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Education > Our Blog > Why So Many of Us Quit Taking Tamoxifen
Why So Many of Us Quit Taking Tamoxifen

April 05, 2021

Why So Many of Us Quit Taking Tamoxifen

by Kim Horner

Soon after I tested positive for a BRCA2 mutation in 2009, my doctor urged me to take tamoxifen to reduce my breast cancer risk. Tamoxifen blocks the effect of estrogen on breast tissue. For previvors, it reduces breast cancer risk by up to 40 percent when taken for five years; the protective effect continues beyond that period. Doctors also prescribe tamoxifen to treat hormone receptor-positive breast cancers.

I was 41 at the time. My son was still a baby. I was terrified of developing cancer but also scared of taking a medication that can cause hot flashes, night sweats, vaginal discomfort and increases the risk of uterine cancer, blood clots and stroke.

Based on my doctor’s advice, I filled my prescription and started taking tamoxifen in July 2009. The hot flashes began after just two days. I started to have difficulty concentrating and I couldn’t focus at work. A couple of weeks later, I experienced ongoing pain in my pelvic area. After trying tamoxifen for about a month, I quit–I had to be able to get through the day.

Because of these side effects, many patients do not begin or complete treatment with tamoxifen. That’s why I was glad to see FORCE’s eXamining the Relevance of Articles for You (XRAY) article about research that studied why patients stop taking these medications and what can be done to address the issue.

According to the XRAY article, the study was the largest survey of hormone therapy use among online patient populations. More than 2,500 participants completed a survey about why they did not begin treatment or why they stopped it. If they began treatment, the survey asked respondents about their side effects and how they managed them.

Based on the survey results, tamoxifen causes difficult quality-of-life issues for most patients. It’s concerning that only 40 percent of respondents reported finding relief for those symptoms. I can relate to the comments that doctors did not take their patients’ side effects seriously. I felt that my doctors presented side effects as something you simply have to live with. However, waking up in a pool of sweat, having frequent hot flashes and not being able to concentrate at your job is not sustainable.

It was encouraging that the study found that a healthy diet, exercise, physical therapy, yoga, vitamins and even medical marijuana helped some patients. I hope the findings lead to more research to find ways to help patients manage the side effects of hormone therapy so that more women can benefit from these important medications.

After I quit taking tamoxifen, I decided to have my ovaries, fallopian tubes, and uterus removed. After my surgeries, I tried going without hormones. That lasted a week. My doctors approved a very low dose of estrogen for a few years to help me transition into menopause. I have not taken hormones for several years and am doing well.

Kim Horner is a FORCE Texas Impact Leader in Dallas-Fort Worth. She is the author of Probably Someday Cancer: Genetic Risk and Preventative Mastectomy (University of North Texas Press, 2019). The book includes a foreword by Sue Friedman, executive director and founder of FORCE.

Posted in: XRAY , Quality Of Life
Tags: Breast Cancer , Cancer Prevention , BRCA2 , Prophylactic Surgery


June 1, 2022

My cancer was grade 2, and I had my left breast removed (tissue saving surgery). My lymph nodes were clear, but they still had me taking Tamoxifen because I was hormone receptor positive. I'm 78, have always been very active, but now I have increased joint and muscle pain. When I E-mailed my oncologist that I was discontinuing the meds, she said "Thank-you for the update. Hope you feel better soon and please let us know if anything changes." I'll see her late this month and will question her answer. In the meantime, I am searching just how long it takes Tamoxifen to leave the system. I want to return to running and weight lifting without all of this pain. Any advice would be appreciated.


October 30, 2022

Misty says:
I have read that it could take 3 or 4 months to leave your system. I see that it's been that long since your comment, so I hope you are doing well!


October 7, 2022

Rita says:
I started taking tamoxifen but brain fog, empty mind and irritable stomach plus tiredness are really worrying… I wish doctors would give us individual risk assessment instead of just prescribing it to everyone. I don’t have a medical team. In my country it’s just check up appointments with oncologist every six months…


November 17, 2022

Key says:
I started taking tamoxifen last year. My symptoms are getting worse. It's not even the sweating for Me. My muscles are starting to ache all over, unwanted hair growth. I can't sleep for over two hours to the point where it may become hazardous to drive. When I complain it like the doctors just brush it off.


July 23, 2022

Brenda says:
I’ve been taking tamoxifen 3 years since bilateral Mastectomy. This was for estrogen receptive +, non-hereditary cancer in right breast. Previous cancer 26 years ago in same location (had lumpectomy followed by chemo and radiation) I am now 62 and absolutely hate being on this drug. Seriously considering stopping it short of the next 2 years. Hot flashes, hair loss, brain fog etc. I’m having a hard time finding legitimate/compelling reasons to continue. Anyone in a similar position???


October 12, 2022

Maggie says:
Yes! I tested being off of it for 1 week, 2 times this summer and had immediate results. So fast forward to this week October, I haven't taken it for 3 days and already feel better. My brain fog is lifting and so is my mood My joints don't hurt as badly and am looking forward to no more muscle cramps. I am working on my mental part as far as fear, guilt, will see how this goes! So grateful to have found like minded ladies!


September 15, 2022

Jenny Eleni says:
When I read what you wrote I felt as if I was “looking in the mirror.” I detest Tamoxifen. Despite counting calories, consulting with a dietitian, hiring a personal trainer, I have gained 40 pounds! I grow a Tamoxifen beard every day and use tweezers. Hot flashes, stinky breath, brain fog, mood swings. I’m frustrated! December will be 3 years and I’m tempted to not even take Tamoxifen in the morning. I don’t see how anyone stays on the medication for 5 years. I’m considering to stop taking it but I’m terrified the cancer will return.


November 12, 2022

Maryellen Thomas says:
After my estrogen positive breast cancer Diagnosis, radiation & partial mastectomy I began tamoxifen and it was like living in hell! My hot flashes were off the charts, all day and night. I couldn’t take it anymore so my Dr finally took me off them after 3 years. That was 16 years ago. So far, do good..


October 5, 2022

Denise says:
I did stop taking the medication, last Wednesday. I feel like my old self again and even lost 5 pounds without trying. The side effects were too much for me. I do worry like you about the cancer returning. I have only taken it for 3 months and it was the worst 3 months. I’m happy again.


October 18, 2022

Julia Del Vecchio says:
I was diagnosed with hormone positive breast cancer 2 years ago at age 49 to the right breast. I had the recommended lumpectomy with negative lymph nodes. Chemo and radiation was not recommended as beneficial considering the very slow growing and otherwise non aggressive behavior of my cancer. I was starting on Tamoxifen and sadly my life has been a constant struggle for the 2 years I have been taking it. The very poor sleep alone was impacting every aspect of my quality of life. The constant bone and joint pain made exercising more challenging. I have always been very thin and now I have stubborn fat all over especially around my belly. I have abdominal bloating and discomfort. I have brain fog and find it hard to concentrate at work. I have fatigue and lack of ambition due to all the above. My oncologist insists I need to continue taking tamoxifen despite all these symptoms and prescribed a drug to help me sleep. I tried it and it did absolutely nothing for me. I want to live a long life as much as the next person but not if it means suffering for 3 more years of this. I am athletic and do hot yoga regularly eat healthy bla-bla-bla my efforts have not overcome the side effects of tamoxifen. Next my oncologist suggested another drug for depression…really…even though I’m going through all this I am still a joyful person. I’ve always have been optimistic and happy. I just want a good nights sleep. Tamoxifen is such a cheap drug there aren’t any incentives for drug companies to fund studies on the most therapeutic dose for women whilst minimizing side effects. The recent one out of Italy was promising but specifically for hormone receptor positive stage 0 ductal carcinoma in situ. Millions of women are on tamoxifen. We deserve more research on this drug and better ways to minimize the awful side effects. I believe it could mean decreasing the dose for some women depending on the behavior of their unique breast cancer because all cancers behavior is different for every person. I can’t believe we still rely on slashing, burning and using poisons to try and kill the cancer. Chemo of course being the worst. I am very sympathetic to my fellow sisters that have undergone chemotherapy or radiation. I understand that I am fortunate to have caught my cancer early. I am very grateful for this. But when considering quality of life; I have chosen to take my chances and live out the rest of my years without suffering the nasty side effects of tamoxifen. I didn’t even mention the darn hot flashes.. I am leaving out the rest of the other side effects because those are distressing but not directly impacting my health. I have hopes that perhaps if not our generation but the next will not suffer the horrific treatments of today. Better yet not get cancer in the first place. Prevention is key.


May 4, 2021

Deinya Mautz says:
My mother was a 34 year survivor, diagnosed in 1955. When the opportunity to participate in the initial tamoxifen study there was no question of what to do. My participation was completed without difficulty with the exception of increased hot flashes. While they may be uncomfortable at times, hot flashes are NOT a terminal disease! Having this approach and hoping that if my participation could help even one woman, continuation was not a question. Yes, several years later I, like my sister, was diagnosed with breast cancer. Given the family history the general consensus was that perhaps the tamoxifen delayed onset for 10 or more years. When later genetic testing showed positive for Bracha 2, I decided to have a complete hysterectomy as a preventative measure. Yes, I have had cataract surgery but given my age at the time, the occurrence was considered age-related and not attributed to either tamoxifen or the 4 doses of chemo following surgery. I would do it all over again.


September 7, 2021

Clover says:
Thank you for sharing your experience. I had been only recently past menopause when diagnosed with early stage breast cancer, and prescribed Arimidex. It’s similar to Tamoxifen, but supposed to be for post menopause. I lasted less than 2 months on it. Couldn’t get out of bed, cried a lot, joints all hurt quite a bit (and I walk daily and do yoga, so couldn’t have that happening!) I’m glad that you found alternatives to that awful drug, and hope you are doing well!


October 13, 2021

Sherry Hayes says:
I had DCIS 14 years ago and left breast I had 37 radiation treatment I decline to take tamoxifen at that time now I'm having a little blood come out of my right nipple when it is squeezed Mamo and Mr I was negative doctor wants me to go on tamoxifen for five years I really don't want to start this would like to know more about side effects I have had a complete hysterectomy when I was 23 I am now 65 thanks for any information


August 15, 2022

Karen Admire says:
I am 58 and was diagnosed with early stage hormone receptive breast cancer right breast in 2019. I decided to have double mastectomy due to my wanting reconstruction (later discovered Precancerous cells in the other breast) I can’t remember my exact score for chance of reoccurrence, but it was definitely extremely low. The dr put me on tamoxifen for five years. I have since gone through menopause and have had minimal side effects. The one side effect I am having is so bad that I am considering stopping the tamoxifen. I’ve gained 30 pounds on this medicine and majority of it is belly and bloating. I believe this is due to the cortisol in tamoxifen. I am going to discuss further with my oncologist before I stop taking it


April 26, 2022

Irmarie says:
The side effects are worth my health. I did it for my daughter. It’s not easy. Now I am at 20 days left of the 5 years in 20mg tamoxifen. Can’t wait to feel like myself again. With no night sweats until my real menopause comes along!


September 27, 2022

Ioanna Exadaktylou says:
Irmarie will you stop the pill after 5 years.? Here in Greece they insist on me taking it for 5 more.i want to stop it.i m up to my limits


November 3, 2022

Nicole says:
Ioanna, I am from the US. I didn’t want to take tamoxifen 10 years so I asked if there was a test that would evaluate the differences between 5 and 10 years. There was , it was a fairly new test, one of those index tests. My oncologist had the tissue from my tumor so I was able to take it last year, 4 years after my lumpectomy . At first my insurance didn’t cover it, but later they did. I had to ask about this test, no one offered information about it before. Maybe you can ask about this test too. It is the reason I could confidently go off Tamoxifen after 5 years.


October 27, 2021

Christine J Breen says:
I am 70....complete hysterectomy at 22...own my own life coach practice. Still work 3 days a week. Had estrogen driven breast cancer....not brcc type, not hereditary....(no cancer either side.) Had lumpectomy. My test result was a 2....on the test that had to stay below 26 to avoid chemo. All test results were great. Am on Tamoxifin now, 6 weeks.....Constant brain fog, I can't concentrate to work, write, all the things I enjoy. Bloated and abdominal pain all the time. All the side effects seem so risky. Longevity in my family is well into the 90s. I have a positive attitude, am a spiritual person, love art, writing, walking, .....just feel non plus about everything....thick headed and sit far more than I used to. Do we know accurate stats on reoccurrence of cancer without Tamoxifin? Thank you. This is not how I want to live my life out, but I do want to live my life out❤️. Christine


April 13, 2022

Liz Adams says:
You raise an excellent point, Christine. I am 53 and live in New York. Not one of my Oncologists can give an answer regarding accurate stats on reoccurrence without Tamoxifen. I stopped taking a month ago and feel more like myself. Debilitating joint pain, mental confusion and general feeling of being unwell are all gone.


August 11, 2022

Karen Maisy says:
Liz, I went off tamoxifen a week ago after taking it for 2 1/2 years, wondering how long before it is out of my system totally. Diagnosed July 2019, widespread DCIS no lymph node involvement. Left side mastectomy with 2 failed reconstruction attempts. Implant failed due to the blue dye used to determine margins destroyed an area of skin (DCIS was very close to the skin). DIEP flap surgery failed 9 months later due to poor blood flow. That alone has left me a mental wreck. The tamoxifen has let me with brain fog, very emotional, and unable to lose the 20 lbs I put on after the last failed surgery. I was told the only reason to take tamoxifen is to reduce the remaining breast. No history of breast cancer in my family and at 65 I don't want to live like this anymore.


September 2, 2022

Tara says:
Christine, you indicate your oncotype score was 2. That seems to me like your chance for recurrence while taking tamoxifen would be something like two or three percent? So it would seem to me that if tamoxifen reduces the chance by 40% of a reoccurrence that it lessens your chance of a recurrence by around 2% tops? I in no way want to tell you what to do but you should really ask your doctor to try and pinpoint about what percentage you are at risk for reoccurrence without tamoxifen. It would seem to me the difference would be very small.


November 14, 2022

Trudy Madere says:
I have major regret! Started it at 49 years old. It was a gradual thing for me. After 3 years, noticed extreme fatigue, brain fog, body aches/pain, belly fat. I am now almost 57. So have been feeling this way for almost 5 years. Feels like I’m dying, had no idea-it was menopausal symptoms. I hate feeling like this 24/7. I try to do all the right things-exercise, eat right, balanced life.


September 29, 2022

Angie says:
I started tamoxifen February 2022. I have struggled. I can deal with the hot flashes and night sweats but the bone pain, can’t get out of bed, extreme mood swings, no sex life and I’m only 42. I stopped for a week. But I’m also worried if I should stop even though I feel better. I lost motivation and gained weight on the meds too. I was stage 2 IDC er+. My score was 19 so 6% chance return if I take the tamoxifen. Thoughts?


September 19, 2022

Kim says:
I was dx with dcis stage 0 a year ago. Had lumpectomy (which then showed a 1/3rd of 1mm micro invasive cancer stage 1) Had 20 rounds of radiation. Started on arimidex after that and stopped cause of vaginal dryness (painful). Now on tamoxifen. My onc put me on 10mg per day, but has since cut me down to 5mg because of a new study out of Europe that showed success with that dosage and for 3 years, not 5. He said he’s comfortable with doing the 5mg but not the 3 years because of something with the study being inconclusive on that? I also am debating whether to continue with this or not.... An insert that came on my last refill had results from a study on it. Study was women with dcis taking tamoxifen for 5 years. Out of every 1000 who took the placebo, 17 got bc. Out of every 1000 who took tamoxifen, 10 got bc. Study showed on avg, women w/dcis who took tamoxifen,lowered their chances of getting invasive cancer by 43%, from 17 in 1000, to 10 in 1000.


March 8, 2022

Virginia Rolley says:
I had stage 2 breast cancer along with it it invaded my lymph nodes on my left side. I could not take the side affects of tamoxifen and stopped. How risky is this for reoccurrence? I’m very confused.


April 11, 2022

Small lump found in mammogram. Never knew it was there. Size of a staple, also found a microscopic place in one lymph node. I've had both removed and 6 weeks of radiation. It's been a year now. I've been struggling with so many side effects with the tamoxifen. I'm 49 as of March 5th. The discomfort in my vaginal area I can't take. I've been a good sport about the hot flashes and night sweat, depression, lack sleep but this vaginal stuff is a whole new level. I've reached out to different doctors on my team and I honestly get no relief. I feel like I'm just not sick enough for anyone to really hear me. As of today I've not been on the tamoxifen 8 days.and I feel much better. This week will be my 5th time to stop. This time I stopped it on my own do to the vaginal discomfort. I just feel like I'm young to take it and feel so bad and I'm to take my chances. I do have a since of peace about it. Sending the power of understanding to your family members and doctors along with mine. God Bless


April 13, 2022

Wish I had taken it says:
I decided to risk it and didn't take tamoxifen for years. I was unlucky and had a reoccurrence. It's scary. I'm on arimedix and Ibrance now.


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