Tons of testing showing up last few years. One thing on the HRT+ crowd is that they have money, care about their health and monitor. Some of the bulk of first reports on 1) eq lowering E2 2) primo lowering E2 3) primo hitting HDL even at moderate doses.
I have copious bloods back 15ish years (used peds on/off since 1990s). I can confirm 1-3 above on me. Exception is I haven't run primo under 600mg weekly (stellar bloods except HDL hit is near the same as 350mg of tren and 50mg Ed winstrol in a stack) so I don't know how low I can go before HDL hit shows. Primo lowers E2 some like 50% on 500 test 600 primo - leaves me at or just above top of normal male range. Equipoise, per above testing, is my E2 doom.
Like I said, individual as to impact and severity. Going theory is that E2 hit is caused by metabolites of these compounds.
Basically what we know and surmise now
https://thinksteroids.com/articles/primobolan-equipoise-crashed-my-e2-help/