Timing of HRT, anastrozole - taking day or night?

I found that taking it in the morning was best. It caused me insomnia, so morning was a no brainer for me.

I take at night as makes you tired

After dinner. Along with other supplements for hair loss (minoxidil) and joint pain (glucosamine). I was already taking calcium for bone loss. At bedtime I take melatonin for hot flashes. The combo is working, thank goodness. 🤞

I started taking it in AM but the hot flashes were horrible all day - did this for almost a year. So at my appt when we talked about side effects I was having - I said I hate them all but right now the hot flashes were the worst - so it was suggested to take it at night (yes night sweats but a tower fan on low helps immensely!! I've been taking it PM for almost 3 years now and it has really helped - I may get an occasional one now and then but nothing like before. So I can check that off the list of side effects I have on anastrozole as it's manageable now.

@wendysiegler
My oncologist prescribed Prolia when I was just starting anastrozole and with only a hint of Osteopenia.

One six month dose was all I could tolerate. The aches and pains were terrible but the mental side effects were too much. Changed oncologists and she agreed I didn’t need it as I wasn’t even on the scale of bone loss.

Please do your own research on Prolia. It isn’t something to introduce in your body without knowing what it can do to you.

Hi @jsparkle42,

I combined your discussion with an existing discussion titled:

"Timing of HRT, anastrozole - taking day or night?"
- https://connect.mayoclinic.org/discussion/timing-of-hrt-anastrozole-taking-day-or-night/

Here, members have discussed how they take their anastrozole (am or pm) and how it has worked best for them.

@kimogi57
I started taking my anastrozole every other morning about two weeks ago. Began it once daily about 2 years, 3 mo ago. Side effects were building so I stared every other day rather than stop. I have read they have clinical trials now to see if a lower dose than 1 mg every day would be better.
Speaking for myself, I do feel better!

My onco score was 10% without and 3% with AI. Finding a different oncologist now and will certainly tell my new doctor soon. Difficult decissions!

I started on Anastrozole first of April. My oncologist told me to take it at night. So far the only side effect I have is my thumb joint is very sore, and probably won’t go away until I am done with my treatment. Hopefully no more side effects.

Started taking letrozole last April 2025. Some hot sweats periodically and hair thinning at first which has gotten better. Something joints but I also have some arthritis so it it hard to tell what is causing what. I take it at night on my oncologists recommendation. It has increased my LDLs so now on a statin since oncology cardiologist says my diet and exercise can’t control it alone and my red yeast rice wasn’t doing it.