My Salvage Tx was IMRT radiation 37 txs together with 4 mos ADT. I took Orgovyx.
Side effects (SEs) for me were moderate but manageable.
Difficult to differentiate between causes.
Radiation Proctitis was a SE for me, and it cleared 2 - 4 wks post radiation.
ADT caused fatigue, minor hot flushes, mental fog. I describe it as all the issues of a 73 yr old exacerbated.
All SEs abated substantially about 4 mos after ADT completed, except some residual mid afternoon fatigue, when my recliner looks particularly inviting.
Not an expert, but I think that Lupron comes in 1, 3 & 6 mos injections.
SPPORT trial supports 4 - 6 month short term ADT together with radiation to whole pelvic region (WPRT).
Good news is that my 2 PSA tests following salvage tx have been undetectable.
Short answer to the Q initially posted: Too long!
Good luck with your treatments.