BTW, just thought of it. Tren does not easily aromatize - so, in general, AT MODERATE DOSES, it should not have that a progesteronic effect. but, AT HIGH DOSES, IT DOES START TO GIVE progesteronic side effects.
Remember, all 19-nortestosterone derivatives has to some degree progesteronic effects. It just depends on how easily the component aromatizes. These derivatives all attach to progesterone receptors and this is how they have a growth effect, by some unknown way they increase HGH secretion.
The progesterone only starts playing a role in gynae, the moment the compound aromatizes to estrogen or when the testosterone dosage stacked with it starts to aromatize - then this leads to havoc. This is why Nolva with 19-norteststerone derivatives in general don't go well as a combination, but Parlodel or Dostinex does.
Knowledge is power!