Tamoxifen 10mg vs 20mg

Posted by jeannie53 @jeannie53, Jun 25, 2019

I was on Anastrozole for 6 months my doctor switched me to Tamoxifen because of severe muscle pain. I was given 20mg of Tamoxifen is that the regular dosage every day. It also comes in 10mg. I saw a study that women were given 5mg each day by cutting the 10mg in half and was wondering if anyone has cut their dosage so it is better tolerated.

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jmab | @jmab | Mar 7 3:03pm

In reply to @marygb "@jmab I was also taking that lower dose . That medication makes me too nervous with..." + (show)

@marygb I hear you. My ILC was very early stage 1, no nodes, hopefully low risk. I didn't really want to take any blockers at all! So, the half-dose of Tam felt like a good compromise. And now, 2 months later I'm feeling more & more like my old self. Plus, honestly, the side effects from AI's (bone loss, joint pain, high cholesterol) scare me more than those with Tamoxifen! Which is why we each have to make our own choices. There's no right or wrong. But I believe it's valuable, sharing all of our stories. Best wishes to you!

marygb | @marygb | Mar 7 12:01pm

In reply to @jmab "@marygb I'm taking a half-dose (10mg) of Tamoxifen & doing ok. I'm 72 & my doctor..." + (show)

@jmab
I was also taking that lower dose . That medication makes me too nervous with the uterine cancer it can cause. It’s also not as effective in post menopausal women. That’s just my own personal thoughts on it. My oncologist did say it’s still a good medication even though it is not be as effective as an AI. I’m really surprised that they don’t have anything better with all the research and funding they receive. Maybe someday.

jmab | @jmab | Mar 7 11:16am

In reply to @marygb "@maryliz22503 I recently messaged my oncologist about giredestrant ( new drug) and she told me they..." + (show)

@marygb I'm taking a half-dose (10mg) of Tamoxifen & doing ok. I'm 72 & my doctor recommended Tam because of my bones.

jmab | @jmab | Mar 7 11:14am

In reply to @luckbme "I have been blaming tamoxifen for my terrible side effects. I had IDC, lumpectomy, 15 sessions..." + (show)

@luckbme it's so hard to say what exactly causes side effects when your body has gone through so much! For many of us, it's trial & error, trying to find the right balance. I'm 72, had a lumpectomy in October, 5-day radiation treatment & started January 1st with half-dose of Tamoxifen (10 mg). I'm doing ok. I've gained 5 pounds which I'm working on losing! Have you asked your oncologist for suggestions?

marygb | @marygb | Mar 7 10:55am

In reply to @maryliz22503 "@marygb Thank you for sharing this. What is the new med to be released this year..." + (show)

@maryliz22503
I recently messaged my oncologist about giredestrant ( new drug) and she told me they aren’t sure who that is going to be approved for yet. That was very disheartening to hear. I recently went back on Anastrazole in the hopes at years end that I can go on this new med but now I’m not so sure. I do have osteoporosis. I won’t take bone meds. I’m think about doing every other day because of my bones. I don’t feel like I have a good solution for my case. If I didn’t have osteoporosis I’d try sticking it out for the 5 yrs.

maryliz22503 | @maryliz22503 | Mar 7 10:02am

In reply to @marygb "@malebreastcancer47 I have a oncotype score of 22. My oncologist preferred I take an AI with..." + (show)

@marygb Thank you for sharing this. What is the new med to be released this year that is expected to be more effective? Can you give any more info that would help us identify and research it please?

melo777 | @melo777 | Mar 7 1:46am

🙏 Hi, This is my third cancer medication I’m supposed to start, I decided to do some research after so many reactions. I started back on Exemestane 25 mgs, more restlessness, no sleep, hot flashes. New Dr. prescribed Tamoxifen20 mgs. Don’t know what to do except go back to my first Dr. explain just this😢Horrible side affects

Arvind Natarajan | @malebreastcancer47 | Jan 8 11:01pm

I had stage 1 breast cancer. After recovery from surgery, 8 weeks later, I started on chemo. 4 infusions over 12 weeks. After 12 weeks, due to how I was feeling, I did not start Tamoxifen. Mayo said ok to waiting 1 year. I recovered from chemo effects, muscle loss, stamina, I had shortness of breath. I needed my body to heal as much as possible. 1 yr later, I started on Tamoxifen at 20 mg. The side effects was harsh and after 1 yr, Mayo oncology reduced to 10 mg.
Now I am finally feeling more normal. Able to work, sleep and do activities with minimal menopause effects.

If you have side effects, ask your doctor if you can pause the Tamoxifen until you have recovered from radiation.

luckbme | @luckbme | Jan 8 8:15pm

I have been blaming tamoxifen for my terrible side effects. I had IDC, lumpectomy, 15 sessions of radiation and all went very well. I felt good, actually. Then started tamoxifen and took for 10 weeks before I realized I could not live with those side effects and quit taking mid-April. Although the side effects are dwindling now, January 8, 2026, but still have some every day for a few hours, I'm wondering if the radiation caused the side effects. I started the tamoxifen immediately after the radiation, so it's hard to say. The tamoxifen, 10mg, has half life of 50 hours. Something is not adding up. Anyone?

ritalu | @ritalu | Jan 5 11:14am

I am taking 5 mg of tamoxifen daily. I have a friend who is taking 10 mg every other day. She does not feel any side affects. With the 5 mg, I feel fatigue and need to rest for about 20 minutes after taking the dosage. I had stage 0 DCIS - two lumpectomies - surgeries (second surgery 6 mos. after radiation) This might contribute to the fatigue.