Hormone imbalance from evening primrose oil?

The estrogen connection

This is an update to my post on evening primrose oil. A comment left by Ann about her aunt gave me some concern and I decided to run more research into the topic. Apparently, her aunt was diagnosed with breast cancer and according to her doctor, the food she ate – namely, evening primrose oil and bean curd (douhua) – may have contributed to that.

I couldn’t find any information regarding the disadvantages of taking evening primrose oil at first and many people I spoke to also told me that it is suppose to benefit women. It was not until I talked to a colleague about Ann’s aunt that she linked the connection between soy and estrogen and that led me to discover that evening primrose oil also has estrogenic properties – although some sources dispute that.

Usage of evening primrose oil may cause problems for some
According to various sources I’ve read, including this, while evening primrose oil alleviates PMS, long term use may actually aggrevate the problems and it seems, most people don’t realize this.  I certainly didn’t!

However, the problems may not be across the board as estrogens are present in almost every type of food that we eat.   It might have to do with a person’s state of health too and since the liver is the organ that removes estrogens, someone with a weak liver may fail to remove estrogens efficiently and hence, lead to their accumulation. When excessive estrogens become trapped in the uterus, ovary, or breast due to stagnation, they overstimulate cell division and lead to abnormal growth such as fibroids, cysts or cancer in these organs. (source)

Soy produces weak estrogens
Soy, on the other hand, have shown many benefits in providing relief for menopause symptoms.  So soy foods, like tofu, contain phytoestrogens, specifically the isoflavones, genistein and diadzein are always said to be beneficial. In a woman’s body, these compounds can dock at estrogen receptors and act like very, very weak estrogens. During perimenopause, when a woman’s estrogen fluctuates, rising to very high levels and then dropping below normal, soy’s phytoestrogens can help her maintain balance, blocking out estrogen when levels rise excessively high, plus filling in for estrogen when levels are low. (source: WHFoods)

soy supplement

Soy supplements not recommended for all
So it looks like  soy isoflavones can provide benefit in reducing the risk of cancer.  In fact, for women who are taking HRT, which comes with an increased risk of certain cancers such as breast cancer, soy isoflavones could possibly provide an additional protective effect.  However, registered dietician Leslie Beck, who is also author of the book Managing Menopause, was quoted in a CBC News article to caution any woman with a family history of breast cancer against taking soy supplement.  “Soy in food a couple of times a week, no problem…In post-menopausal women we’re not sure if soy might act as an estrogen promoter. It acts differently in pre-menopausal women than in post-menopausal.”

A case of estrogen dominance
I’m not trying to be a scare monger here but since I’ve written about the benefits of evening primrose oil, I feel that I have a responsibility to clarify now that I’ve found some new info.  In addition, I was mildly concerned about my menstrual flow for this month and I wonder if taking the evening primrose oil had tipped my cycle the other way round.   It could have contributed to a case of estrogen dominance, causing even more hormonal imbalance for me.

Take everything in moderation
So, I’ll like to state that it’s best to take this in moderation and if you have a family history of breast cancer, you want to be even more cautious.   Of course, the link between estrogen and breast cancer isn’t as straightforward as it involves DNA mutation in cells and hence, isn’t across the board for all.   If you’re interested to find out more, National Cancer Institute has some slides explaining the link.

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  1. pf1123 says

    I know of a colleague who has breast cancer. I tried to discuss with her on the issue of soy products causing zinc blockage. She told me that she was advised not to take too much soy products as they have something in them (I can’t remember) that causes hormones imbalance. However, she also did mention that moderation is key to all kinds of food.

    I suppose thats really true since too much of something might be harmful. Moderation is key.

    I only take EPO when its bordering my menses and I feel a bad PMS is coming. I love mr bean pancakes…but I limit myself to once or twice a week for breakfast and soy bean milk to once in a while.

    • sesame says

      It’s estrogen from soy too. So your colleague is right – moderation is important. I remember you mentioned you take 2000mg of EPO? But if you only take that during PMS, then should be considered okay. Plus you don’t take that much soy.

  2. ann says

    Thanks Sesame for following up on this. We must be careful especially when using or taking something long-term. I’ve also read somewhere that the hormonal cream shouldn’t be used for more than 6 months at a stretch. So, i’m bearing that in mind too.

    • sesame says

      I’m not sure the hormonal cream is the ones containing actual hormones? If that is the case, shouldn’t use them at all cos such cream will inhibit the production of natural hormones.

      The herbal ones are better, but you are probably right about not using them long term but giving break. Going to check out more on this cos I was initially uncomfortable with using herbal creams too but since the other choices are limited, I go with it for the moment.

  3. zhenling says

    thanks sesame for the heads up. but im confused. how much is too much? everything should be fine if we follow instructions in the bottle label right?

    • sesame says

      I can’t say for sure but if you do not take a lot of other food/supplements containing soy, then taking once a day should be fine. Or the other alternative, is to take it nearer the time of PMS like pf1123.

  4. Den says

    I have been advised by doctors not to take any soy products, including miso soup. I have excessive estrogen and that is partly why I am not a strong believer in taking Evening Primrose. However, some women do not suffer side effects but I had read in some articles that even though we are brought up believing that soy is good for us but too much of it is certainly not good.

    • sesame says

      Ah…I see. Not even miso soup?

      So there is some sort of test we can determine about our hormone levels right? Someone told me about this recently. I would like to get mine checked too.

  5. says

    i used to take Primrose Oil for 3-4 yrs in my teens because of my bad cramps. Once I went off it, my cramps were very very bad and I felt somewhat reliant on the PO. Overall, I felt in the short run, PO was fantastic, but long run wise, I was scared of being over reliant… thks for all this info on PO. Gives ppl better understanding of what they are putting into their bodies

    • sesame says

      You’re welcome! I’m glad to find out about this info too…otherwise I will just continue to take it without knowing the possible consequences.

  6. pf1123 says

    oh, the 2,000mg is when I’m trying to sort out my skin issues. Haha…I also have pretty bad PMS during those days.

    Currently, my PMS is not too bad. Tolerable even when I don’t take EPO. But I just take it around that time of the month. I probably take around 1,000mg only.

    • sesame says

      That’s great! :) I think taking EPO by itself shouldn’t be an issue…the only problem are for those who also take a lot of other food containing soy (especially since many believed in their health benefits.)

  7. CT says

    I love all products relating to soy which I used to eat everyday thinking as compared to meat, it was a healthier choice of protein. However, few years ago, I discovered I have fibroids, and the chinese sinseh has advised me to cut down on soy products. Whereas, western doctor doesnt believe in this theory.

    • sesame says

      Oh that’s quite unfortunate isn’t it. I realized that it’s those who dabble in natural treatments that believe in this theory too.

      But glad you managed to overcome the problem. :)

  8. Suz says

    I hope I don’t have to ever take primrose oil!! Then again anything can cause cancer….but who really knows what exactly…is the reason for cancer also…don’t most products have primrose oil in it and what about using the oil on your face?

    • sesame says

      The effects of ingesting should be different from the effects of topical application. Your skin may not apply so much of it. Anyway, it’s not across the board for all…probably affect certain age group more. In addition, it should be viewed in totality with your overall diet.

  9. grace says

    It is valid and true. I have endometriosis and after much research about diet to watch out for endometriosis, soy is a big no no and should only be taken in very little amount. (which I have taken so much before I discover I have endometriosis). Soy contain phytoestrogen, and the process of making beancurd, soy protein, powder etc has contain alot of chemically induced estrogen, whihc is bad. The only good soy that is recommended is the organic miso, whereby its proceed by the traditional fermentated method that is able to keep the good phytoestrogen.

    • sesame says

      Ah…no wonder the Japanese are okay with their miso and tofu. Their grade is better! Thanks for highlighting this. I didn’t even know that the beancurd contain chemically induced estrogen.

  10. says

    I never taken any primrose oil before… or anything that will relief PMS (I think I don’t one.. consider me lucky? But I do have breakout!)

    What I’m trying to say was.. I LOVE tofu!! (If I eat that almost everyday.. does it consider too much??)

  11. fwy says

    I used to take EPO many years ago but stop when they do nothing for my PMS. I only eat soyabean once in awhile.

    • sesame says

      I recall you mentioning in one of your comments that PMS did not help you. It didn’t do anything for me till I started using Kordel’s but now, I’m thinking twice if I should continue…

  12. annie says

    how abt strengthening ur liver? since weak liver cannot expel excess estrogens and so on.. *ponders*

    i need to take EPO for my skin problem. but im taking one capsule of 1000mg a day, together with fish body oil & flaxseed oil (1 capsule of 1000mg each).

    hope this is not considered too much intake.

    • sesame says

      Maybe…but I find it complicated since I don’t know what can strengthen the liver.

      1000mg is the recommended dosage but it really depends on individual…what else they eat…how old are they…etc.

  13. ann o nymus says

    ummm….good info. weak liver? looked at the sites you linked to and read pretty much the same, from the horses mouth 😉 she sells products, but also gives advice on how to do it yourself.

  14. ann o nymus says

    the main article was on gallbladder cleansing, but she did mention this in regards to liver (copied and pasted from her site);
    avoid or minimize foods that weaken the liver or spleen such as white flour, white sugar, caffeine, chocolate and deep fried foods. According to Chinese medicine, cold foods, cold drinks, citrus fruits (unless you also eat the outer skin, which is not advised unless the fruit was organically grown because pesticides often sink into the outer skin), tomato, banana and even salad should also be avoided or minimized because they weaken the spleen and kidneys. Spicy foods should also be avoided, especially ginger and cinnamon which tend to congest the liver.

  15. debbie says

    aw man! i just started taking an oil blend of flax and EPO (barclean’s essential woman) for my PMS. It’s actually been helping when nothing else has. I was JUST thinking that I would only take it during the 2 weeks I suffer from PMS and take a regular 369 blend the rest of the time. Thanks for posting this.

    • sesame says

      I think it’s okay if you’re not taking too much other soy products. Or like you suggest, not take it everyday but only nearer to PMS.

  16. Dalyn says

    hi, i have just started taking EPO for two days. i have issue with my eating habit that is i seldom eat. … im underweight so people around me suggested i try primrose oil. (i wonder why? =p) but, the thing is, even i just started (one pill only per day), im having stomach cramps the next day. i stopped taking the pills on my third day, the pain reduced. now, im not so sure if i should continue eating it. any suggestion or am i being overprotective / paranoid? also, i love soy bean milk. i drink every morning. now that i read your article, i think i would change that routine to once a week.
    thanks =)

    • sesame says

      I’ve not heard about the association between EPO and weight. I think it’s better to be careful what you take. EPO and soy are always said to be good, but apparently, not necessarily so for everyone.

  17. claire_cemolina says

    thank you for posting that! so glad i stumbled across this, thats interesting. But like you said, everything in moderation!

  18. laura says

    I have tried evening primrose oil over the past few years, and it always seems to affect me negatively. It makes my cycles alot longer and heavier, and also irregular. It will give me 2 cycles in one month. The only reason I kept trying it was for my skin, which seemed to help the dryness. But it just isn’t worth the irregular hormone imbalance for me– it makes mine worse!

    • sesame says

      Laura: Since writing that entry, I had the opportunity to read further about EPO and posted something about it here:

      Apparently, some pple are better off without it.

  19. Teresa says

    I have been so tired lately, my mood swings have been awful and serious breast tension. I went to the doctors who gave me a blood test, the results were good, I am not yet going through the change. How ever, i feel rubbish, so i started to take primrose oil and soya lsoflavones which suppose to help women. Please can anyone tell me if i am taking the right food supplement.

    • sesame says

      If you suspect yourself to have hormonal issues, then do not take so much of these supplements. It’s better to be cautious…

  20. Ni says

    i used to take EPO for years..initially it helped a lot for PMS, but after 45, i realised its giving me lots of bloating, breast tension and looked it increased PMS symptoms..so i stopped and feel better..but i would like an alternative hormone producing agent..currently i am taking a soy drink powder a day (just stared four days ago), can anyone please suggest something?? many thanks

    • sesame says

      It’s best to sort professional advice. Why not try some of those in holistic med training. I use a herbal cream containing chasteberry extract and it seems to be helping my PMS.

  21. Monika says

    Your website offered me the most interesting information. I have taken EPO on and off for several years for hormonal balancing. It did help with pain during menstruation. That was in my 20s and 30s. Now in my 40s after a 5 or 6 year break, I started again 3x a day, 2 capsules religiously for over two weeks to aid in varicose veins, slight depression, heart health, and again hormonal balancing. In 39 years of menstrual regularity, almost in sync with the lunar cycle, I started bleeding after just 17 days since my last period. I was convinced I was finishing ovulation, but the blood (bright red, with some clotting, not quite as strong as normal) was shocking. Could the EPO have something to do with it? I also suspect some slight issues with my liver or gallbladder, as I can’t drink more than a glass of wine, and don’t feel too great after fried foods – but could EPO affect estrogen levels this quickly after such short a time span?

    • sesame says

      It might be the EPO, but it might be the hormonal issues. Look into some of the hormonal issues affecting this age group eg. perimenopause is one. I thought I had this issue but it seems that I was having problems with too much toxins and it helped when I did a detox. But I might be having some problems with liver too. The best is to read up and find some help from the right source.

      I wrote a few articles about detox. This is one:

  22. Joan says

    Everyone, watch the following video on soy’s potential to raise IGF-1 (human growth factor) twice as much as dairy: http://www.youtube.com/watch?v=mHYFOJBU434
    I’m taking primrose EPO for hair. It increase estrogen by inhibiting 5-AR (reduces androgen receptor transactivation = no DHT); the remaining testosterone hopefully then converts to estrogen. Without estrogen one cannot grow hair. EPO, unlike soy, also inhibits IFG-1 signaling pathway, so it’s anti-cancer. Therefore, I believe a little EPO acts like a harmone balancer and reduces DHT. I eat soy only two-three times a month.

  23. Riri says

    Oh, I’m glad I found your website. Ive been a breast fibrocyctic patient for the past 3 years. Ive been married for 1 year and nothing has changed towards the cysts anyways (docs said marriage may imbalance my hormones in some way).

    I’m thinking of taking either EPO or FlaX Seeds to balance my hormones, but unsure which one and which brand is trustworthy. My hope is to get rid off the cysts as well as to fall pregnant too. Can anyone suggest pls?


    • sesame says

      I suggest you don’t take EPO. As for flaxseed, it maybe something to consider but have you done any test on your hormone level?

      In terms of brand, I usually go for Kordel and find them good. Btw, which country are you based?

  24. Juliana says

    Hi all,

    I switched to a high raw vegan diet and was consuming flaxseed almost daily for several months. i was grinding it up and then blending it in a green smoothie. (about 1/4 of cup a day maybe?)within a few months i started noticing water retention, constipation, mentrual irregularities including clotting, and i gained 20 lbs and was hypoglycemic. all of these other symptoms and only recently realized i was suffering from estrogen dominance. estrogen dominance can also cause hypothyroid which i also have.

    i had no idea, but flaxseed has 3x as much estrogen as soy. i do not know why the public is unaware of this.

    i was not consuming any other major phytoestrogens, except for sprouts on a regular basis and certain fruits and herbs (cherries, apples,ginseng, etc). i realized that taking flaxseed, much like consuming alot of other phytoestrogens is like taking an estrogen supplement, at least in my experience. and for most women extra estrogen is just something we dont need.

    • sesame says

      Yes, it seems flaxseed oil is not for everyone. I can’t take it and I wrote about it here:

  25. melody says


    I suffer from severe endometriosis. Fully agree that the EPO is not suitable for certain people especially people with cyst, fibroids and breast cancer.

    I thought EPO could relieve my menses cramp since everyone tell me it’s good and within 4 mths of consumption i started to hv few fibroids.

    So people with weaker liver or estrogen dominance condition (which most women are nowadays due to the processed food and environment) should avoid taking them.

    Mainly soy, EPO, promeganate, dang gui and flaxseed should be avoided.

    • sesame says

      Thanks for your inputs. It’s really important to learn how some of these supplements should be taken in moderation in line with our state of health.

    • sesame says

      I think you should be careful taking EPO with your condition. Maybe ask your doctor for opinion.

  26. Sam says

    I think I might be low in Estrogen. I got on a birth control pill awhile back that was higher in progesterone and lower in estrogen (but still high). Worst experience of my life- felt really depressed and had hair loss. Well, I still have hair loss and pretty bad pms. (I start feeling like how I did on the pill a about a week before my period). It makes me think I’m low in estrogen (I’m really slender too). I was looking into natural ways to increase my estrogen levels and saw evening primrose oil might help. I’ve seen conflicting reviews of some people saying EPO actually lowers estrogen, which is not what I want. Some have lighter to no periods while taking EPO as well. This is weird to me, since estrogen is supposed to make periods heavier. So now I’m trying to find other natural ways to increase estrogen if EPO doesn’t work. Also, for those of you out there that have “weak” livers, I’ve research something called N Acetyl Cysteine. It’s an amino acid and it helps clean the liver- supposed to be very good for it.

  27. bunny says

    Im 21 years old,on early march last year I start taking EPO , 1000mg a day and sometimes 2000mg a day as I heard it help to enchance hair structure,body health hormone and etc,and after a month I also take E trienol which is an vitamin E supplement (function in anti pigmentation,sunscreen protection,antioxidant and anti-breast cancer which help to prevent cancer in women),after a month I found a lump in my breast about 3 cm x 4 cm,It is considered giant and afterward I was diagnosis with fibrodenoma,its benign lump in breast but cause painful during menstrual and may became bigger,my doctor says that there is no specific cause of fibrodenoma occurence but usually it caused by hormone imbalance in women,typically estrogen was in high level.I wonder if actually taking EPO and other supplement caused my estrogen level to boost up.Im going for fibrodenoma excision next month to remove it.I would just like to share :) be careful in taking supplement.Better to take an organic herbs such as ‘Mahkota dewa’, it is a herb that drink as a tea and have an antioxidant effect and cancer prevention esp for tumour.my aunty drink it and her breast lump shrink after some month.I would like to try it but couldnt find it anywhere.

    • sesame says

      It’s best to be careful with supplements that has effects on stabilizing hormones and such eg. they’re said to help with PMS and so forth. A safe bet is not to consume too much if you don’t have issues and not to consume at all if you have hormonal issues.

  28. bella says

    I’m happy to come across your article. I have been trying to find more information on the topic and always keep my eye out. I was recommended evening primrose oil to balance female hormones by an esthetician I went to in 2010. She recommended it to me for hormonal acne on my jawline. Shortly after this (within a few months), I started getting tons of little pinpoint red dots all over my arms, breasts, and a few on my legs. These are known as cherry angiomas and after researching these red spots further, many holistic doctors think it’s caused because of an imbalance in estrogen in certain women — but the medical community doesn’t really delve into the cause or prevention of cherry angiomas because they don’t cause any serious health concerns. It’s very frustrating to have these because I’m still young.

    I have an empty bottle of evening primrose oil capsules now and I’m afraid to ever take one again. I was probably taking two a day. I wasn’t overdoing it. I finally stopped this month after realizing that this might be the cause. These have been praised in other communities as being great for skin and some women even say they make their breasts larger and firmer..lol. I think the latter is wishful thinking.

    I’m wondering if I can use the remainder of these capsules on my skin as a serum. I kind of don’t want to risk it and might just end up tossing these because I believe they have contributed to these spots.

    • Sesame says

      Yes you can! I wrote about using it to help acne here http://www.vivawoman.net/2008/11/12/diy-beauty-evening-primrose-oil-for-acne/.

      Glad you found out early that it’s not working well for you when you ingested it. A lot of women just assume EPO is great but it really depends.

  29. Genf20 says

    You’re so great! I don’t suppose I can learn something like this before.
    So good to find someone with some creative ideas on this subject.
    really thanks for bringing this up. this website is something that is needed
    online, somebody with somewhat originality.
    great job for bringing something new to the internet!

  30. Angelica says

    Thanks for the article. Also, I think you mean “scare monger” (or rather “fear monger”), not mongrel. Signed, your friendly neighborhood editor. :-)

    • Sesame says

      Thanks for pointing out! Haha…it’s one of those cotton swab, cotton swap errors. Definitely doggone…LOL.

  31. nicole says

    hi there! I have been taking epo for months now, 3000 mg a day for acne and it hasnt done a thing! now, all of a sudden im having hair loss like crazy!! is there any correlation that you know of between hair loss and epo?

  32. Lady Pains says

    Congrats on a well-written article. You don’t make any baseless claims and include disclaimers where necessary. Sources provided throughout. Good work!

    I have SEVERE menstrual cramps that have recently gotten worse (along with tons of other newly arising symptoms that suggest endometriosis or hypothyroidism). Evening primrose used to work like a charm for my cramps but now seems to affect my mood negatively. Stopped working for cramps as well. I’ve no idea what this means, but I’m considering quitting it.

    Lesson: Hormones are complex and not always easy to manipulate in the direction we want them to go. Imbalance can affect every organ of the body, including the brain.

    • Sesame says

      From having conversed with a number of women who use EPO, my guess it may work differently for different ages. Try fish oil for PMS and cramps.

  33. pinky says

    hi there,

    i hv not had my periods for almost 6years now. i went to the doc and tests revealed hormonal imbalance. i hv tried conception drugs that gave me heavy flow for 2 weeks non stop, so i stopped it. now i was asked to take epo and after reading this, i dont know what to do again. i really want to try it out. any advice? am very late 30’s.


  34. ALEXANDRA says


    • says

      Several women who suffered from premenstrual symptoms, including migraine, had their serum estrogen measured before and after the “carrot diet,” and they found that the carrot lowered their estrogen within a few days, as it relieved their symptoms.

  35. Nami says

    Do not carelessly take EPO. I thought it was going to solve my problem with PMS but after 3 days of taking it, I started having these big pimples on my face. Some people say that it’s normal since I was just starting to take EPO so I took the risk. After maybe a month of taking it, 1000mg a day, I now have back acne and pimples have never left my face and even my chest. I also am experiencing hair loss. It is very scary. So if you guys know a solution to my problem, please give me some advice. I’m going crazy about this.

  36. Kay says

    4 years ago I took EPO and for the first time in my life suffered from debilitating anxiety and depression. Even since that dark path has been created, it has been a struggle not to go down it again. I would suggest anyone trying to balance their hormones to do so with a healthy diet and lifestyle and forgo supplementation of herbal remedies. They are just as potent as pharmaceuticals which I also would be extremely leery of taking.

  37. LB says

    Thank you for this clarification. I started taking evening primrose to help with hair loss and not only did it throw my menstrual cycle off, I became tired, irritable and could cry at a moments notice. I stopped and within 2 days all of my symptoms disappeared. Nothing about these possibilities on the bottle and no mention of them in the book that gave the suggestion (written by an M.D. too).

  38. Nidhi says

    Thank you for bring this important information. I have just started taking EPO but now i have to think whether to continue or to stop taking it. What are other options for bringing hormones into balance?


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