Took about 2 weeks for me.

I am on Eligard/Lupron and didn’t have hot flashes for one month then they came on regularly, mostly at night so sleep was and still is interrupted. I bought a neck fan that I lay next to me and grab it when the flashes start. It looks like a headset and can be worn around my neck during the day - has been very helpful and is rechargeable - brand is JisuLite. Good price point. My neighbor takes Lupron and Erleada and has never had hot flashes after 2 years so maybe you’ll get lucky! He did say, however, his doctor said it was really unusual not to have them. Take care and best to you.

Hot flashes a few days later but very very mild two weeks into meds..so far going well

An answer and tips if you do get hot flashes.

I had really bad hot flashes after a couple of weeks. I would wake up at night and the sheet would be soaked under me because I’ve been sweating so much. After a year, my oncologist prescribed depo-provera, Every three months, and the hot flashes became much milder and less frequent. Then I started Zytiga And the hot flashes came back, Not quite as intense.

There are other drugs that can stop hot flashes like depo-provera which I used it for four years without any problems. Other Hormones can do it.

I now wear a Wave 2 from embrlabs.com. The device has two buttons, and I have one set for hot flashes during the day and one set for all night.