It is outrageous that an editor felt it necessary to "americanise" my question. I asked it correctly in ENGLISH. Oestrogen and sulPHated are CORRECT

Sulfated estogens are inactiveand deconjunctionis needed for active estogens .

Thank you Mordecai, this is indeed the accepted view, what I was asking about is whether there are any data to the contrary. It is worth noting that some widely accepted views turn out not to be quite as correct as previously thought!

Hi Paul -- good question, and I don't know the answer.  I would be interested in getting references that show that sulfated estrogen(s) (actually, other hormones too, as well as PHAHs) are NOT active.  It is certainly the assumption...

Hi Paul! In PMID: 12538622 (2003, Endocrinology, Wood et al) they conclude "that sulfoconjugated estrogens augment fetal HPA axis activity and that they can cross the fetal blood-brain barrier. We propose that in late gestation the large circulating pool of sulfoconjugated estrogen is a biologically important source of active hormone that might play a role in the timing of parturition in sheep." Best, Margareta

Dear Paul,

I only know the biblical answer, which Motti mentioned, but since we have a number of systems in place to test this idea, maybe we should do just that. I'll get in touch. BW Richard.

Estrogens act mainly by binding to estrogen receptors, ERs. Sulfated estrogens are known unable to bind to ERs. So estrogen sulfates are inactive forms of estrogens. You can't test this in vivo, because sulfatase in vivo will de-sulfate estrogen sulfates to regenerate active estrogens. So, if you feed estrogen sulfates, it will generate active estrogens in vivo. This should not be just an assumption, because polar estrogen sulfates will not bind to ERs and activate them. Estrogen sulfotransferase (SULT1E1) is responsible for in vivo sulfation of estrogens.