If you’ve heard someone say that “smokers have higher testosterone,” you’re not alone. You might be surprised to learn that this is actually supported by research. But like many viral health claims, the truth is more complicated.
Nicotine does not increase testosterone in any healthy or meaningful way. And in the long run, it’s far more likely to damage testosterone-producing cells, lower fertility and impair your sexual performance. Here’s why.
What does the science say about nicotine and testosterone?
Nicotine—whether from smoking, vaping, cigars, pouches, gum or patches—does not boost testosterone production.
A few large studies found that smokers sometimes have higher total testosterone. But what matters for libido, muscle strength, energy and sexual function is bioavailable testosterone—the portion your body can actually use.
One explanation is that nicotine appears to raise levels of sex hormone–binding globulin (SHBG). SHBG binds to testosterone, rendering it inactive. So if SHBG goes up, total testosterone might also rise, but your body can’t access it.
4 ways nicotine reduces testosterone production
When you look at higher-quality evidence, the picture becomes clearer: nicotine actively damages the cells and pathways your body uses to produce testosterone.
1. Nicotine harms testosterone-producing Leydig cells
Leydig cells in the testes are responsible for making testosterone. Laboratory studies show that nicotine and cotinine (a nicotine by-product) can reduce testosterone production in Leydig cells by 50 to 70%.
2. Nicotine disrupts hormone-signalling pathways
Nicotine has also been shown to trigger autophagy (self-destruction) of Leydig cells and interfere with an important hormone regulation pathway called TCL1–mTOR.
3. Nicotine reduces key testosterone-making enzymes
Chronic nicotine exposure also decreases the enzymes the testes need to produce testosterone, including StAR, 3β-HSD, CYP11A, steroidogenic factor-1. These enzymes are essential for converting cholesterol into testosterone.
4. Nicotine increases oxidative stress
Nicotine increases oxidative damage in testicular tissue, which lowers intratesticular testosterone, damages sperm development, and impairs overall reproductive health.
How nicotine impacts sexual performance and fertility
Smoking can seriously affect your sexual health and fertility. Nicotine narrows blood vessels and restricts blood flow to the penis, increasing the risk of erectile dysfunction. It also disrupts sleep, raises inflammation, and interferes with hormone production, making it harder to build and maintain muscle.
When it comes to fertility, nicotine can lower sperm count and motility, damage sperm DNA, disrupt LH and FSH signalling, and harm testicular tissue—all of which can make it more difficult to conceive.
Worried about your T levels?
To sum up, nicotine does not increase testosterone in any meaningful or healthy way. While a few studies show slightly higher total testosterone in smokers, this is misleading and does not reflect better hormone production or better hormonal health.
If you’re experiencing symptoms of low T, such as low libido and weight gain, nicotine won’t help. But there are evidence-based treatments that can meaningfully improve these symptoms, such as testosterone replacement therapy (TRT).
If you’re worried about your T levels, our at-home blood test can tell you whether you’d be suitable for TRT.
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