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The "Do not take if...." List...please add...

nicolerod Member Posts: 2,877

Hi Ladies... I believe someone mentioned a few weeks ago in the Ibrance thread that we should start a list of things "we should not take" if we are taking Ibrance and some for letrozole or Hormone positive. So I figured I would start this with relation to:

Hormone Positive Breast Cance/Ibrance/Letrozole

The ones I know about are:

1. Green Tea Extract (Ibrance)

2. Tumeric/Curcurmin (letrozole (see below) & Hormone Positive)

3. Milk Thistle (letrozole see below)

4. Quercetin (letrozole see below)

5. Resveratrol (letrozole see below)

(those last three I added in from Lilahope777 :) and she explains why )

6. Oil of Oregano (Ibrance and Letrozole) (thanks Husband 11)

7. Grapefruit

8. CBD Oil (see below post that it has properties similar to grapefruit)

A nice very smart lady lilahope777 posted the following in the Ringworm medication thread and she said I can share it here.

I believe the "not recommended" is due to taking Letrozole (not the hormone positive breast cancer) with the exception of the Resveratrol. Letrozole is metabolized by P450 system enzymes: CYP3A4 and CYP2A6.


Milk Thistle:

  • Do not take if .....You are taking cytochrome P450 3A4 substrate drugs: Milk thistle may increase the risk of side effects of these drugs.
  • Herb-Drug Interactions: Cytochrome P450 3A4 substrates: Milk thistle inhibits cytochrome P450 3A4 (4) and can affect the intracellular concentration of drugs metabolized by this enzyme. However, conflicting data indicate no such effects (13) (14)(38). In another study, consumption of milk thistle did not reduce levels of indinavir, an AIDS drug (15).



  • Contraindications: Patients with hormone-sensitive cancers should use caution, as resveratrol—at concentrations between 3 and 10 μM, similar to those needed for its other biological effects—exhibits estrogen-like properties and activates transcription by both estrogen and androgen receptors that lead to the stimulation of cancer cell proliferation (18).

This all said, I would love to be wrong about my understanding of the above! I will continue to research.

So in addition to those 5 if anyone has any to add please feel free.

Nicole :)


  • Anewbreath
    Anewbreath Member Posts: 122

    This will be very helpful NicoleRod! I’m trying to intergrade supplements but I don’t want to jeopardize my treatment plan of I/L. I know tamoxifen metabolizes the same pathway as letrozole. I’m wondering if anyone can share if berberine or lycopene has any effect on I/L? Thank you for starting this thread 😊

  • lrsreyes
    lrsreyes Member Posts: 23

    I am of Faslodex . Her- and still taking turmeric. I don't want to jeopardize my treatment plan.


  • OnTarget
    OnTarget Member Posts: 124

    Thank you, very useful!!

  • husband11
    husband11 Member Posts: 1,287

    Oil of Oregano is a potent inhibitor of both Cyp2C9 and Cyp3A4. Both palbociclib and letrozole rely on Cyp3A4 metabolism, thus it should be avoided. As well, xeloda (capecitabine ) is also metabolized by cyp2C9 and should not be combined with oil of oregano.

    JACK5IE Member Posts: 654

    Thank you for starting this thread NicoleRod. It seems there is something new everyday that we shouldn't be doing.

    JACK5IE Member Posts: 654

    I'll add this to this thread. It has a few things at the bottom that shouldn't be taken with ER+/PR+ cancer.

  • nicolerod
    nicolerod Member Posts: 2,877

    Thanks Jack5ie..I totally agree with you about there being something new everyday...right?!! Its crazy.

    I am not going to add them onto the above list because its a lot of things and because I read on the folic acid page says that vegetables like beets, spinach can be bad. I just think we should keep the list to specific things that we know are bad with relation to supplements and such because it doesn't say how much spinach or asparagus is bad...there is too much space there. I hope I am explaining that so everyone understands.

    Thank you though for that information I am sure seeing what foods to avoid will be helpful for all of us. :) I personally wish it said how much is bad. :(

    JACK5IE Member Posts: 654

    Totally understand NicoleRod. That's why I just offered the link.

    The main 'don't take this' on the one page I linked to seems to come from the specific supplements mentioned. The site does have does great information and links to studies as well though. I use it for reference a lot.

  • divinemrsm
    divinemrsm Member Posts: 5,896

    One of the above links mentions folic acid supplements are not good for hormone positive bc. Does anyone take a multivitamin that does not contain folic acid? They are hard to come by. I feel like my body needs a daily multivitamin but hesitate, not knowing if something harmful that promotes the bc is in them.

    JACK5IE Member Posts: 654

    My MO told me not to take any vitamins with the exception of Vitamin D because of the cancer being in my bone. They said in the case of Vitamin D the benefits out-weigh the possible risks. But they did also say the cancer feeds on an abundance of supplements. Some doctors believe this, others don't. My previous MO before my cancer became metastatic never told me anything about vitamins. I took an abundance after my first round of treatment. Whether that had any impact on my cancer turning metastatic, I'll never know. But I'm following my doctor's advice on this now.

  • nicolerod
    nicolerod Member Posts: 2,877

    I do not take a multivitamin but I did start taking the Vitamin E (from Joes protocol- ringworm med for dog) its the Life Extension brand. However I am only taking it 3 times a week. I know Bev had mentioned she heard Vitamin E is not good for Hormone Pos. but I can't find anything conclusive about it?

  • nicolerod
    nicolerod Member Posts: 2,877

    I wonder if the Gamma E can make Bilirubin rise??

  • micmel
    micmel Member Posts: 9,803

    ibrance. No grapefruit or pomegranates! Or anything derived from them ! Can make the medicine more potent in your blood. I read it on the insert that comes with the medicine. Be careful!

  • nicolerod
    nicolerod Member Posts: 2,877

    Will add that , I knew that but thought everyone knows that one. lol but yes it needs to be added thank you ;)

  • simone60
    simone60 Member Posts: 952

    The CVS speciality nurse told me to avoid Blood red oranges also with ibrance. It can make ibrance more potent.

  • nicolerod
    nicolerod Member Posts: 2,877

    Santa adding this here bc I put it in the other thread but probably belongs here...

    I know you mentioned if antioxidants fed cancer yours would be the size of a basketball now LOL but you have to admit that everything effects everyone different. Some people on this board eat cakes and such and they are in stage 4 NED for over 8 years..just read about it in the thread "can we talk sugar/fresh fruit carbs etc". I am taking the Vitamin E so I do agree with you but I don't know that it will work just fine for me and help me. Just have to wait and see. (I will add this into the other thread Do not take.. as well since it probably belongs there more than here)

  • lrsreyes
    lrsreyes Member Posts: 23

    I just read the good news that my TM has gone down from 266 to 124 after stopping green tea extract. Before treatment it was 255 and I feel great ( no aches ) so I have been working hard in my yard ( painting, power washing , planting monkey grass ) . I feel great since I have accepted my stage IV diagnosis and all my aches are gone. Thanks for your input Nicolerod!!!

  • DorothyB
    DorothyB Member Posts: 143

    Irsreyes - what is TM ?? I've been putting matcha in my morning smoothies.

  • nicolerod
    nicolerod Member Posts: 2,877

    DorothyB ...Tumor Markers.

  • marijen
    marijen Member Posts: 2,181

    Green tea extract can be liver toxic:


  • simone60
    simone60 Member Posts: 952

    Hi everyone. You need to add CB D oil to the list. It is similar to grapefruit. It uses the 3A4 enzyme and may alter the metabolism of ibrance causing too much of the drug in your system.

  • lilahope777
    lilahope777 Member Posts: 27

    Re: Ribociclib (Kisqali) Potential Drug Interactions - A Poster Created by Novartis for the Symposium Oncology Nurse Advisor Navigation Summit; June 15–17, 2017

    I came across this "poster" regarding Kisqali, prepared by Novartis. Very surprised to see Simvastatin on the "Prohibited" list.[email protected])7042%20MASCC%20DDI%20poster%20M1.1.pdf

  • DorothyB
    DorothyB Member Posts: 143

    marijen - it can be so confusing. These two indicate that a reasonable amount might be helpful: "Matcha green tea (MGT) inhibits the propagation of cancer stem cells (CSCs), by targeting mitochondrial metabolism, glycolysis and multiple cell signalling pathways" "Green Tea Consumption and Risk of Breast Cancer and Recurrence—A Systematic Review and Meta-Analysis of Observational Studies"
  • marijen
    marijen Member Posts: 2,181

    Green tea is good, but the extract can be fatal. I drink green tea most every day.

  • BevJen
    BevJen Member Posts: 2,341

    Wow, that poster had a lot of interesting information. It also listed the following things as prohibited for use with ribociclib (kisqali) -- so I wonder if they are also off limits with the other CDK4,6 drugs?

    Black cohosh(hepatotoxicity, hormonal e ects)

    Fish oil

    Gingko(palpitations, QT prolongation)

    Ginseng(CYP3A4, QT prolongation)



    Milk thistle

    Saw palmetto

    St John's wort(CYP3A4)

    Also, there were a fair number of antibiotics that also were on the "prohibited" list?

  • olma61
    olma61 Member Posts: 1,016

    Like JACK5IE , my MO is against supplements. Some that I was taking at diagnosis, she did not know what they were or why I would take them. (COQ10, 5-HTP) She's completely conventional. But she did recommend calcium with D3 because I also have bone mets. After I asked a few times about different vitamins, she said I was "allowed" to take a multivitamin. But, not only do most multivitamins contain folic acid and just about every other vitamin & mineral known to man, they usually have megadoses of those vitamins. Which, the nutritionist I saw and many things I have read advise against mega-dose vitamins for cancer patients, particularly B vitamins.

    I came across a study that found that men who were taking huge doses of B12, like thousands of times more than the minimum daily requirement, had a higher incidence of lung cancer. OK so this is just one study about one vitamin on men, and not about breast cancer at all. But that did make me cautious about mega-doses of vitamins and my nutritionist then confirmed it.

    I have found some supplements in CVS that do not have megadoses and just have at or near 100% of the minimum daily requirement. But then they change formulas or discontinue the product and I have to search again.

  • iulia
    iulia Member Posts: 3

    Thank you for sharing this with me in the other thread. I just asked a question about the letrozole and curcumin in Joe Tippen's FB group about it and it is pending approval. I will try to find more information. Until we are certain it is safe, she will stop the curcumin.

  • sadiesservant
    sadiesservant Member Posts: 1,875

    Hi All,

    Starting Verzenio next week and the specialty pharmacist specifically asked about grapefruit and St. John’s Wart. She was also concerned about NSAIDs but that is due to the potential problems from bleeding. When I was on Ibrance they advised against green tea.

  • iulia
    iulia Member Posts: 3

    While searching for more information about Letrozole + curcumin I came across two studies on Pubmed - "Aromatase inhibitor letrozole in synergy with curcumin in the inhibition of xenografted endometrial carcinoma growth" and "Cancer-Linked targets modulated by curcumin".

    The first is about endometrial carcinoma growth still shows that the two can work together synergistically. The second briefly states that curcumin blocks the proliferative action of breast cancer cells by downregulating ER activity and it can reduce the toxic effects of the current drugs (Letrozole is one of the drugs mentioned).

    Last, I came across the blog post "Curcumin and Letrozole: Not a problem" by Dr. Jacob Schor. I know that he is a naturopath and some may view them as quacks. However, he cited many studies from Pubmed and peer-reviewed medical journals.

  • Wanderingneedle
    Wanderingneedle Member Posts: 220

    This is a database from Memorial Sloan Kettering. It was mentioned at a conference I attended last month. There is also an app you can download.