Periods

[Rorpethy]

I was only on mounjaro for 1 pen (5 does of 2.5ml) but it's messed with my periods quite badly. I had a nearly 2 weeks long period, then 2 weeks later, had another 2 week long period and spotting in between. Has anyone else had this? I've now been off mounjaro for nearly a month so it will be interesting to see if my periods go back to normal.

For me - If I have fast weight loss I often kick my body into a prolonged period - I'm talking weeks long. I think it's got something to do with losing fat, and the fat releases its stores of oestrogen, causing you to have a period. At least that is my thought on it.

I had similar, after being on for 5 months I then started having more frequent periods and spotting between. I’ve had some initial tests and am now being seen for a hysteroscopy due to thickened endometrium layer, no idea if it’s connected but I’m seeing many report period changes which is worrying me. Am still on the jabs and it’s been 9 months now.

I started Mounjaro in January while on HRT and contraceptive pill and not having had a period for ages (I’m 51). Within a few days of starting I started bleeding which after a two or three weeks became extremely heavy and has not stopped apart from having a course of Provera to stop it for a few days to enable examinations to take place. Have seen my GP who referred me for a scan which took place last week, nothing untoward reported so my GP does think it’s just a side effect of the jab.

I have a Mirena coil which means that I don't usually have periods at all, but I have had two in the ten months that I have been on MJ. As @HappyShortFuse says I think it's quite a common phenomenon and is linked to the storage of oestrogen in fat cells.

Mine has been drastically the other way. I’ve got insulin resistant PCOS and since I started my periods over 25 years ago have had one or two a year. It’s like a blood bath but as it was so rare I just accepted life that way.
Since I started MJ back in October I’ve had a period every month from November onwards and pretty consistently at the same sort of time every month. I’ve lost 4 stone and it seems to have kickstarted my body into finally doing what it should have been doing my whole life. They are much lighter and way less mass clots too.

I started Mounjaro in July, from December I started to have a period every two weeks with bleeding in between. I went to doc and had a lot of tests including hysteroscopy as they put down suspected endometrial cancer - thankfully nothing was found. I firmly believe it was the Mounjaro.

Just came across this thread. I’m on HRT conti and since starting mounjaro 2 months ago have had recently had withdrawal bleeds every couple of weeks. Definitely think it’s that. Have read that it affects oestrogen levels so makes sense hormones are out of balance.

Im W3D7 with MJ, i had my last period a week ago and ive just been to the toilet because i am very lightly bleeding…
i have been like a clockwork all my life (48 now)
not sure whether to make an appointment straight away to the GP or wait and see how it develops … it does freaks me out a bit…
im happy to lose slowly, i take the jab every 9 days so i am very worried now!

@Rorpethy did your periods come back to a normal cycle?
was it the GP who told you to stop?
have you started MJ again? Was it linked to MJ?
so many questions! Id be grateful for your insights

Sorry for the delay in replying I have only just logged back into Mumsnet after a long time.

My periods went back to normal after coming off Mj. I went to the doctor and had tests done just incase it wasn't the Mj but everything was completely normal so I firmly believe Mj was to blame.

I started Mj again yesterday after nearly a year off so it will be interesting to see if the same thing happens again.

I’ve had almost the opposite my periods are still regular but pre MJ I was having horrific peri menopause bleeds which were so heavy they were almost uncontrollable- they are now much lighter and a bit shorter - I’ve been on WLI since beginning of April.

I was on the combined pill until December 2024, which produced "pill periods" when you have a break between packets. I stopped taking it aged 49 as I'd have to stop at 50 anyway and I wanted to see if my periods had stopped naturally. Had no periods, started taking Mounjaro in March and still nothing. It's a relief, long may it continue!