as in women during pregnancy when progesterone levels run high). This is suggestive for that nicotine compensates for low progesterone and likely increases levels of progesterone.

This was further proven in a study that shows that similar to caffeine, nicotine also increase the neuro-steroid levels of Pregnenolone, Progesterone, and Allopregnanolone (a pregnenolone metabolite).

These neurosteroids are also implicated in drug withdrawal from long-term drug use, so it is likely that withdrawals experienced from caffeine and nicotine work similarly.

The benefits of progesterone are immense, such as reducing anxiety, improving memory, protecting brain cells, and even preventing epileptic seizures. There are a lot of research done that show similar effects from nicotine which is likely from its ability to increase levels of progesterone.

• "In the present study, male Wistar rats exposed a relatively low dosage of nicotine (0.35 mg/kg every 12 h) for 14 days demonstrated improved memory performance (assessed in two separate water maze testing methods) when compared with controls."
  Repeated nicotine exposure in rats: effects on memory function, cholinergic markers and nerve growth factor. - PubMed - NCBI

• "Cotinine (Nicotine metabolite) reduced Aβ deposition, improved working and reference memories, and inhibited Aβ oligomerization in the brains of transgenic (Tg) 6799 AD mice."
  Cotinine reduces amyloid-β aggregation and improves memory in Alzheimer's disease mice. - PubMed - NCBI

• "Cotinine-treated mice displayed better performance than vehicle-treated cohorts on the working memory task, the radial arm water maze test. Besides, with or without chronic stress exposure, cotinine-treated mice engaged in fewer depressive-like behaviors as assessed using the tail suspension and Porsolt's forced swim tests."
  "Taken together, our results show for the first time that cotinine reduces the negative effects of stress on mood, memory, and the synapse."
  Cotinine reduces the depressive-like behavior, working memory deficits, and synaptic loss associated with chronic stress in mice. - PubMed - NCBI

• "In an open study, nicotine patches reduced seizures..."
  Nicotine is structurally similar to nicotinic acid (Niacin) which has demonstrated anti-epileptic effects.
  ​Nicotine as an antiepileptic agent in ADNFLE: an N-of-one study. - PubMed - NCBI
  

Also, Nicotine, Caffeine and Progesterone Are Neuro-Protective Against Parkinson's:

Current evidence for neuroprotective effects of nicotine and caffeine against Parkinson's disease. - PubMed - NCBI

Progesterone prevents depression-like behavior in a model of Parkinson's disease induced by 6-hydroxydopamine in male rats. - PubMed - NCBI

Association of coffee and caffeine intake with the risk of Parkinson disease. - PubMed - NCBI

Since we know that steroids such as progesterone and DHEA are synthesized in the body from cholesterol, I hypothesize that the reason we also see a positive effect from nicotine on cognitive function in hypothyroidism is that nicotine offsets the underproduction of them.

Also as an end note, it is worth to mention that nicotine and caffeine are not among the only substances that work by this mechanism, Panax Ginseng aka Korean Ginseng has also been shown to increase levels of neurosteroids.

Chronic stress decreases levels of dopamine (the neurotransmitter of pleasure) since stress is only derived from situations that we do not find pleasurable (which does not cause an increase in dopamine).

Dopamine is not the only catecholamine. From dopamine, the body can further manufacture epinephrine (adrenaline) and norepinephrine. These are more related to the fight or flight response as they quickly mobilize and energize us to take action in a stressful situation.

A chronically overactive stress response hence deplete dopamine (and our mental state of pleasure) by converting it to too much adrenaline all the time to fight the stressor.

Although it's clear that smoking is in general stressful for the body and will in the long term cause increases in stress hormones, the consumption of isolated nicotine or oral tobacco does not come with these same effects.

Oral and transdermal nicotine works in similar ways to caffeine in reducing stress but being much more potent in this regard. Nicotine does this by an adaptive mechanism were initial nicotine use will increase the stress hormone cortisol and levels of adrenaline, but with continued use, the body adapts and downregulate their production (reducing pituitary function).

This also translates to reduced stress hormone output during times of regular life stress. It is one of those cases were similar to vaccination, a little bit of the poison can make you immune to large amounts of it.

The following two studies prove this adaptive effect in both nicotine and caffeine:

• Plasma ACTH and cortisol levels after oral administration of nicotine (chewing gum containing nicotine 2 mg) in short and long time (10 and 45 min) were studied in smokers and non-smokers. Non-smokers after short time administration showed a significant rise in ACTH and cortisol. No modifications were seen in the other groups of subjects.
  [1] http://www.ncbi.nlm.nih.gov/pubmed/2550038

• "Chronic caffeine intake decreases circulating catecholamines and prevents diet-induced insulin resistance and hypertension in rats."
  http://www.ncbi.nlm.nih.gov/pubmed/21733336

One of the best perks of nicotine vs. caffeine is it’s shorter half-life. It is possible to use nicotine in the evenings and still get good restful sleep at night which is usually not the case with caffeine. Nicotine has a half-life of about 2 hours vs. caffeine with a half-life of 6 hours.

For body composition improvements, combining nicotine with caffeine is the best since they are highly synergistic for increasing the metabolic rate. We suggest 1 pouch of snus (oral tobacco) and 1 cup of strong coffee 3x a day for best results.

Nicotine also increases the rate at which the body metabolizes caffeine which makes it even easier to use the substances together without affecting sleep, although you should still try to cut all caffeine off by 6 hours before bedtime to make sure.

If you are interested in trying nicotine, make sure you keep these potential side effects and recommendations in mind first for “safer” tobacco/nicotine use:

Before you decide to give nicotine or tobacco a shot, ask yourself this, do you have good self-control? Do you often crave junk food, porn or alcohol and find it hard to not give in to these cravings? If yes then nicotine is probably not a good idea for you as it is indeed addictive even in oral/topical form, although not remotely as addictive as smoking. 

Do you have metabolic issues such as poor digestion, obesity, estrogen dominance or hypothyroidism? Then yes nicotine might be able to help you.

In the case of hypothyroidism, nicotine should only be used short-term or on an as-needed basis since while it’s been shown that nicotine can prevent cognitive issues from low thyroid function, longterm chronic use will likely result in worse thyroid function once you try to stop its use.

Likewise, if you're using it for weight loss or cutting it is important not to do it long term as well as taper it's use. Metabolism is bound to slow down once you stop using it so do it in increments, keep track of calorie intake and weight, so you don’t get rebound as well as increase caffeine intake to compensate.

This one is impossible to avoid since any time you use a substance that powerfully increases levels of catecholamines, you will get vasoconstriction and decreased blood flow to specific areas of the body because more dopamine also means more adrenaline. Many smokers are familiar with this and suffer from cold hands and feet on a daily basis.

Our best recommendations for this is to eat a diet high in foods that are great for your cardiovascular system and blood vessel health. Food such as dark chocolate and pomegranate are the superstars when it comes to this. 50g dark chocolate per day should make a good impact as well as being quite enjoyable as a daily habit.

Another good option is consuming low dose daily aspirin or a full-strength aspirin tablet every 2-3 days. Aspirin prevents blood clots and has been shown to improve endothelial health.

If you decide to consume aspirin, also make sure you are getting adequate Vitamin K from a supplement to prevent excessive blood thinning effects. Crushing the aspirin tablets and consuming them with food will also avoid any potential gut issues. If you take these precautions, then aspirin is a very safe supplement to use on a long-term basis.

By the way salicylic acid (aspirin) is a natural compound found in some plants and ripe fruit, so not originally synthetic such as the likes of paracetamol and ibuprofen.

Also make sure that unless you are trying to lose weight, consume enough calories because nicotine is a metabolic booster and under eating, while simultaneously boosting metabolism will increase adrenaline no matter what since the body needs to break down fat and protein to compensate for the lack of energy intake. This increase in adrenaline will also increase vasoconstriction.

Nicotine increases free fatty acids in the blood since it is very good at breaking down fat in the body. Keep in mind though that liberating free fatty acids chronically will inhibit oxidative metabolism and health wise it is not very good long-term, so keep dieting with nicotine short term and then resume maintenance calories.

As we have already established, when it comes to tobacco products it is often the additives in them that are killing you rather than the plant in itself. Smoking is all negatives though so we never recommend this way of consumption.

The superior choice on the market right now is Swedish snus, which is an oral tobacco product. The tobacco is packed into small pouches made from plant materials that you put under your upper lip, and the nicotine absorbs through the gums over time.

Not only does this way of consumption not come with any of the negatives of smoking, but it is also much less addictive because the nicotine is absorbed slower and you avoid the sharp ups and downs in catecholamines.

I have used snus for 1-3 months at a time on a daily basis in a similar dosage as of the amounts of nicotine contained in 3-5 cigarettes. I found no problem quitting this habit and experienced close to zero withdrawal other than some mild cravings the first three days, which were easy to extinguish with an extra cup of coffee.

Here are some fascinating facts about why Swedish tobacco products are superior choices:

A lot of the research studies done on the use of oral tobacco and associated health risks have been done on snus or chewing tobacco made in other countries than Sweden that does not impose these strict tobacco manufacturing laws.

This is why for example some studies have found an increase in throat cancer risk while others (such as those studies done on specifically Swedish snus) did not see any correlation.

We will not go into all the specifics here as it would take an entire article by itself, but we suggest you check out the "ENVIRON Review of the Scientific Literature on snus."

• Read the ENVIRON report (PDF)