T Nation

Masteron as SERM


I'm curious as to whether under certain circumstances whether the use of masteron in a cycle would eliminate the use of arimidex during the cycle to combat the aromatization of other steroids into estrogen? And if so what sort of doses would need to be taken to do so?


It is I think very unlikely to be a selective estrogen receptor modulator but it likely has some anti-aromatase activity and may have some direct estrogen receptor antagonist activity.

I would view it this way: A cycle that otherwise would be a little past the edge with regard to estrogen if no anti-aromatase or SERM were used could well be brought back within an acceptable range for estrogen by inclusion of Masteron.

But for example -- and going for a more extreme example than necessary -- a gyno-sensitive person should not assume that he could take 1000 mg/week of testosterone ester without a SERM or anti-aromatase in the expectation that 200 mg/week of Masteron would cover him. I wouldn't expect it to do so.


Agreed. Mast should never be viewed as a replacement for a true SERM or AI. If you need one of those you better be taking them. However, if you understand where your limits and needs are you can dose for yourself appropriately. For instance, Im currently cruising at 500mg/wk test and 400mg/wk mast. I also use dbol before my training 40mg on days I train. Anyway, I do not actively use an AI or SERM with these doses. Mind you I do have both tamox and anastrozole in moderate supply if something were to happen. Quite frankly the doses Im running now are better for me than just a straight gram of test. Part of the reason Mast is sometimes referred to as a cutting product is no doubt because of its estrogen control properties.


You bring up an important point: another and very important way that it can be effective in reducing estrogenic effect in cycles is by substitution instead of addition.

In other words, while adding say 200 mg/week Masteron to a gram per week of testosterone won't make a really major difference with regard to possible estrogen issues, when the gram per week testosterone is instead compared to 600 mg/week testosterone ester plus 400 mg/week Masteron, now there is much more improvement with regard to estrogenic effect. The latter can quite likely be fine for an individual who would have found the testosterone-only cycle to be excessive with regards to estrogen.


That's way it's probably better to stack any AAS than simply use 1g of Test straight. Benefits add up while the side effects don't as much with multiple enhancers.

Bill, I think you experimented with the use of Masteron as a bridge. At low doses and by itself, you thought it might basically be non suppressive. Did you get any conclusion on this one?


I'm planning to do an LH test fairly shortly.

This will be on the perhaps-over-aggressive protocol of a total of 300 mg dromostanolone enanthate per week plus a total of 1500 IU HCG/week and a total of 2.5 mg/week letrozole.

I wouldn't be surprised if that is too much, but who knows, we will see.

My estimation actually had been of 200 mg/week Masteron as a top end for this purpose, but I wound up doing the 300.


Is the HCG necessary for the protocol? I understand the use of an A.I. if someone is coming off a cycle, but for bridges the "less drugs the better" is a great aim to shoot for IMO.

I guess the length would be 6-8 weeks? Starting 2 weeks after the last shot of a long ester?


No, another protocol would be Masteron-only, titrating the use where estradiol level remained low-normal, which also would indicate normal T production. An LH test would be more conclusive.

It might be the case that a testosterone test could be deceptive, as I don't know that Masteron may not falsely be picked up as being testosterone. (That happens with some steroids.)


I see. Estradiol and LH tests only. I hope your findings will be to your liking. It could very well be the new gold standard for bridges/post cycle!


I am really liking it. So if LH is being maintained in the normal range, I'll be quite happy.

Oh yeah, there's also 20 mg Dianabol 3x/week in my current "not really 'on'" protocol.

So if this is overdoing it, I won't be surprised, but who knows.

If it is overdoing it, I'll back down and find what level of use does still allow reasonable LH production while providing substantial benefit.


That's awesome of you to be trialing this theory in the flesh finally Bill.
Can't wait to hear how it pans out.
Good luck!


Thanks! :slight_smile:


Yeah substitution. I know Prisoner's test taper protocol he advocates using a 50-50 mix of test and mast for many of the above mentioned reasons


Masteron is not enough to use as estro/gyno protection alone for me.

I also require a very small amount of nolvadex (serm 1 tab 20mg split in two per week) to use with it to keep gyno away and estrogen is building up slowly over time for me, previously my mood was normal and all was good but now getting furthur on into the cycle i can feel mood swings creeping in and estrogen buildup happening over time.

There is a little more visible water retention even though most parts of my body look a lot leaner and some loss of libido over the last week.

I am using mast prop at 200mg/week. Will be increasing it substantially tomorrow actually.

Funny thing with the mast though is my nipples never get puffy while on it...but I still need the nolva for gyno. Intresting that.


200mg a week is quite a low dose to really see, feel and experience mast's benefits. I know you said you're increasing it substantially which should serve you well. 350-400mg/wk seems to be where most notice the effects.


The goal here is to find if and what level of Mast can be used without shutting down our natural hormones. If it can be done, it won't produce near the results as a full cycle but that's not the point.

It could be used as bridge, "stasis" before going off, a form of HRT, etc. Let's say it's 200mg. Well that's 200mn on top of what we'd produce, or at the very least, give some support after a cycle or between ones. I hope it does pan out!


Well that wasn't the OP's stated goal but your point can be addressed and it already was in Prisoner's test taper there. [From memory] I believe its 25mg a week additonal is non-suppressiveand 100mg a week is ok with the addition of a SERM


That was for Testosterone. I think Bill wants to experiment with Masteron as the dose might possibly be a lot higher. It remains to be seen but it could be pretty big when you think about it, probably even for HRT purposes.


True it was test. Not sure what pretty big is but I'd be surprised if someone could add more than 100mg of masteron without starting to shut down endogenous production.


I expect there's a start with any added androgen whatsoever.

However, it's possible to have absolute top end of normal free T levels while obviously still having quite good LH production: typically high midnormal or better.

So, particularly if there's the benefit of E2 levels being kept at the low end of normal, it's not unreasonable to expect that moderately supraphysiological androgen activity can coexist with at least low-normal LH production.