Where oestrogen is concerned, your body needs to use it and then swiftly lose it.
This is known as oestrogen clearance or oestrogen detoxification.
This blog is about the first two phases of oestrogen detoxification, which occur in your liver. In part 2 of this blog, I’ll explain the third and final phase of oestrogen clearance which occurs in the gut. In this blog, you’ll also learn how you can support your body with oestrogen clearance and in order to understand how certain foods, botanicals and nutrients can support you, you’ve got to know the basics of how you process oestrogen in your body once it’s been used.
Efficient clearance of used oestrogen is ESSENTIAL for hormone health because it prevents a build up of oestrogen in your system. A build-up of oestrogen in your body can increase PMS symptoms such as heavy and or painful periods, clotting, breast pain, headaches, mood swings as well as increase risk of fibroids, cysts and oestrogen-driven cancers.
To prevent oestrogen from spiking too high (and exacerbating all of the above) in the perimenopause oestrogen rollercoaster, you need to use it and LOSE it!
The need to efficiently clear our used oestrogen also applies to low oestrogen times such as the later part of perimenopause when oestrogen is declining and menopause when oestrogen is low and also if you are on hormone replacement therapy.
How your body clears out used oestrogen
Via an intricate process of breaking it down (metabolising it), which primarily happens in your liver, and then permanently excreting from the body via urine and bowel movements.
This detoxification process is occurring 24/7, it never takes a break and needs to be supported ALL the time.
In the liver, there are 2 main phases of oestrogen breakdown. Let’s look at each of these now.
Phase 1 Oestrogen Detoxification:
After oestrogen circulates throughout your body – doing all the “jobs” it needs to do, from keeping your hair shiny, your mood good and your menstrual cycles healthy to keeping your bones strong and supporting your metabolic health – it ends up in the liver, where it gets broken down into oestrogen “metabolites” (break-down products) and packaged-up for elimination and delivered to its final destination for just that – your intestines.
The breakdown (metabolism) and inactivation of your oestrogen occurs inside phase 1 of liver detoxification with the help of a group of enzymes. In this phase, used oestrogen goes through a chemical process called Hydroxylation, which converts it into 3 oestrogen metabolites; 2-Hydroxy-Oestrogen (2OH), 4-Hydroxy-Oestrogen (4OH), and 16-Hydroxy-Oestrogen (16OH).
You can think of 2OH as the well behaved, safe and preferred metabolite as 4OH as the unruly, not so safe or preferred metabolite and 16OH as somewhere in-between.
Your body will always distribute a certain percentage of oestrogen across all three pathways but the ideal scenario is that the majority of your used oestrogen is sent down the 2-OH pathway.
Some women can have genetic polymorphisms (the presence of two or more variations on a specific DNA sequence), which can impact the enzymes responsible for the breakdown of oestrogen down the various pathways. In this case, your body may need additional support in ensuring that the majority of your oestrogen gets broken down via the preferred (safest) pathway.
When too much of your oestrogen is processed down the 4-OH pathway it can be harmful for health and increase the risk of oestrogen-driven cancers. If too much is processed down the 16-OH pathway it can increase symptoms such as breast pain, heavy periods and fibroids.
I use the Dutch Complete Hormones Urine Test with myself and my clients to check hormone metabolism.

The above diagram, which is taken from the DUTCH test results, shows how the person is metabolising their sex hormones. It can indicate if / what oestrogen detoxification support is needed based on the ratio of the pathways oestrogen is being broken down via.
Support for Phase 1
The good news is that certain foods, botanicals and nutrients can support phase 1 detoxification and help it to work more efficiently.
The following foods support oestrogen metabolism and healthy breakdown pathways:
Cruciferous vegetables (broccoli, cauliflower, kale, cabbage, watercress, bok choy, Brussels sprouts) ECGC (the active compound in high quality green tea) Flaxseed Rosemary Oily fish (omega 3 fish oils EPA + DHA) Quality soy (edamame bean, organic tofu or tempeh) Curcumin (turmeric) Maca powder | Pure cocoa Yam Pomegranate Grapefruit and other citrus Berries (blueberries, strawberries, raspberries, blackberries) Colourful vegetables Parsley Peppermint Oil Red onion Beetroot |
Foods that can IMPAIR Phase 1 detoxification of oestrogen:
Inflammatory foods can impede proper oestrogen processing and prevent it from being broken down via the most favourable pathway and from achieving the most ideal split across all 3 pathways. Such as;
- Processed omega 6 oils, typically found in vegetable, rapeseed and sunflower cooking oils and sprays, margarines, processed foods, takeaways, deep-fried foods, confectionery and long-life baked goods.
- High consumption of sugar and processed/refined carbohydrates
- Burned/charred/blackened meats
- Alcohol
- Pesticides found on some non-organic fruits and vegetables (check the Pesticide Action Network UK website for a list of foods that should be bought organic wherever possible).
PHASE 2 OESTROGEN DETOXIFICATION:
In the second phase of oestrogen clearance, your liver takes your 2-OH and 4-OH (not 16-hydroxy) metabolites through a process called ‘methylation’ where it converts them into 2-methoxy-oestrogen, with the help of an enzyme called COMT (catechol-o-methyltransferase).
This process neutralises the metabolites, which makes them water soluble and now safe to leave the body in the bile, stool and urine.
Poor COMT enzyme activity can lead to a build-up of these “intermediary molecules” which can be harmful to the body and hormone health.
This process relies on the function of the COMT enzyme so we want to support this enzyme to work properly. Some people can have genetic variations on this enzyme that can slow this enzyme down, making it work less efficiently and more sluggishly.
For the efficient and safe clearance of used oestrogen from the body both phases 1 and 2 must be working well.
Support for Phase 2
The good news is that certain ‘cofactor’ nutrients can support the COMT enzyme to work better, such as;
- Magnesium
- B Vitamins, particularly B12, B6 and folate (B9)
- Choline
- N-Acetyl-Cysteine (NAC) which comes from the amino acid (found in protein) L-cysteine
- Trimethylglycine or TMG (also referred to as betaine)
Chronic stress and inflammation can impair the COMT enzyme.
Where things can go wrong
Anything that impacts your liver’s ability to efficiently process and clear out your used oestrogen is going to be a factor in symptoms and conditions associated with hormone imbalances, especially heavy and or painful periods, clotting, breast pain, headaches, mood swings and increased risk of fibroids, cysts and oestrogen-driven cancers.
An overloaded liver – if other toxins are high your liver will be overburdened and therefore not able to efficiently keep up with oestrogen detox. The detoxification of alcohol, also a toxin, is prioritised over oestrogen detox so if alcohol use is high and or frequent this impacts oestrogen detox.
Factors that contribute to liver overload:
Environmental toxins and chemicals – Certain chemicals (also known as xenoestrogens) from things such as plastics, pesticides, skin and hair care products, fragrances, sprays, makeup and household cleaning products and detergents mimic real oestrogen once inside the body, entering the cell and increasing your total load of oestrogen and increasing the detoxification burden on your liver.
Alcohol – Alcohol must be detoxified as soon as it reaches your liver and this will always take precedence over the detoxification of other toxins and used hormones. Acute consumption of alcohol has been shown to increase oestrogen levels in the body.
In Part 2 of this blog you will learn about the third and final phase of used oestrogen clearance, which occurs in the gut. This is sometimes the first place to start for people because even though it’s the ‘third phase’, if it’s not working properly, the oestrogen processed in phases 1 and 2 risks being reabsorbed back into the body and into circulation. It’s important to understand all 3 phases and then you can better understand which phases you may need to start supporting first.