Vaping is often presented as the “healthier” alternative to smoking.
And in some ways, that is probably true.
If someone is trying to stop smoking cigarettes, vaping may reduce exposure to some of the most harmful chemicals found in tobacco smoke. It does not contain tar or carbon monoxide, and public health guidance generally views vaping as less harmful than smoking.
But fertility is a different conversation.
When we are talking about sperm health, IVF outcomes, miscarriage risk and the quality of DNA being passed on to a future child, “less harmful than smoking” is not the same thing as “safe”.
And this is where I think vaping has been given far too easy a ride.
Vaping is new. Sperm biology is not.
One of the problems with vaping is that it is still relatively new.
Male fertility research is not quick. To properly understand the effect of an exposure on sperm, pregnancy outcomes and potentially offspring health, you need long-term data. You need to follow people over time. You need to look not just at whether conception happens, but what happens afterwards.
Does fertilisation occur?
Does the embryo develop normally?
Does implantation happen?
Is there a miscarriage?
Is the baby healthy?
That kind of research takes years.
So when people say “there isn’t enough evidence that vaping harms fertility”, I think we need to be very careful. Lack of long-term evidence is not the same as evidence of safety.
Especially when we already know that vapes contain substances that are biologically plausible causes of harm to sperm.
What do we know so far?
The research is still developing, but what we have so far is enough to raise concern.
A Danish study of young men found that daily e-cigarette users had significantly lower total sperm counts than non-users. This does not prove vaping was the cause - the study was observational - but it is not reassuring.
Other research has found that vape aerosols can contain toxic metals including nickel, lead, arsenic and manganese. Some of these metals are known reproductive toxins. They can contribute to oxidative stress, inflammation and cellular damage.
And when we are talking about sperm, oxidative stress matters.
Sperm are particularly vulnerable to oxidative damage because they have very little internal repair capacity. Once sperm DNA is damaged, the body has limited ability to fix that before fertilisation.
This is one of the reasons I am so interested in sperm DNA fragmentation testing. Standard semen analysis looks at count, motility and morphology. It does not assess whether the DNA inside the sperm is intact.
So a man can have a “normal” semen analysis and still have high sperm DNA fragmentation.
“But vaping is better than smoking”
This is the bit that gets confusing.
For general public health, vaping may be less harmful than smoking cigarettes. That is the argument often made in smoking cessation guidance.
But from a fertility perspective, that is not really the right question.
The question is not:
“Is vaping better than smoking?”
The question is:
“Is vaping compatible with optimal sperm health before conception?”
And based on what we know about nicotine, heavy metals, oxidative stress and sperm DNA damage, I would not be comfortable saying yes.
A recent IVF study suggested that men who vaped had better outcomes than men who smoked cigarettes. That may sound reassuring at first glance. But the study compared vaping with smoking. It did not compare vaping with not smoking or not vaping.
That distinction matters.
Being less harmful than cigarettes does not make vaping fertility-safe. It just means cigarettes are worse.
Nicotine itself is a problem
It is also important not to focus only on the vape device or the flavourings.
Nicotine itself may affect sperm.
Research has linked nicotine exposure with poorer sperm motility, viability and morphology, as well as increased oxidative stress. Nicotine may also affect testosterone, testicular function and the hormonal environment involved in sperm production.
So even if a vape contains fewer tobacco-related toxins than cigarettes, the nicotine exposure itself may still be relevant.
And many people who vape are not using tiny amounts of nicotine. Some are using vapes frequently throughout the day, often without the same sense of “how much” they would have had with cigarettes.
That makes it very difficult to quantify exposure.
Heavy metals and sperm DNA
One of the most concerning aspects of vaping is the presence of heavy metals in some vape aerosols.
These can come from the heating coil and other metal components inside the device. When the liquid is heated and inhaled, tiny particles can be released.
Why does this matter for fertility?
Because heavy metals are associated with oxidative stress, endocrine disruption and damage to reproductive cells. Sperm are especially vulnerable because they are small, highly specialised cells carrying tightly packed DNA.
This is not just about whether sperm can swim.
It is about whether the DNA inside the sperm is structurally intact.
Sperm DNA fragmentation has been associated with poorer IVF outcomes, lower embryo quality, recurrent miscarriage and longer time to pregnancy. Yet it is still not routinely tested in many fertility pathways.
This is one of the frustrating gaps in fertility care. We often look at the female partner in enormous detail while relying on a basic semen analysis for the male partner, even when there are clear reasons to look deeper.
Vaping before IVF
If a couple is preparing for IVF, I would not view vaping as harmless.
IVF does not bypass sperm health. Even with ICSI, where a single sperm is injected directly into an egg, sperm DNA still matters. The embryologist can select a sperm that looks reasonable under the microscope, but they cannot see whether the DNA inside that sperm is damaged.
This is why I often recommend that sperm health is assessed and optimised before treatment begins, especially where there has been:
- poor embryo development
- failed IVF
- miscarriage
- unexplained infertility
- male factor infertility
- high oxidative stress
- smoking or vaping exposure
- varicocele
- recurrent infection or inflammation
Sperm take roughly three months to develop. That means the three months before IVF are not a waiting room. They are a treatment window.
What happens during that period may influence the quality of sperm available at egg collection.
What about second-hand vaping?
The evidence on second-hand vaping and fertility is still limited.
But again, I would apply the precautionary principle.
If vape aerosols can contain nicotine, volatile chemicals and metal particles, I would not want regular exposure around someone trying to conceive, undergoing IVF or in early pregnancy.
We already know that second-hand cigarette smoke is associated with poorer reproductive outcomes. We do not yet have the same long-term evidence for second-hand vaping, but that does not mean it should be assumed safe.
Especially around pregnancy, “we don’t know yet” should not be treated as reassurance.
So should men stop vaping when trying to conceive?
In my view, yes.
If a man is vaping and trying to conceive, preparing for IVF, or there has been miscarriage or poor embryo development, I would want vaping stopped if at all possible.
Not because we can prove exactly how much harm every vape causes.
But because we know enough about the ingredients, mechanisms and early research to say this is unlikely to be helping.
The aim before conception is not simply to avoid the worst possible exposure.
The aim is to create the best possible environment for sperm production, DNA integrity and embryo development.
For some men, stopping vaping may be part of a wider sperm health plan, alongside nutrition, antioxidant support, reducing heat exposure, treating infection or inflammation, assessing varicocele, and considering sperm DNA fragmentation testing.
The bottom line
Vaping may be less harmful than smoking for general health.
But fertility is a more sensitive question.
Sperm are vulnerable to oxidative stress, nicotine, heavy metals and environmental chemicals. Vaping exposes the body to several of these, and long-term fertility data is still limited.
So my position is simple:
If you are trying to conceive, preparing for IVF, or trying to reduce miscarriage risk, vaping should not be treated as harmless.
It may be better than smoking.
But better than smoking is not the same as good for sperm.
Further Reading & Resources
If you're concerned about sperm health, recurrent miscarriage, failed IVF cycles or the potential impact of lifestyle factors such as vaping, the following resources may be helpful:
Sperm DNA Fragmentation Testing
A standard semen analysis looks at sperm count, motility and morphology, but it does not assess whether the DNA inside the sperm is intact. Learn more about sperm DNA fragmentation testing and when it may be worth considering.
Male Fertility Support
Explore the common causes of male infertility, the tests available, and the steps that may help improve sperm quality before conception or IVF.
Support to Stop Smoking or Vaping
Quitting nicotine can be challenging, particularly during the stress of fertility treatment. If you're struggling to stop smoking or vaping, hypnotherapy may help address cravings, habits and behavioural triggers. Our clinical network offers fertility-focused hypnotherapy support.
Epigenetics & DNA Fragmentation
Sperm contribute far more than just half of a baby's DNA. Learn how sperm health may influence embryo development and long-term offspring health.
Epigenetics & DNA Fragmentation article
Can You Predict Your Fertility?
An exploration of declining fertility rates, environmental exposures and the factors that may be influencing reproductive health in both men and women.
Can You Predict Your Fertility article
Concerned About Your Fertility?
If you're trying to conceive, preparing for IVF, or have experienced miscarriage, our fertility assessment process is designed to identify potential gaps in testing and help you understand whether further investigations may be worthwhile.
References
- Holmboe SA, Priskorn L, Jørgensen N, Skakkebæk NE, Linneberg A, Juul A, Andersson AM. Use of e-cigarettes associated with lower sperm counts in a cross-sectional study of young men from the general population. Human Reproduction. 2020;35(7):1693–1701.
- National Health Service (NHS). Vaping: Myths and Facts. Available at: https://www.nhs.uk/better-health/quit-smoking/ready-to-quit-smoking/vaping-to-quit-smoking/vaping-myths-and-the-facts/
- Centers for Disease Control and Prevention (CDC). Health Effects of Vaping. Available at: https://www.cdc.gov/tobacco/e-cigarettes/
- Budin SB, Othman F, Louis SR, et al. The effects of nicotine on sperm parameters and oxidative stress in reproductive tissues. Journal of Applied Toxicology. 2017.
- Erat M, Ciftci M, Gumustekin K, et al. The effect of nicotine on reproductive function and oxidative stress.Reproductive Toxicology. 2007.
- U.S. Food and Drug Administration (FDA). Potential Health Risks Associated with Electronic Cigarettes. Available at: https://www.fda.gov/tobacco-products
- Zhao S, Niu X, Xu Y, et al. Electronic cigarette exposure, oxidative stress and male reproductive health: a review of current evidence. Frontiers in Endocrinology. 2024.
- Shanna H. Swan. Countdown: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperilling the Future of the Human Race. Scribner; 2020.
- Agarwal A, Baskaran S, Parekh N, et al. Male infertility and oxidative stress: a comprehensive review. World Journal of Men's Health. 2019;37(3):296–312.
- Esteves SC, Zini A, Coward RM, et al. Sperm DNA fragmentation testing: summary evidence and clinical practice recommendations. Andrologia. 2021;53(2).
- World Health Organization. WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th Edition. Geneva: World Health Organization; 2021.
- Practice Committee of the American Society for Reproductive Medicine. The clinical utility of sperm DNA integrity testing: a guideline. Fertility and Sterility. 2020.
- Tattan-Birch H, Jackson SE, Kock L, et al. Association of electronic cigarette use with health outcomes: emerging evidence and ongoing uncertainties. Tobacco Control. 2024.
- National Academies of Sciences, Engineering, and Medicine. Public Health Consequences of E-Cigarettes.Washington, DC: The National Academies Press; 2018.
- Sokol RZ, Kraft P, Fowler IM, et al. Exposure to environmental toxins and male reproductive health. Fertility and Sterility. Various reviews and consensus statements.
Disclaimer
Research into vaping and fertility is still evolving. Whilst the evidence base is growing, long-term studies examining the effects of vaping on conception, miscarriage, IVF outcomes and offspring health remain limited. The absence of long-term data should not be interpreted as evidence of safety, particularly where exposure involves substances already known to affect sperm function, oxidative stress and DNA integrity.