Testosterone and Smoking: The Contradictory Evidence Explained
The relationship between smoking and testosterone is one of the more confusing topics in men's health research. Unlike most lifestyle factors, where the direction of effect is fairly clear, smoking presents what looks like a paradox: some studies find that smokers have higher total testosterone than nonsmokers. Some corners of the internet treat that as evidence that smoking helps male hormones. The fuller picture is more complicated and much less favorable to smoking.
Key takeaways
- A meta-analysis of 22 studies in 13,317 men found smokers had higher mean total testosterone than non-smokers (by 1.53 nmol/L).[1]
- In the European Male Aging Study, smoking was linked to higher SHBG and total testosterone but not higher free testosterone.[2] In a study of 6,296 Chinese men aged 40 to 79, smokers and ex-smokers reported more symptoms of late-onset hypogonadism than non-smokers.[3]
- Smoking is associated with lower sperm count (about 10 million per mL lower) and motility,[4] and 10 more cigarettes a day was associated with 14 percent higher odds of erectile dysfunction.[5]
- Quitting improves semen quality within 3 to 6 months in a small study,[6] though testosterone changes after quitting are inconsistent.[7,8]
The Paradox: Why Smokers Can Show Higher Total Testosterone
A 2016 systematic review and meta-analysis found that in 22 studies of 13,317 men (mean ages 18 to 61), smokers had a higher mean testosterone than non-smokers (1.53 nmol/L, 95% CI 1.11 to 1.96). In women the association was not clear.[1] Part of the explanation may be binding protein: total testosterone includes the large share carried by sex hormone-binding globulin (SHBG). In the European Male Aging Study (3,200 men aged 40 to 79), smoking was associated with higher SHBG (+5.96 nmol/L) and higher total testosterone (+1.31 nmol/L), but not with free testosterone, which the authors interpreted as a resetting of the testosterone-LH feedback loop due to elevated SHBG.[2]
The Explanation Is Not Settled
SHBG is one proposed explanation. Another hypothesis, noted by the authors of the meta-analysis, is that cotinine, a tobacco metabolite, inhibits testosterone breakdown.[1] The picture is also not uniform across ages: in a study of 6,296 men aged 40 to 79, total testosterone was higher in smokers in all but the 70 to 79 group, free testosterone was higher in smokers aged 40 to 59 but not 60 to 79, and sexual and somatic symptom scores were higher in current and ex-smokers than in non-smokers in every age group.[3] In other words, a higher blood number did not translate into fewer symptoms.
What Smoking Does to Sexual and Reproductive Health
Whatever the testosterone numbers show, other outcomes tied to male sexual health point in the wrong direction for smokers:
✓ What Studies Found on Testosterone
- •Smokers average higher total testosterone in observational studies
- •Free testosterone differences are inconsistent across studies
✗ What Studies Found on Health Outcomes
- •Lower sperm count and motility in smokers
- •Higher odds of erectile dysfunction with more cigarettes per day
- •More late-onset hypogonadism symptoms in smokers and ex-smokers in one large study
A meta-analysis of 20 studies (5,865 men) found cigarette smoking was associated with reduced sperm count (mean difference -9.72 million per mL), motility (-3.48 percent) and morphology (-1.37 percent), with larger effects in moderate and heavy smokers.[4] A dose-response meta-analysis of 10 observational studies (50,360 participants) found the odds of erectile dysfunction rose 14 percent for every extra 10 cigarettes smoked per day, and 15 percent for every additional 10 years of smoking.[5] Sexual function also depends on blood vessels, not only on hormones; see our article on testosterone and libido.
Vaping and Nicotine Replacement: Unknown
The authors of the smoking-testosterone meta-analysis explicitly noted that whether products that raise cotinine, such as e-cigarettes or nicotine replacement, also raise testosterone has not been investigated.[1] We could not find human studies measuring testosterone in people who vape, so we cannot say whether vaping helps, hurts or has no effect on testosterone, and we do not rely on laboratory-model findings to claim either. Nicotine is addictive in any form. If you want to quit, a doctor or pharmacist can help with evidence-based options. For another commonly used substance, see our review of whether weed lowers testosterone.
Chronic stress can also affect hormones; see cortisol and testosterone.
Quitting: What the Studies Show
What Research Shows After Smoking Cessation
Semen parameters improve
In a study of 60 men in a cessation program, semen volume, sperm concentration, total sperm count and motility improved significantly at 3 and 6 months after quitting, with a time-dependent effect.
SHBG falls; total testosterone change is small
In a study that followed men who quit smoking, SHBG decreased significantly after one year without smoking, while the decrease in total testosterone was not statistically significant.
Population data are mixed
In the longitudinal European Male Aging Study, smoking cessation was associated with a greater decline in testosterone than being a non-smoker, which was unrelated to weight change. The authors did not interpret this as a reason to keep smoking, and the reason is unclear.
If you track your lab values, be aware that SHBG and total testosterone can shift after quitting, so interpret any change with your doctor rather than on its own. Quitting is widely advised for heart, lung and sexual health whatever happens to a single testosterone number.
The Bottom Line
Yes, studies find that smokers on average have slightly higher total testosterone. No, that does not make smoking good for your hormones or your sexual health. The increase is not matched by a clear gain in free testosterone or by fewer symptoms, and smoking is associated with poorer sperm quality and higher odds of erectile dysfunction. If you are serious about supporting testosterone naturally, quitting smoking (or never starting) aligns with that goal. Put your energy into factors with clearer benefits: sleep, training, nutrition and daily habit consistency. If you have symptoms such as low libido or persistent fatigue, see a doctor.
Related Reading
- The Complete T-Maxing Guide: the habit stack for building healthy routines.
- Signs of Low Testosterone: symptoms worth discussing with a doctor.
How Thrive Helps
Thrive is a wellness app that helps you track the lifestyle factors that support healthy routines, with evidence grades that cut through confusing claims. Build consistent daily habits around sleep, exercise, nutrition and stress management, and see how they compound over time. Thrive is not a medical device and does not diagnose or treat any condition. Try Thrive free on the App Store.
References
- Zhao J, Leung JYY, Lin SL, Schooling CM. Cigarette smoking and testosterone in men and women: a systematic review and meta-analysis of observational studies. Prev Med. 2016. doi.org/10.1016/j.ypmed.2015.12.021
- Wu FC, Tajar A, Pye SR, et al.. Hypothalamic-pituitary-testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging Study. J Clin Endocrinol Metab. 2008. doi.org/10.1210/jc.2007-1972
- Liu Q, Peng X, Gu Y, et al.. Associations between smoking, sex hormone levels and late-onset hypogonadism in men differ depending on age. Aging (Albany NY). 2021. doi.org/10.18632/aging.202442
- Sharma R, Harlev A, Agarwal A, Esteves SC. Cigarette smoking and semen quality: a new meta-analysis examining the effect of the 2010 World Health Organization laboratory methods for the examination of human semen. Eur Urol. 2016. doi.org/10.1016/j.eururo.2016.04.010
- Cao S, Gan Y, Dong X, Liu J, Lu Z. Association of quantity and duration of smoking with erectile dysfunction: a dose-response meta-analysis. J Sex Med. 2014. doi.org/10.1111/jsm.12641
- Ragheb A, Abdelbary A, Massoud A, Abd Elkhalek M, Elbatanony A. Evaluating the effect of smoking and its cessation on semen parameters. Reprod Fertil. 2025. doi.org/10.1530/RAF-24-0135
- Hruskovicova H, Duskova M, Simunkova K, et al.. Effects of smoking cessation on hormonal levels in men. Physiol Res. 2013. doi.org/10.33549/physiolres.932326
- Camacho EM, Huhtaniemi IT, O'Neill TW, et al.. Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study. Eur J Endocrinol. 2013. doi.org/10.1530/EJE-12-0890