If you’ve been diagnosed with endometriosis, struggle with heavy periods, fibroids or experience symptoms linked to oestrogen dominance, you’ve probably wondered why your body seems to respond differently from someone else’s.
The answer isn’t always straightforward—but your genes may provide some valuable clues.
While your genetics don’t determine your future, they can influence how your body produces, metabolises and clears oestrogen, how efficiently it detoxifies environmental toxins, and how well it manages inflammation and oxidative stress. Together, these factors may increase your susceptibility to hormone-dependent conditions such as endometriosis.
Understanding these pathways is one of the reasons I incorporate a personalised, functional nutrition approach into my endometriosis support. By looking at your unique biology, we can create targeted nutrition and lifestyle strategies that work with your body rather than against it.
Can Genetics Cause Endometriosis?
There isn’t a single “endometriosis gene.” Instead, research suggests that multiple genetic variations may increase susceptibility when combined with environmental, hormonal and lifestyle factors.
This is why two women with similar lifestyles can have completely different hormonal experiences.
Your genes are one piece of a much larger puzzle.
Four Important Genes That Influence Oestrogen Metabolism
1. CYP19A1 (Aromatase) – The Oestrogen Production Gene
The CYP19A1 gene produces an enzyme called aromatase, which converts androgens into oestradiol, one of the body’s most potent forms of oestrogen.
Some genetic variants are associated with increased aromatase activity, meaning more oestrogen may be produced locally within tissues.
Higher aromatase activity has been linked with increased susceptibility to:
- Endometriosis
- Fibroids
- Oestrogen-sensitive symptoms
- Heavy or painful periods
While this doesn’t mean someone will develop these conditions, it may help explain why some women appear more sensitive to oestrogen than others.
2. CYP1B1 & CYP3A4 – How Your Body Processes Oestrogen
Producing oestrogen is only half the story.
Your body must also break it down into different metabolites, some of which are considered more favourable than others.
CYP1B1
This gene converts oestrogen into 4-hydroxy (4-OH) metabolites.
When this pathway becomes overactive, there may be increased production of reactive quinones, oxidative stress and cellular damage.
CYP3A4
This enzyme contributes to the production of 16α-hydroxy (16α-OH) metabolites.
Higher activity may be associated with:
- Increased oestrogen receptor stimulation
- Greater cell proliferation
- Enhanced oestrogen signalling
In contrast, metabolism through the 2-hydroxy (2-OH) pathway is generally considered the less proliferative route.
Supporting healthy oestrogen metabolism through nutrition and lifestyle is one of the ways we aim to optimise these pathways.
3. GST Genes – Your Detoxification Support System
The GST (Glutathione S-transferase) family of genes helps your body safely eliminate:
- Reactive oestrogen metabolites
- Environmental toxins
- Products of oxidative stress
Certain GST variants may reduce detoxification efficiency, potentially allowing harmful compounds to remain in the body for longer.
This doesn’t mean detox supplements are the answer. Instead, it highlights the importance of supporting your body’s natural detoxification systems through evidence-based nutrition, gut health and lifestyle interventions.
4. MTHFR C677T – Supporting Methylation
You’ve probably heard of the MTHFR gene, but it’s often misunderstood.
The MTHFR C677T variant may reduce the activity of an enzyme involved in methylation—a vital process required for numerous functions throughout the body, including hormone metabolism.
Reduced enzyme activity may contribute to:
- Less efficient methylation
- Reduced clearance of catechol oestrogens
- Increased oxidative stress, particularly if folate intake is inadequate
It’s important to remember that having an MTHFR variant doesn’t automatically mean you need supplements. Your overall diet, nutrient status and health picture matter far more than a single genetic result.
Genes Are Not Your Destiny
One of my favourite sayings is:
Genes load the gun. Lifestyle pulls the trigger.
Your genetic blueprint may increase susceptibility, but it does not determine your outcome.
The exciting part is that many of these pathways can be influenced through personalised nutrition and lifestyle medicine.
These include:
- Eating a fibre-rich diet to support healthy hormone elimination
- Including cruciferous vegetables to support oestrogen metabolism
- Maintaining a healthy body composition
- Regular movement and exercise
- Prioritising quality sleep
- Managing chronic stress
- Reducing exposure to environmental toxins where possible
- Supporting gut health and regular bowel movements
Small, consistent changes often have a far greater impact than chasing the latest supplement trend.
Should You Consider Nutrigenomic Testing?
Nutrigenomic testing can offer useful insights into how your body may process nutrients, hormones and toxins.
However, these genetic variants are not diagnostic. They cannot predict whether you will develop endometriosis or any other condition.
Instead, they provide another layer of information that can help personalise your nutrition and lifestyle plan alongside your symptoms, health history, blood tests and clinical assessment.
When interpreted correctly, genetic testing can help move away from generic advice and towards a strategy tailored to your unique biology.
Personalised Endometriosis Support
Living with endometriosis isn’t simply about managing symptoms—it’s about understanding the factors that may be driving them.
As a functional nutrition practitioner specialising in endometriosis and women’s hormonal health, I help women uncover the root contributors to their symptoms and develop practical, evidence-based strategies that support long-term wellbeing.
Whether you’re navigating a recent diagnosis, preparing for surgery, trying to optimise fertility or simply looking for answers after years of painful periods, personalised nutrition can play an important role in your care.
If you’d like to explore whether nutrigenomic testing could support your endometriosis journey, I’d be happy to discuss whether it’s appropriate for you as part of a comprehensive personalised plan.
Ready to take the next step? Get in touch to learn more about my endometriosis nutrition consultations and discover how a personalised approach could help you better understand your hormones and support your health.
