Nicotine pouches — also known as “snus” and “ziz” from brands like Zyn and Velo — are small bags containing tobacco or nicotine and sometimes sweeteners and flavours. They’re put between the lip and gum, and the nicotine is absorbed into the bloodstream. A 2024 survey of Australians aged 16-39 found that 26% had ever used them and 19% had used them in the past 30 days. Some users think they’re a healthier alternative to smoking and vaping, and others claim they help enhance athletic performance. While there’s no long-term research on the health impacts of nicotine pouches, there is plenty we know about the health impacts of nicotine and why these pouches are far from harmless.
What is nicotine and how does it work?
Nicotine is a naturally occurring chemical found in tobacco plants. It’s the main addictive substance in cigarettes, vapes and other tobacco or nicotine products. It’s what drives people to continue their use despite knowing the health risks and wanting to stop. Nicotine’s addictive effect is caused by changes it makes to the brain, but it also has other harmful effects throughout the body.
Nicotine acts in the body by binding to specific receptors, mainly on nerve and muscle cells, with an effect like activation of the body’s ‘fight-or-flight’ response (stimulation of the sympathetic nervous system).
Short-term effects of nicotine
In the brain, the short-term effect of nicotine is to increase attention and alertness. In muscles, the acute effect of nicotine is to briefly enhance contraction. In the cardiovascular system, the acute effect of nicotine is to increase heart rate and blood pressure. These effects all result from only small amounts of nicotine. In higher doses, nicotine can cause seizures, heart palpitations, and muscle twitches or tremors. Other acute effects of nicotine include nausea and vomiting, headache, dizziness, sweating and agitation. High doses of nicotine can be fatal. Nicotine affects sexual function, as shown by a study that found an intermediate dose of isolated nicotine significantly reduces erectile response in healthy, young, nonsmoking men.
Nicotine tolerance, addiction and changes in the brain
Tolerance to nicotine develops quickly, so higher amounts are needed to achieve the short-term ‘buzz’. This effect is driven by changes in the types, numbers and cellular locations of nicotine receptors in the brain. Nicotine also hijacks the brain’s reward system to cause addiction.
Animal experiments demonstrate that brain development is affected by nicotine and that associations in humans between tobacco use and “deficits in cognition, attention, sensory processing, and neuropsychiatric disorders is due to exposure to nicotine”. These changes in the brain, caused by nicotine, may explain why people who use tobacco have higher-than-normal rates of depression, anxiety, schizophrenia and ADHD.
Long-term effects of nicotine
The health effects of smoking are well established, but how much these effects are due to nicotine is less well known. The rise in popularity of vapes, lozenges and oral nicotine pouches, especially in young males, means that understanding the health effects of nicotine itself, separate from smoking, is becoming more important.
Effects of nicotine on sexual function and fertility
Vaping seems to result in long-term activation of the sympathetic nervous system and increased inflammation, which increases the risk of cardiovascular disease. Cardiovascular health is critically important for erectile function, so (together with the short term effects of nicotine described above) vapes, pouches and other sources of nicotine spell bad news for sexual function in both the short- and long-term.
Associations between low libido (low sex drive) and smoking may be, at least in part, due to nicotine’s effects on mood – since depression and anxiety are both independently associated with low libido – but there is no direct evidence to support or refute this possibility.
Nicotine has negative effects on sperm function in experimental animals and use of oral tobacco pouches lowers sperm count in humans, consistent with the established negative effects of tobacco smoking on semen quality and fertility.
What to do about nicotine use
It took decades between the first concerns about tobacco smoking’s effects on health and definitive proof of it causing cardiovascular disease and lung cancer. Widespread use of nicotine through vaping and oral pouches is only a recent phenomenon, so we’re just beginning to examine the effects on health and wellbeing. What we already know about nicotine’s effects in the brain is cause for enough concern to avoid nicotine altogether.
Tim Moss
Healthy Male Health Content Manager
Dr Tim Moss has PhD in physiology and more than 20 years’ experience as a biomedical research scientist. Tim stepped away from his successful academic career at the end of 2019, to apply his skills in turning complicated scientific and medical knowledge into information that all people can use to improve their health and wellbeing. Tim has written for crikey.com and Scientific American’s Observations blog, which is far more interesting than his authorship of over 150 academic publications. He has studied science communication at the Alan Alda Centre for Communicating Science in New York, and at the Department of Biological Engineering Communication Lab at MIT in Boston.
