Has tamoxifen stopped your periods?

I’ve only been on tamoxifen for a month but had no period when I was expecting it a week or so ago. I’ve not had chemo, but was doing rads from 8th to 28th September.
Does this mean I won’t get periods when on tamoxifen? Or is it a one off?
What are your experiences? I’d be really interested to know how we are all affected by tamoxifen.

I had to have my wonderful mirena coil taken out(period free for 5 years with it) but my onc wanted it out as I was 100% ER and PR receptive. Went straight onto tamoxifen before rads and after a couple of months being irregular my periods have just settled back down to being regular as clockwork, I’m 46 now and would be more than happy for them to disappear ! You could always mention it to your gp or bcn if you are worried. Good luck.

Sandra x

Me too - had to have my beloved Mirena coil taken out. That has had such knock-on effects in terms of the monthly menace and contraception choices. My hubby is investigating having a vasectomy - would never have thought I’d see the day!
I’m happy not having periods,believe me, but don’t want to get too used to it and then they arrive back again!!
Thanks for your post Sandra,

i had my mirena taken out, too. My C was er+ as well…

i did have chemo (fec) but my periods havent come back . My onc said that they can return up to 2-3 years after chemo/taking tamox. Im 43. Not had a period since Nov '09 when i started the fec.

I had to have my Mirena coil removed too since my BC was ER+ and PR+, I was so upset, the Mirena suited me so well! I’ve had it replaced with a conventional coil. Not had a period since 2000 due to Mirena coils, been on Tamoxifen for 2 months and no sign of a period, but I’m 51. In fact the Mirena has proved to be a bit of a buggeration factor because one of the first things the medical people always want to know is whether I’m still on my way through the menopause or have reached the end of it, and thanks to the Mirena I’ve no idea. Further complicated by having started HRT last year, which of course has now been stopped. Blood tests have proved inconclusive, so I’m now on Tamoxifen and Zoladex for two years. The conclusion seems to be make sure you aren’t diagnosed with BC around the age of 50, particularly if you have a Mirena coil!

Sounds similar to me CheshireCheese. I’d had Mirenas for 11 years, and then got diagnosed with DCIS (ER+) in May at 49. No idea where I am in relation to menopause at all. I didn’t fancy a conventional coil in case I got bad stomach pains with it, and I was fed up with having things done to me. How are you getting on with yours?

Hi Susie
I’m finding it no trouble at all. Having it put in felt exactly the same as the Mirena, mild discomfort, but then it was fine. I believe the problem with a conventional coil when you’re younger is that it can cause heavy periods - exactly the problem I was trying to solve with the Mirena - but now I’m so close to being over the hill in fertility terms, that is not a problem!
Sarah x

Hi cheshirecheese,

I agree about the age of diagnosis being a pain when it comes to the menopause questions! I am 53 and keep being asked if I have had my menopause - I say ‘no’ as I am still having periods - all be it less regular, longer and heavier!
Been on Tamoxifen for nearly a month now and no period but lots of low tummy pains. Have to wait and see, I guess. I suppose that the Tamoxifen may just be the trigger to the menopause, although my consultant said they don’t understand how it works with the menopause and why it is different for different women!

Hi Ladies!

I am 48 years old and was diagnosed nearly 4 years ago. I too had a mirena coil which I was advised to have removed (had it for 8 years). I now have an ordinary coil. I didn’t have chemo - lump out, nodes tested, radio and tamoxifen. I’ve been on tamoxifen for 3 and a half years and have regular very heavy periods with stomach cramps. My consultant said some women stop others don’t! Just my luck to have hot flushes, weight gain, bloating etc with tamoxifen and still heavy periods!!
Take care ladies!

I am my 4th month of tamoxifen, no chemo or rads. 1st month period 3 weeks late, 2nd month on time but lighter, last month a lot lighter. I was told before i started they may stop altogether.

Hi there, been on tamoxifen for 8 months. Used to be very regular but went 3 months with no period, then had a mega-heavy one. Next one was 6 wks later, not so bad, then a month later had the third, a bit lighter still. Since july, not a sausage so I’m girding my loins for another explosion anytime soon!

Just want to mention that Tamoxifen is not an aromatase inhibiter like Letrozole. Tamoxifen does not stop the production of Oestrogen, it simply disrupts the ability of cancer cells to absorb oestrogen - so it’s difficult to see how it could influence menstruation. Chemo can stop menstruation though.

Although tamoxifen doesn’t stop oestrogen but as Lemongrass says disrupts it’s ability for cells to absorb oestrogen, on the medication leaflet as side effects it says ‘it may cause mensstrual disorders including unusual or no regular periods or changes to the lining of the uterus.’ Both my onc and consultant said three and a half years ago when I started on it, that it was more common for periods to stop on tamoxifen than for them to carry on. Unfortunately I have not been lucky enough for them to stop which would have been one slight bonus of taking the tamoxifen!!
Take care
Shorty 2

Mine have been almost to the day since i was diagnosed last april. Chemo barely changed them and tamox hasnt stopped them either!

My ONC said she would be surprised if they continued after a year of tamox- that would be December…lets see!


Very interested in this. When I asked my onc what the plan/timeframe would be for me to be able to try for a family, he said that after I come off Zoladex (not for another 15 months yet), I have to stay on Tamoxifen until my periods return and then come off the Tamox to starting trying. I did whether Tamox stops your periods and he said no. We shall see… someone else will be my onc by the time it comes around (current one is leaving for a new job in Canada), so I shall ask again nearer the time.

Interesting thread!
My periods stopped after the third FEC, back in February.
I then had one a fortnight ago, heavy , but not totally unbearable.
Not sure what to expect now, maybe they are on their way back, i really don’t know!

My periods stopped in april on my second A/C JUST STARTED TAKIN TAMOXIFEN bout 10days ago i am 44 my onc isnt sure weather my periods will return at all have to do blood test to see if im pre-post menapausal heres hoping they dont not sure im that lucky


Mine stopped after/during my first cycle of Epi at the age of 41 and have never returned and i have been on tamoxifen now for over two years.


Hi there,
I’m 36, been on tam for over a year now and my periods went back to normal after having my mirena taken out. Copper coil fitted, and heavy and as regular as clockwork with the added bonus of hellish pmt. No signs of mine stopping! Unfortunately. Interesting to read how different everyone is.

My periods stopped approx 6 months after starting Tamoxifen :slight_smile:

Incidentally I tried the Mirena Coil 8 years ago due to having very heavy periods and it didnt help at all :frowning: