Does Nicotine Increase Testosterone Production? Examining the Evidence and Impact

When you hear the word "nicotine," you probably think of cigarette smoking and possibly addiction. But there’s a question that comes up surprisingly often about its impact: does nicotine increase testosterone?

How could something like cigarette smoking also increase a hormone linked to vitality and masculinity? It seems illogical. 

The connection between testosterone and nicotine isn't nearly as simple as you might think. In their investigations, researchers found that some studies suggest short-term increases in testosterone levels. Others suggest long-term use may have the opposite effect. If you have considered quitting smoking, its effects on your testosterone levels could just convince you.

Key Takeaways

• Nicotine may raise testosterone levels temporarily by activating the luteinizing hormone (LH). Long-term cigarette smoking, however, has been connected to hormone imbalance and decreased testosterone levels.
• Nicotine enters the bloodstream and interacts with the endocrine system, potentially harming the testosterone-producing Leydig cells in the testes. Nicotine's effects are not limited to the lungs; they can also influence your body's production of sex hormones.
• There are inconsistencies in the research findings. Large longitudinal studies, such as the Massachusetts Male Aging Study, demonstrate that long-term smoking tends to reduce testosterone levels, despite some cross-sectional studies reporting higher testosterone levels among smokers.
• Long-term smoking and nicotine use are linked to male infertility, lower sperm counts, and lower sperm quality.
• Other lifestyle factors that affect testosterone include body weight, stress, alcohol consumption, and diet. Hormonal changes can be caused by several factors, including nicotine.
• Due to conflicting results, scientists advise conducting additional research, particularly longitudinal studies and meta-analyses, to investigate the long-term effects of nicotine on testosterone and fertility.

The First Stop for Nicotine: The Endocrine System

Nicotine doesn't stay in your lungs when you smoke a cigarette or e-cigarette. It enters your bloodstream through inhalation and interacts with your endocrine system. The endocrine system regulates how nicotine affects the body and maintains hormone production and balance within the body.

The luteinizing hormone instructs the testes when to produce testosterone. Some sources indicate that nicotine causes a brief increase in LH, which can increase testosterone levels (Trummer et al., 2017; Rellini et al., 2012; Holmboe et al., 2018). 

Trummer and others (2017) combined data from several studies and discovered that smokers had higher total testosterone levels than non-smokers. Holmboe and colleagues (2018) showed that smoking was associated with increased testosterone and disruptions in other reproductive hormones such as follicle-stimulating hormone (FSH) and inhibin B. FSH and inhibin B regulate how the testes produce sperm in men. Rellini et al. (2012) reported a modest positive association between smoking and testosterone concentrations.

How Does Cigarette Smoking Affect Testosterone Levels?

Cigarette smoke introduces thousands of chemicals alongside nicotine. Over time, this mix can damage the cells in the testes responsible for making testosterone. So even if you experience a short-lived boost in testosterone, long-term use tends to tilt the scales in the other direction, leading to a decrease in testosterone levels and even decreased sperm counts.

If you look at large observational studies, including research on young men and middle-aged smokers, this pattern appears. Some smokers had slightly higher testosterone levels early on, but the longer they smoked, the more often they experienced a decrease in testosterone.

Smoking and Testosterone: What the Research Says

One of the most cited sources about the relationship between testosterone and nicotine is the Massachusetts Male Aging Study. This project followed men over many years to evaluate how smoking status, body mass index, and other lifestyle factors affected hormones. The results were published in a systematic review. 

The data showed that chronic smokers were more likely to have decreased testosterone levels over time, highlighting the need for further analysis of observational studies.

That said, there is also research indicating that nicotine may increase testosterone levels. Some studies with smaller sample sizes identified smokers with higher testosterone. Researchers aren’t sure why the research shows conflicting results.

One theory suggests the differences in nicotine metabolic phenotypes. In simple terms, that means how quickly each person’s body breaks down nicotine.

Other hypotheses are concerned with how much people smoke and whether they use e-cigarettes or oral tobacco instead of cigarettes. 

E-cigarettes, for instance, provide nicotine without burning, which may make nicotine withdrawal easier. The fact that they contain nicotine means they can still impact hormone levels.

The Effects of Smoking on Androgen Levels

Nicotine comes with a price, even if it temporarily increases testosterone. Long-term smoking is a known risk factor for lower sperm counts. Quitting smoking may mitigate many health dangers, including male infertility.

Some men don’t think about how nicotine could affect testosterone levels until they start trying for a family. They might assume that smoking only affects lung health or raises their risk of cancer. But over the years, research has made it clear that tobacco smoke (and nicotine) can harm testicular function and affect testosterone production, reducing fertility.

Interestingly, when men quit smoking, their testosterone levels often rise again. Sperm counts can improve, too. Smoking cessation, or quitting smoking, doesn’t erase all the damage, but it’s one of the most reliable ways to move testosterone levels back towards equilibrium.

Why the Research Is So Confusing

The research on smoking and testosterone appears to show conflicting results. The reason for this is the way research has been conducted. Some projects evaluate testosterone levels at a single point in time, like a snapshot. Other studies, like observational studies, follow participants for years and can gather more data about the effects of nicotine on testosterone.

Cross-sectional studies may catch that initial increase in testosterone that happens shortly after nicotine exposure. These studies may appear to support theories that nicotine use leads to higher testosterone. But longitudinal research tends to show that nicotine decreases androgen levels in men.

Lifestyle Factors and Testosterone Production

There are many variables that can influence testosterone levels. People don’t just smoke. They also drink alcohol, gain or lose weight, and experience stress. All these factors can interfere with hormone levels.

Animal studies have helped fill in the gaps to create some understanding of the relationship between smoking and testosterone. Rodent models show that nicotine damages Leydig cells, which produce testosterone.

Even though the evidence suggests that nicotine gradually reduces testosterone levels, many questions remain. Hence, experts frequently encourage more meta-analysis of observational research, especially studies that track men who quit smoking or use e-cigarettes instead of cigarettes.

Should You Worry About Your Testosterone Levels?

If you smoke or use nicotine products, you’re probably wondering whether you should be concerned. The short answer: if you care about your fertility, energy, or overall health, including the effects of nicotine use, it’s worth thinking seriously about quitting smoking.

Many men don’t notice subtle drops in testosterone until they start experiencing symptoms. Symptoms like fatigue, mood changes, and reduced libido may indicate lower testosterone levels.

While nicotine isn’t the only factor that affects hormone levels, it’s one you can control. The advantages of quitting go well beyond testosterone and can positively influence androgen levels. Smoking cessation can improve lung function, reduce your risk of cardiovascular disease, and increase your chances of living a longer life.

If you’ve experienced ongoing fatigue, low mood, or changes in sexual health, it may be worth learning more about the symptoms of low testosterone.

Recognizing these signs early can help you decide whether testosterone treatment is right for you.

References

Feldman, H. A., Longcope, C., Derby, C. A., Johannes, C. B., Araujo, A. B., Coviello, A. D., Bremner, W. J., & McKinlay, J. B. (2002). Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts Male Aging Study. Journal of Clinical Endocrinology & Metabolism, 87(2), 589–598.

Trummer, C., Habib, F. K., Haas, J., Pichler, R., & Horninger, W. (2017). Impact of cigarette smoking on serum testosterone and sex hormone-binding globulin in men: a meta-analysis. Andrology, 5(5), 902–912.

Kapoor, D., Goodwin, E., Channer, K. S., & Jones, T. H. (2007). Testosterone replacement therapy improves insulin resistance, glycaemic control, visceral adiposity and hypercholesterolaemia in hypogonadal men with type 2 diabetes. European Journal of Endocrinology, 154(6), 899–906.

English, K. M., Mandour, O., Steeds, R. P., Diver, M. J., Jones, T. H., & Channer, K. S. (2000). Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms. European Heart Journal, 21(11), 890–894.

Dai, J. B., Wang, Z. X., & Qiao, Z. D. (2015). The hazardous effects of tobacco smoking on male fertility. Asian Journal of Andrology, 17(6), 954–960.

Zhang, J., Jiang, X., & Zhang, L. (2017). Nicotine-induced dysfunction of Leydig cells is associated with oxidative stress and may lead to lower free testosterone levels . Toxicology Letters, 275, 28–35.

Holmboe, S. A., Skakkebæk, N. E., Juul, A., Andersson, A. M., Linneberg, A., & Jensen, T. K. (2018). Influence of smoking on serum inhibin B, FSH and testosterone levels in 1,215 Danish men. Fertility and Sterility, 109(6), 1184–1190.e3.

Rellini, A. H., McCall, K. M., Randall, P. K., Meston, C. M., & Zvolensky, M. J. (2012). The association of smoking with testosterone in men. Nicotine & Tobacco Research, 14(7), 846–852.

World Health Organization. (2010). WHO laboratory manual for the examination and processing of human semen (5th ed.). Geneva: WHO Press.

Centers for Disease Control and Prevention (CDC). (2020). Health effects of cigarette smoking.