[spanky (aka Lola)]

Making a comment to put myself in the notification loop-I'm interested in that question as well. 

I'm assuming from my reading that by invalidate, you mean render useless... I'm assuming from my reading elsewhere that estrogens will lower PSA levels as a good thing. I did find this list of things that affect PSA, from a urology clinic

https://www.advancedurology.net/blog/10-...psa-levels

that suggest if you're taking anything that could raise or lower PSA levels, to let your provider know when getting the test done, presumably so they can factor that in.

In my case I'm wanting to try some Bi-Est cream but wouldn't care to broadcast that to my provider (as I wouldn't actually be transitioning and no one knows I wish to intentionally trigger breast growth) so I'm also very much interested in a rough estimate of time one should cease supplemental estrogens before getting a PSA done. Although I suppose the same could be said for most of what we might be taking here on Breast Nexum as either phytoestrogen or AAs.

I suppose the 'invalidness' comes from if someone unknowingly had prostate cancer but had lowered their PSA via the EV or supplements- which is a good thing- but might hide the presence of the cancer from the physician? 

That URL I provide gives various wait times before taking a PSA test for things that might temporarily increase your PSA level, but it really doesn't detail much of what to do other than inform the doctor of things you're doing that might lower it... I think in the absence of information I'd personally wait maybe a month or six weeks off everything, to be safe? Does that seem like enough time?