To Pre-Menopausal Women: Period after taking Tamoxifen

I started taking Tamoxifen in October 2012.  Had my last period October 31st, then nothing for a year and 4 months until February of this year, 2014.  My oncologist said that it was no big deal.  (Easy for him to say!) He said to worry if the period doesn't stop.  It was extremely heavy, but it stopped after a week.  It's been almost 2 months and nothing since then.  I'm 43, and had chemo and radiation in 2012.  Hope that helps some.

I started tamoxifen in September 2009 ( age 48, premenopausal). My periods were fairly normal, about six weeks in between. I saw my gynecologist every year for an ultrasound of the uterus, because of the side effects of tamoxifen. Apart from a polyp that gave me extreme bleeding ( had to be taken out), no issues. In January 2014 I was diagnosed with breast cancer. Last period at that time was September 2013 ( before that June 2013, March 2013). In January I had a bilateral mastectomy and stopped taking tamoxifen. I had a period at March 2014, and started bleeding again at March 29th. Haven't stopped since, so I have an appointment for an ultrasound and an appointment with my gynecologist. 

I am premenopausal (47).  My periods have remained regular since I started tamox at the beginning of Jan.  My onc said they should be normal until my body goes through menopause.  I did not have chemo.  I did just have a hysteroscopy/D and C because of abnormally thick uterine lining and it was all normal.  My OB will be checking me via ultrasound every year to make sure the uterine lining is not thickening due to tamox. 

hiva---my oncologist told me 25% will continue to get normal periods, 50% will have irregular periods, and 25% will stop altogether, while taking tamoxifen. Mine becam very light and very irregular.

anne

I had a period 1 year after chemo while on tamox...my onc then shut me down using zoladex.  I did those for 10 months and then stopped...got my period back again after 5 months and then resumed zoladex. My friend on tamox gets her periods every 2 months or so and they are lighter then before

My periods returned after 6 months of Tamo - had 5 periods or so and now nothing for 4 months! At the time it returned I too was quite concerned and started "researching" the subject. I don't have the studies here but I recall it COULD be but not necesseraly is a bad prognostic sign if periods return. There were some indications that having many menopausal symptoms during tamo is a good sign (hot flashes, etc and I guess no periods). I was told that I should take 30-40 mg Tamo if my periods continued. Reduced breast density is a good prognostic sign.

hlya: No, I didn't have a fibroid.  

My onc said I should be getting periods until my regular menopause time (my mom was also older so it could be a while).  She also said I may start experiencing heavier/longer periods but so far that hasn't happened. I've been doing the happy dance that I haven't experienced tamox symptoms.  Now you guys are making me nervous!  Here's hoping for hot flashes?!  

I've been on Tamoxifen since January.  Had my period that month but haven't had it since.  I do get more cramping now and more often.  Does anyone else get that?  My hot flashes so far haven't been that bad.  I hope it stays that way  :-)

my only side effect is the mild crampiness also.  Mine feels more like ovary crampiness like what I used to get at ovulation time, but still no period since I started taking tam.  

I just began my Tamoxifen treatment plan so I will have to wait and see if there is a change in my periods.  I'm 47 and have always been and still am like "clock work."  I actually saw my GYN on the 4th day after the start of Tamoxifen.  She told me that it may not affect my periods at all since I am still so regular that I will probably remain the same.  The patients she sees that are in my age range that have to begin taking Tamoxifen have usually gone through chemo first which will stop the periods and throw them into menopause.  The ones like me who are still very regular in their cycle  and the treatment is just Tamoxifen and no chemo usually never see a change until it is the natural time for their body to go through menopause.   At least that is what I was told.  My GYN did ask that I begin charting exactly what day I start and how many days the period last and how heavy.  She said to call if the periods become extremely heavy or was still happening by day 10.

Finished chemo a month ago, and my period is back already (didn't have one through 5 months of chemo).  Will start tamoxifen after rads.

OK ladies, I am 56 and still primenopausal..( Blood test.)...Taking Tamoxifen for 2,5 years...They told me, if you see some blood, it is OK, but if it is MUCH, it is not OK...I had it after intercourse... this is one of uterus cancer signs... ultrasound next week... Scared of results and dreadful about endometrial biopsy ( had one, could not finish) My question is: how much is much? I had about a spoon...I hope it will be OK...