How long for PSA to drop when starting ADT?

[CatNinja]

Hi everyone. My partner was at 1.17 post RP (GS 4+5=9, SVI, N+). PSMA scan indicated some diffuse PCa remaining in the pelvic area (not enough to biopsy) and a possible met to the right rear hip bone. He started firmagon a month ago and had his first Lupron shot Friday. Repeat PSA from Friday before the shot was 0.4. How long does it take to drop to undetectable, if it's going to?

Thanks!

[Tall_Allen]

There's no set time. You just have to monitor.

[IrishDude]

I got my PSA tested after 6 weeks on Lupron and it was undetectable at that point. Apparently your mileage may vary,