Cannabis and fertility: Why you should avoid cannabis products if you’re trying to conceive
What new research shows about THC and egg health – and why my advice to patients is clear
Cannabis use is growing rapidly in Australia. Women are using it for anxiety, for sleep, and increasingly to manage chronic pain conditions like endometriosis. But if you’re trying to conceive – naturally or through IVF – there’s new research you need to know about.
In September 2025, landmark research from the University of Toronto was published. It was the first study of its kind to examine what THC, the active compound in cannabis, actually does to human eggs. The findings were significant enough that I felt the need to be direct with patients about what they mean.
What the research found
The study analysed follicular fluid samples from more than 1,000 IVF patients. The researchers found that higher levels of THC were associated with eggs that matured faster but were less likely to be chromosomally normal.
Let me explain why that matters to you. Eggs with chromosomal abnormalities – meaning the genetic material is distributed incorrectly – are less likely to fertilise successfully. And if they do fertilise, the resulting embryos are more likely to either fail to implant in the uterus or result in miscarriage.
For women going through IVF, where egg quality is absolutely central to treatment success, this is a meaningful concern.
The exposure problem
What struck me most about this research was one critical finding: THC levels in the blood directly mirror those in the follicular fluid surrounding your eggs. This means all your eggs are being exposed to the same concentration of THC – not just some of them.
Think about what this means. If you’re using any cannabis product, every single egg in your ovaries is being exposed to the same level of that compound. If that level is high enough to affect chromosomal distribution, then your entire egg reserve is potentially affected.
This is different from other risks where only some eggs might be compromised. This is systemic exposure across all your eggs.
It applies to all cannabis products
This is important to emphasise: the potential risk applies across all cannabis products. That includes oils, edibles, cookies, teas, and medicinal cannabis prescribed for anxiety or pain management.
The active ingredient is THC in all of them. If a product contains THC – whether it’s recreational cannabis, medicinal cannabis prescribed by a doctor, or something you’ve bought from a dispensary – the potential risk to egg health is the same.
I know this may be a difficult message to hear, particularly if you’re using cannabis to manage anxiety or endometriosis pain. But the evidence is clear, and patients deserve to know what it shows.
Why this matters for your specific situation
If you’re trying to conceive naturally: THC exposure affects egg quality before fertilisation even occurs. Poor egg quality is one of the most common reasons couples struggle to conceive naturally. If you’re over 35, or if you’ve been trying for more than a year without conceiving, cannabis use is another factor actively working against your fertility.
If you’re doing IVF: Egg quality is everything in IVF. Treatment success depends on having eggs that are chromosomally normal and capable of fertilising. If you’re about to start an IVF cycle and using cannabis products, you’re potentially reducing the quality of the very thing you’re paying thousands of dollars to retrieve and fertilise.
If you’re using cannabis for endometriosis or anxiety: I understand why you’re using it. Endometriosis pain is real and severe. Anxiety is debilitating. Cannabis may be helping you manage symptoms. But if you’re planning to try for a baby – or even if you’re thinking you might want to eventually – the time to switch to alternatives is before you start trying, not after you’ve had difficulty conceiving.
What you should do
My advice, based on what the evidence shows, is clear: if you are trying to conceive naturally or through IVF, avoid cannabis products in any form.
If you are currently using medicinal cannabis to manage endometriosis or anxiety, I recommend you speak with your doctor about alternatives before you start trying to conceive. This isn’t about judgment. It’s about giving you the best possible chance of success.
If you’re already in an IVF cycle and using cannabis, stop immediately and let your specialist know. The sooner you stop exposure, the sooner your eggs can recover.
The bigger picture
The Canadian researchers who conducted this study were careful to note that their findings show an association between THC exposure and egg damage, not absolute proof of direct cause and effect. That’s the appropriate scientific caution. But association is what we work with in medicine. When we see a consistent association between a modifiable behaviour and a negative health outcome, we advise patients to modify that behaviour.
That’s what responsible medical practice looks like.
What to do if you need support
If you’re using cannabis to manage anxiety or pain, and you’re concerned about stopping, talk to your doctor. There are other options. Endometriosis pain can be managed through other medical treatments, physical therapy, and surgical interventions. Anxiety can be managed through psychological support, medication, and lifestyle approaches.
You don’t have to choose between managing your health and protecting your fertility. But you do need to have that conversation with your healthcare provider before you start trying for a baby.
If you’re planning to try for a pregnancy and currently using any cannabis products, I’d encourage you to book a consultation to discuss your situation. We can talk about your specific circumstances, answer your questions about this research, and help you plan a pathway that protects both your health and your fertility.