A Tale of Two Tamoxifens – a case study

*2016 update: I wrote this post in early 2015 while figuring out which brand of Tamoxifen worked best for me. I have since also adjusted my dose from 20mg, to 10mg. 

Clouds moving in- darkening the river sky scape.
Sun and clear skies create a wildly different view on things.
Sun and clear skies create a wildly different view on things.

The first thing I do each morning is to push back the curtain and look out at the landscape.  Morning meditation is spent observing the light and soaking up bird song through the open window. (BTW Red wing black birds are back in the chorus.) Saturday morning there was a sharp line of light along the north shore the Columbia River. It emphasized the  contrast between the dark mountains of Washington and the lighter blue of the river. The cottonwood trees on Alderbrook beach captured their share of the golden glow too, and for a fleeting moment were alight. Then the clouds shifted, and a tiny squall washed across the landscape. The palette turned to grey, as a mist closed in- until the cottonwoods became a darkness silhouetted against the grey sky.  An hour or so later, inspired by a sun break, Joe and I enjoyed a marvelous walk. While we were out another squall came through soaking us, and then the sun reemerged to warm us before we reached home.

Red Alder catkins during a sun brake in March 2014
Red Alder catkins highlighted by morning sun in March 2014
Red alder cones against a grey sky mid walk Saturday.
Red alder cones against a grey sky mid walk Saturday.

The difference that light makes is amazing- the landscape oscillates between glorious and dreary with the speed of the wind.  In noticing the light Saturday, I realized that it perfectly reflects the feelings within my body-mind while under the influence of the two different brands of Tamoxifen that I have been taking.

“It was the best of times, it was the worst of times….”                                                                                                Charles Dickens

In January the Pharmacist gave me the heads up that the brand of Tamoxifen he had been dispensing to me since July was unavailable, and that I would be receiving a different brand. “Don’t worry, they both contain the same amount of the active drug, it will be just as effective.” he said. His words brought to mind something I read last summer, while educating myself about Tamoxifen. I remembered reading on a UK breast cancer forum a thread in which the gals expressed some very strong opinions on the different side effects brand by brand.  I decided that I needed to be on the alert for any notable changes in myself, and told the pharmacist I would let him know about anything I experienced.

Chemical Structure of Tamoxifen C26H29NO
Chemical Structure of Tamoxifen: C26H29NO

Right away the most noticeable thing was a marked upturn in the frequency and intensity of my hot flashes. As I had just finished my last dose of Herceptin in December, I wasn’t sure how much to attribute to the change in Tamoxifen brands.  So when I called in February’s prescription I asked to return to the original brand. Within days I noticed that while the hot flashes had slowed, the painful neuropathy on the bottom of my feet, and overall joint pain- which I had attributed to the Herceptin- were back. My mood was definitely descending.

“Whoa, maybe there is a difference in the brands.” I thought.  I needed more data.  So after talking to Dr. Metro, who incidentally was a bio chemist prior to becoming a Naturopath and TCM herbalist, I knew to check out the inactive ingredients list of the two brands. I had saved a pill from the January bottle, and so was able to look up the numbers on both pills to discover what I could.

EXHIBIT A: TEVA brand – taken July 2014-December 2014 and February 2015

93 782 (Tamoxifen 20 mg) manufacturer: Teva Pharmeceuticals USA Inactive ingredients: croscarmellose sodium hypromellose 2910 (5 mPa.s) lactose monohydrate magnesium stearate polyethylene glycole 400 povidone k30 corn starch titanium dioxide
EXHIBIT A: 93 782 (Tamoxifen 20 mg)
Manufacturer: Teva Pharmeceuticals USA
Inactive ingredients:
croscarmellose sodium
hypromellose 2910 (5 mPa.s)
lactose monohydrate
magnesium stearate
polyethylene glycole 400
povidone k30
corn starch
titanium dioxide

 EXHIBIT B: MYLAN brand – taken January 2015 and March 2015

M 274 (Tamoxifen 20 mg) Manufacturer: Mylan Pharmaceuticals Inactive ingredients: lactos anhydrous silicone dioxide crospovidone magnesium stearate microcrystalline cellulose sodium lauryl sulfate
EXHIBIT B: M 274 (Tamoxifen 20 mg)
Manufacturer: Mylan Pharmaceuticals
Inactive ingredients:
lactos anhydrous
silicone dioxide
magnesium stearate
microcrystalline cellulose
sodium lauryl sulfate

To be completely honest I really don’t know what any of those things are.  However it is interesting to note that it takes 3 pills to make up a gram- each pill has 20mg of Active Ingredient, and so each pill has 313.33 mg of Inactive Ingredients. The active ingredient (C26H29NO) constitutes only 6% of the pill.  “Mmmm, perhaps my body is responding to the 94% of so called inactive components?” Or perhaps it is all in my head. So when March rolled around I requested to return to EXHIBIT B- what I now knew to be Mylan brand to observe possible differences.

It was like the sun coming out on the river. Within days no more joint pain, better mood, no more painful morning feet- and a tremendous upswing in the hot flash solar flares.

Ship during a squall on Saturday
Ship during a squall on Saturday
Ship with sun on Saturday
Ship with sun on Saturday

I also needed to involve a few key witnesses to substantiate my subjective experience. I interviewed my children. There was no doubt in their minds that there was a noticeable difference between “weepy-hopeless-unmotivated Mama, vs Happy-art making-serious house tidying up Mama.” And yes they had noticed a steady decline in the Happy Mama mojo last year- and a return to Happy Mama in January followed by Weepy Mama in February and more Happy Mama in March. They also expressed a clear preference for the happy version of me.

“Sometimes depression is contagious, that’s the worst kind.”                                                                                              Martin Daire

MMmm. Looking back at the second half of 2014 I had been on the look out for mood disturbance, a known side effect of Tamoxifen itself, but the change was subtle at first and easy to overlook. It made sense that I would have trouble maintaining a positive mindset while adjusting to the loss of  breast and lymph nodes. Not to mention the advancement of cancering in more than one friend- and their subsequent deaths.  Also the Herceptin treatments definitely were still a big factor in the grey out of my mood.  It is easy to overlook things when there are so many contributing factors to every aspect of our health and wellbeing. It is humbling to recognize the impact of less than 1/3 of a gram of “inert” substances on my ability to maintain equilibrium.  And even more sobering to think that my drug induced drear was contagious to those I love.


While doing a bit of research for this post I went back and read the posts on the UK breast cancer forum about Tamoxifen- different folks had preferences for both brands. There was not a clear consensus. I am more convinced than ever that each person is different. My conclusion after my tiny case study is that Mylan Brand is more compatible with my body. I will gladly choose to surf the hot flashes (Kundalini Rising) in order to skip the depression and joint pain if given the option. For right now my insurance is willing to pay for either,

I am taking only this one Big Pharma drug. When I think of the variety of prescriptions many people are on, I wonder what effects they might be experiencing that are due entirely to the “Inactive” content of their daily dose.   Our bodies are so incredibly sensitive- it is amazing to me how such tiny amounts of certain things can so profoundly effect the balance.

This morning a swirl of gulls was passing in and out of a swath of light – becoming bright white against the dark sky. My thought was that they were made of living light, and that so are we.  When the sun break closed, they became nearly invisible again.  The difference between being the best of times, or being the worst of times is sometimes something as small and ephemeral as a sun beam. Near impossible to pin down- but profoundly impactful. Taking time to observe, and to trust my inner sense is definitely on the road to happy for me.

Salmon Berry vines are blooming in the shadows.
Salmon Berry vines are blooming in the shadows.


7 Comments Add yours

  1. thesmallc says:

    This is very interesting. I did a little bit of research too after I was given the Mylan version. I was willing to give it a try, but after reading about other patients’ experiences I decided to stick with the devil I knew. I was only on Mylan for over a week and noticed one side effect: I felt dizzy. Someone had shared an article with me from another blogger who actually fainted when she took the different brand. So this is what prompted me to go back to Teva. But I am not happy with Teva either — mood swings and terrible dryness. I do have moments when I wonder if taking the Mylan would have been better for me. The ‘good news’ is that I still have 5 years left on this medication so there’s plenty of time for me to change my mind. Glad you found a brand that worked for you. xx

    1. Iridacea says:

      Ironically for the month of May I am taking a holiday from Tamoxifen, to try to determine which issues I am having are side effects and what is something else. My Doctor agreed to switch me to 10mg dose until my next appointment with him to see if the issues I am having are better. The mood stuff was so bad on the original brand that I am willing to put up with what the Mylan does provide, namely hot flashes, leg cramps, dry eyeballs, migraines, lowered libido… Oh joy any way you slice it.

  2. Theresa says:

    Thank you for sharing- have not started my tamoxifen yet but will go into it with more wisdom!

    1. Iridacea says:

      Best wishes to you-

  3. Stina says:

    I’ve on my forth month of Tamoxifen which has the cleaner non active substances of the two brands I’ve been offered. In which I refused to take the other one after studying the ingredients within.

    Rumour has is Mylan has been stopped in my country. Don’t know why but will continue with them for yet another 60 days.

    1. Iridacea says:

      It was very interesting to me how much I was effected by those so called inactive ingredients. Best of luck with your cancering travels.
      Xo iris

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