Quote Originally Posted by BrotherIron View Post
Not at all. AI are designed to inhibit estrogen not progesterone. That is exactly what dostinex, bromo, etc are designed for. You get gyno from Tren or Deca and an AI, like letro, a-sin, or a-dex will do nothing for you.

If your estro is kept in check, proges is less likely to arise. Those drugs (caber, dost, prami) are more of anti depressants. I would have them on hand in case of someone being prone to it.

Not mine, but a good read none the less.


I would like to clear up a few misconceptions about progesterone and gynecomastia.

Their is absolutely no steroid that aromatizes into progesterone. The reason for this is that progesteron does not have an aromatic A ring. So toss that myth out the window. Tren? Deca? Sorry but it just doesn't happen.

Now Tren and Deca bind pretty well to the PR. They are progestins in their own right without undergoing any structural changes, but their affinity is MUCH weaker than progesterone itself. Even more so when nandrolone is reduced by 5-alpha reductase into DHN. Their is a small chance of progestogenic activity that could aid in manifesting a mass in the mammry IF estrogen is present in supraphysiological amounts, without proper ratio to testosterone but I have never see a documented case of progestogenic gynecomastia. The reason for this is that the PR has two isoforms. The PR-A and PR-B. PR-B mediates stimulatory effects of progestins; PR-A which is bound with progestins or anti-progestins inhibits PR-B, and PR-A is ***inant,. The response to progesterone is determined by the relative expression of the two isoforms.

There is a direct relationship between the PR isoforms and steroid concentrations an this direct relationship suggests high progesterone concentrations, but this will induce the expression of PR-A, which represses transcription of PR-B, which in turn supresses PR function and progestin effect
With initial administration of nandrolone or it's dirivitives, I could see an expression of PR-B but a rapid rise in PR-A will ultimately supress the function of the PR. IMO, you would need a high ratio of the two before concerns, and this is a bit more of a possiblity with the begining of administration. In this time of vulnerability, rest assured in aromatase inhibitors as progesterone is an E2 agonist so the utilization of an AI will help. I personally don't think the concern is warranted though

Their are 4 combinations of hormones that cause gyno- Estrogen, Progesterone, Prolactin, and IGF. Nandrolone is a weak progestin, which agonizes the PRL, it also raises IGF. Progesterone induced gyno is not really of a concern given binding affinity to the PR and the mechanism of the two isoforms. The production of prolactin is a deffinate risk. Not only can it be an inductor for gyno along side estrogen, IGF, and pogesterone; this chance is increased as prolactn lowers testosterone. So you need to make sure to take proper precautions to not only keep estrogen in check, but prolactin as well.

Also, basically from what I've read on the matter, prolactin or progesterone will not cause gyno unless there is excess estrogen that has been aromatized in the body and already beginning the stages of gyno. It just adds on to the problem and brings with it lactation. Having said that, if you are on nonaromatizing compounds along with tren, you should not get gyno. If you are on winny (and anti-progestagenic) you will not get gyno. If you are on aromatizing compounds and you supplement with anti-e's and AI, you should not get gyno because your estrogen level will be in check therefore not causing excess estrogen for the progesterone to team up with. Its all starting to make a little more sense to me now. If any of you have any conflicting or additional information to this topic, please post it. I am in the process of adding the Tren E back in my cycle as soon as I feel comfortable that I have my gyno in check.