18 Natural Aromatase Inhibitors

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18 Natural Aromatase Inhibitors

The number one topic in breast cancer communities, and the thing I get asked about most often, is definitely about natural aromatase inhibitors.  People are suffering from the effects of hormone inhibiting drugs – the list of side effects these drugs are capable of producing is seemingly endless. As a breast cancer coach, I hear all about them and have a great deal of sympathy for those taking these drugs.

It’s a subject near and dear to our hearts and we can spend plenty of time trying to dig up research on new natural alternatives – I know I do because I chose not to take Tamoxifen, much to my oncologist’s annoyance.  I just wasn’t willing to risk the side effects, such as cardiotoxicity and blood clots, etc. 

Update: I recently wrote an article sharing why I chose not to take Tamoxifen, in case you’re interested: Why I Chose Against Hormone Blocking Drugs

It worries me that the side effects of these drugs can be so debilitating and disruptive to quality of life.  More than that, I know quite a few who were on AIs for the requisite period of time (usually 5 years) and suffered recurrences anyway.  That indicates to me these drugs aren’t working as well as they are meant to.

A Good Article

While doing some research recently, I came across a lengthy article, on the NIH website,  “Natural Products as Aromatase Inhibitors” [1]. Be warned, that article will do your head in, unless you are a doctor, researcher or medical professional! 

I will attempt to boil it all down into layman’s language for you – you can read for yourself all of the reasons why AIs are prescribed, how they work in breast cancer, and how scientists are actively researching many natural products to discover which ones can be utilized to help breast cancer patients.  I know what you are really after — the list of natural things that exhibit AI activity. 

18 Natural Aromatase Inhibitors

  1. Dioon Spinulosum – or gum palm, a cycad which grows in Veracruz and Oaxaca, Mexico
  2. Encephalartos ferox – also a cycad which grows mainly in Africa
  3. Riedelia – a genus of plants in the Zingiberaceae family, comprises approximately 75 species that are distributed among New Guinea and the Maluku and Solomon Islands
  4. Viscum album – a species of mistletoe, also known as European Mistletoe or Common Mistletoe to distinguish it from other related species. It is native to Europe and western and southern Asia
  5. Cycas rumphii – also a cycad, commonly known as queen sago or the queen sago palm, it grows in the Moluccan island group (New Guinea, Java, Indonesia)
  6. Cycas revoluta – also a cycad, native to southern Japan
  7. Alpinia purpurata – also known as Red Ginger, a native to Malaysia
  8. Coccothrinax Sarg – Coccothrinax is a genus of palms in the Arecaceae family, there are more than 50 species described in the genus, plus many synonyms and sub-species, and they grow in a variety of places
  9. Five red wine varieties, the most active being Cabernet Sauvignon from Tanglewood (France), the other mentioned was Pinot noir from Hacienda (Sonoma, CA)
  10. Brassaiopsis glomerulata – a deciduous tree found in North Vietnam
  11. Garcinia mangostana L. (Clusiaceae) – also known as mangosteen, has a long history of use as a medical plant, found mostly in Southeast Asia
  12. Euonymus alatus – also known as winged spindle, winged euonymus or burning bush, it’s a species of flowering plant in the family Celastraceae, native to central and northern China, Japan, and Korea
  13. Isodon excisus Kudo var. coreanus – a small herbaceous plant that grows in Western Asia (Japan, China, Korea)
  14. Scutellaria barbata – a plant used in traditional Chinese medicine, other names include ban zhi lian’, scullcap or skullcap, it grows in Korea and southern China
  15. Camellia sinensis – also known as green tea (easily obtainable every morning for breakfast!)
  16. Vitis L. sp – also known as grape seed extract, the report cited a study where a water extract of grape seed extract was utilized and it had AI activity
  17. Agaricus bisporus – also known as white button mushrooms
  18. Trifolium pratense L. – also known as red clover flowers.  There is a lot of misinformation out there about red clover, please read my article Red Clover Controversy – Safe For Breast Cancer Or Not?

Update: See two more discussed below – selenium and pomegranate.

The article also mentioned that coffee, cocoa, collards, stout beer, tomato leaves and even cigarette smoke (!) strongly inhibited aromatase using a microsomal assay.  I don’t know about you but I’m not eating tomato leaves or breathing in cigarette smoke intentionally!

Many of the above listed things are not currently being produced as natural supplements.  I would suggest you print out this list and take it to your naturopath to see which ones would be available and safe for you to use.  Some of the listed items will be easily available (like #9, #15, #16, #17 #18) and you could easily incorporate them into your diet. 

Something not listed is selenium, we do have research indicating that it acts as a natural aromatase inhibitor, see my article  Why Iodine and Selenium Are Useful For Breast Cancer.

2017 Update – I found an older study from 2010 [2] indicating that the ellagitannins (phytochemicals) in pomegranates also had anti-aromatase activity. So make that 20 natural aromatase inhibitors (including selenium, above).

The above list is not exhaustive – the report did also discuss 125 flavonoids, 36 terpenoids, 19 peptides, 18 lignans, 16 xanthones, 15 fatty acids, 10 alkaloids, and 43 miscellaneous compounds having been evaluated but there was not sufficient information for me to feel it was worth listing them all.

Unfortunately, there is no information on dosages for any of the above nutrients, more information is clearly needed.

Just Remember Estrogen Is Not The Only Factor Involved In Breast Cancer

The important thing I would like you to take away from all of this is that we can drive ourselves crazy looking for the tiniest things that will give us an edge over this disease.  I hope you don’t get bogged down in this. Please remember, estrogen is not the only factor involved in breast cancer.  An overall anti-cancer strategy is to eat a healthy diet full of  fresh organic fruits and vegetables and super foods,  take the supplements that have research backing them (see my page discussing that topic), limit your exposure to toxic skin care products, get plenty of exercise DAILY and keep your stress levels down through the use of meditation or prayer. 

You may want to read some of my other articles about aromatase inhibitors:

The Down & Dirty on Aromatase Inhibitors for Breast Cancer Treatment

Acupuncture: How It Helps With Cancer Treatments

Aromatase Inhbitors Natural vs Toxic

Researchers Discover Mushrooms Could Be Potent Natural Aromatase Inhibitors

Why Vitamin D is So Important for Breast Health

Is Chrysin a Good Natural Aromatase Inhibitor?


[1] Natural Products as Aromatase Inhibitors — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074486/

[2] Pomegranate ellagitannin-derived compounds exhibit antiproliferative and antiaromatase activity in breast cancer cells in vitro – https://www.ncbi.nlm.nih.gov/pubmed/20051378

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27 thoughts on “18 Natural Aromatase Inhibitors

    1. Hi Barb,
      Thanks for your comment. You are right, broccoli is a cancer inhibitor – slightly different to being an aromatase inhibitor – aromatase is the enzyme that converts the adrenal hormones androstenedione and estrone to estrogen. Inhibiting its action is one approach to breast cancer prevention and treatment. For other cancer inhibitors, see my page “Diet and Cancer”.

    1. Hi Catherine,
      You are more than welcome. Just please realize that healing from breast cancer is WAY more than just inhibiting estrogen and aromatase, that’s just the tip of the iceberg. I hope you have signed up for my free newsletters and e-books? I share lots more information in them and you can ask questions and get answers.
      Warmest regards,
      Marnie Clark

  1. I was diagnosed with estrogen receptive breast this year. I’m having trouble taking the AI pills. Lots of back, low back and side pain. In physical therapy and taking pain pills. I’m just trying to learn all I can about these pills. I find your website very informative. I just signed up for your ebook, but I don’t see where I can download it. Thank you for all your information.

    1. Hi Pat,
      Thanks for your comment, I can definitely sympathize. I just sent you an email response, so be on the lookout for that.
      Warmest regards,
      Marnie Clark

  2. Thank you for the Information. I am scheduled to begin my AI treatment and I am more afraid if this than a reoccurence! Any suggestions.

    1. Hi Jo,
      Thanks for your comment and I apologize for the late reply. I have just sent you some information by email.
      Warmest regards,

  3. I quit taking arimidex 5 weeks ago after being on it only a year. I already have osteoporosis which the doctor responded by trying to push a bone drug on me and I said no. Gradually I had more and more joint pain. The last straw was when I realized that I still had wimpy looking clown hair that wasn’t growing properly 18 months out from chemo due to this drug converting androgens into testosterone! Intuitively I know I did the right thing because the side effects have disappeared

  4. I am trying to manage age-related prostate hypertrophhy with aromatase inhibitors. Estrogen stimulates growth of prostate stromal cells and is believed to be a significant factor in this hypertrophy. The idea here was to raise the ratio of testosterone to estrogen, and by symptoms it totally worked. Three cheers!
    But. I’ve been on 60 mg of resveratrol for about 2 months. This has raised my resting blood pressure from 120/70 to 130/80 (not a particularly big deal, but why?) and my TSH levels from 0.5-1.5 normal to 2.7 (more bothersome, nominally still normal, but why ?). Looking into this, I have found published data showing that a) resveratrol inhibits uptake of iodide into the thyroid and b) that aromatase (CYP19A1) is found in vascular smooth muscle cells and (estrogen) probably is a factor in bloop pressure. Various blood pressure conditions have been associated with CYP19A1 gene polymorphisms.
    This is just a caution about chronic use of resveratrol or ANY bioactive substance. There are always side effects whether natural or pharmaceutical, and I do believe that the range and severity of problems with natural is likely to be smaller. I am going to try using a rotation of items from this excellent list of aromatase inhibitors as a strategy to minimize side effects (may be folly on the blood pressure side). May try dose reduction on resveratrol also.

  5. After only 3 doses of AI I am ready to quit. I have massive nausea. I have young children and cannot be a good mom when i feel so rotten. I don’t want to take anymore! Chemo was easier to take than years on this drug.

    1. LaDawnna,
      You are definitely not the only one to feel this way. I chose not to take any hormone blocking meds, indeed I chose a completely different path. I talk about some of the things I did instead in this article: http://marnieclark.com/searching-for-tamoxifen-alternatives/ . Check it out. You don’t actually have to be on these drugs but you will need to be very proactive and do other things instead. Have you signed up for my free newsletters and e-books? They are full of my best information on healing from breast cancer and avoiding recurrences and I have just updated them with the latest info and research. You can sign up from any page on my site, if you haven’t already done so.
      Warmest regards,
      Marnie Clark

      1. Hello Marie,

        I cannot find a way of joining your newsletter list, therefore I am hoping to contact you this way instead.

  6. Hi Marnie,
    Thank you so much for the rich article. I have been searching for information re alternative aromatose inhibitors. I was diagnosed with BC mid July and have had surgery mid August followed by a month of daily radiation which I finished yesterday. I’ve been prescribed Letrizole 2.5 mgs….and to start in 3 weeks when radiation burning and dermatitis is clear. I have never had to take medication and am very resistant to this given the bevy of side effects. I am 55 yo & post menopausal ( I say I had menopause on a Wednesday!) I’m healthy and lead a reasonably active life and have well grounded fears relating to the AI’s. I’m eating a Keto diet and feeling strong doing so. I am seeking out an practitioner who can help me understand alternatives. I live in NSW Australia.

  7. Thanks so much for the info. After the whole active treatment drill my doctor “recommended” arimidex. After only a few months I was in such pain with frozen shoulder trigger thumb etc. I find out I had osteoporosis. Does Cancer cowboy take me off the drug? Heck no he “recommends” a dangerous bone drug. Then the last straw is the patchy Regrowth of my hair. My 90 year old mother has better hair than I do now. Upon confrontation Cancer cowboy says, oh it does that. I didn’t tell you. So I quit arimidex after only a year. I felt better after only a week. When you are in active treatment and you don’t see results you quit! In this case of arimidex you are going through hell and getting set up for more medical issues with no guarantees. So if we just said no ..that might be the only way to improve conventional treatments

    1. Hi Julia,
      Love your comment. Cancer Cowboy! Hah! Yes, the side effects for some people from Arimidex can greatly affect quality of life. And they don’t seem to work nearly as well as the pharmaceutical companies make out. There are so many wonderful natural aromatase inhibitors and ways to handle estrogen imbalances, and they don’t create the havoc that these drugs are inflicting on us. Thanks for sharing.
      Warmest regards,
      Marnie Clark

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