How did the myth start that Primobolan was an AI?

[DonTesto]

It is not a myth. Primo has a metabolite that inhibits E2 conversion. However, the pharmacokinetics of the mechanisms of actions are not 100% understood. But honestly we do not need to, it is pretty straight forward, some people get more e2 inhibition from it than others, I'm sure some get virtually none. Certainly does not act like a SERM, Mast does. EQ is the same deal as primo, it is a hit or miss. You just gotta experiment with them and see which one suits best.

 

[RockyP]

It is not a myth. Primo has a metabolite that inhibits E2 conversion. However, the pharmacokinetics of the mechanisms of actions are not 100% understood. But honestly we do not need to, it is pretty straight forward, some people get more e2 inhibition from it than others, I'm sure some get virtually none. Certainly does not act like a SERM, Mast does. EQ is the same deal as primo, it is a hit or miss. You just gotta experiment with them and see which one suits best.

Succinct summary. This is how I understand it. I aromatize like a bastard so I can run primo even a little Higher than test. Lucky me. Bad for wallet.

 

[readalot]

He's a retard and we don't like those. Money doesn't change that.

He's coming around. You don't really mean that. Let's give peace a chance. We are on the verge here.

 

[sionnach]

He's coming around. You don't really mean that. Let's give peace a chance. We are on the verge here.

 

[readalot]

For science and shit? Better?

Haha.

 

[malomkarom]

He's coming around. You don't really mean that. Let's give peace a chance. We are on the verge here.

Nah man, I do kindamean that. Gotta draw the line somewhere.

He's gonna get control bloods, receive E2 results 3 times this high and just blame it on a new vial he opened, will change injection frequency and blame it on that or find a new reference range from fucking Zimbabwei or something and claim he's still in it so his 23->75 serum E2 jump means 0 change in E2 cause it's in (a) range....

 

[readalot]

Nah man, I do kindamean that. Gotta draw the line somewhere.

He's gonna get control bloods, receive E2 results 3 times this high and just blame it on a new vial he opened, will change injection frequency and blame it on that or find a new reference range from fucking Zimbabwei or something and claim he's still in it so his 23->75 serum E2 jump means 0 change in E2 cause it's in (a) range....

Well I hope we get the control where all else kept the same except no primo. I would take the guess E2 would come back higher but his SHBG would most likely be higher as well. Hence the beauty of Free E2 assay. We dont have that here so we could compute free E2 using Maser model which is similar math to Vermeulen. Happy to help if OP gets the data.

 

[malomkarom]

Well I hope we get the control where all else kept the same. I would take the guess E2 would come back higher but his SHBG would most likely be higher as well. Hence the beauty of Free E2 assay. We dont have that here so we could compute free E2 using Maser model which is similar math to Vermeulen. Happy to help if OP gets the data.

I will of course follow the thread to learn and laugh, I can't even act like I can forget this all happened and I'm not interested in either the topic or this very case.

Gonna be interesting, I just gave up trying to achieve anything here. He's clearly not open to the idea of having to change his mind at all. With the arguments he put up, I just can't think of him as a problem that can be solved.

It's sad stuff seeing some of his markers but he isn't gonna change anything.

Edit thanks for the knowledge by the way, I've learned a lot from you, not just about gear but patience and composure aswell.

 

[cousinmuscles]

Fine. Is this supposed to stay up here for all time?

What is the number supposed to be?

Check this out @readalot
Free test almost double the upper limit, so more like triple an average result of about 90. Yet Total Test still in normal range.

Also, in regards to primobolans AI capabilities, this test result is excellent proof. As mentioned previously many times in this thread, everyones response is different so experiment carefully with ratios of test/primo.

 

[readalot]

Free test almost double the upper limit

Quest's upper limit for free Test by equilibrium dialysis is screwy. Labcorp goes up to 28 ng/dl IIRC.

Thanks.

 

[cousinmuscles]

Increased clearance rate from low SHBG will result in lower totals but 23 is still minuscule for the amount of free tests this dude has.

I don't understand how lower SHBG doesn't result in higher Free T. Claiming that it does not seems to go against all of the text that I am aware of, e.g.

https://genetic.org/wp-content/uploads/2016/01/KS-Testosterone-Hypogonadism-Guidelines-2018.pdf

https://www.endotext.org/wp-content/uploads/pdfs/laboratory-assessment-of-testicular-function-2.pdf

If you go to a Vermeulen calculator and adjust just the SHBG, lowering it increases your Free T, increasing it decreases your Free T.

Lowering SHBG won't cause highER Free T. It will keep Free T at the same however since there is no SHBG to bind to testosterone, bound testosterone (and thus total testosterone) will decrease. Then you will ask, if bound testosterone was released, why isn't Free T up? Because Free T does not last as long as bound T. Free T will do it's work and then get aromatized or self destruct. Bound T would have just floated around for much longer, resulting in higher Total T serum levels.

 

[cousinmuscles]

Hats off mr @eryximachus for being responsive and keeping a civilized tone in the last responses. If you keep doing this and do a repeat blood test, with the same test and GH dosage but no primo, you'll find how effective primo is on lowering your estrogen for you personally.

 

[readalot]

Lowering SHBG won't cause highER Free T. It will keep Free T at the same however since there is no SHBG to bind to testosterone, bound testosterone (and thus total testosterone) will decrease. Then you will ask, if bound testosterone was released, why isn't Free T up? Because Free T does not last as long as bound T. Free T will do it's work and then get aromatized or self destruct. Bound T would have just floated around for much longer, resulting in higher Total T serum levels.

Good summary. Great to have folks explaining this in a better way. I need help on the explanations so this can reach larger audiences. Hope the picture above was helpful.

The mental picture I find instructive is Test dose sets free T and then Total T snaps to whatever value based on free T and SHBG.

Hence

TT = f(FT, SHBG)

Not the way we learned which is

FT = f(TT, SHBG)

Thats the way the calculator works but not how the body works.

SHBG is f(alot of shit including androgen load and especially 17aa AAS dosing).

 

[abz94]

It is not a myth. Primo has a metabolite that inhibits E2 conversion. However, the pharmacokinetics of the mechanisms of actions are not 100% understood. But honestly we do not need to, it is pretty straight forward, some people get more e2 inhibition from it than others, I'm sure some get virtually none. Certainly does not act like a SERM, Mast does. EQ is the same deal as primo, it is a hit or miss. You just gotta experiment with them and see which one suits best.

I havent done primo yet but this is exactly what ive read online too.

 

[readalot]

Good summary. Great to have folks explaining this in a better way. I need help on the explanations so this can reach larger audiences. Hope the picture above was helpful.

The mental picture I find instructive is Test dose sets free T and then Total T snaps to whatever value based on free T and SHBG.

Hence

TT = f(FT, SHBG)

Not the way we learned which is

FT = f(TT, SHBG)

Thats the way the calculator works but not how the body works.

SHBG is f(alot of shit including androgen load and especially 17aa AAS dosing).

Then add on top not doing LCMS testing for Total
Test and Total
E2 and equilibrium dialysis for FreeT and FreeE2. Now you got utter confusion with the potential for explicit chemical inference of other compounds in the mix on the analytical testing results.

 

[malomkarom]

Ah man, I kinda miss the rush already, it's been 2 days...

 

[Texas.Redneck]

It was about 2014 that Primo became commonly available. I've probably run 15 cycles of it since that time with 200mg of testosterone. Never found it affected estrogen levels significantly.

Schering never pursued a breast cancer indication - and aromatase inhibitors weren't really available until around 1990. There was a market demand. Even Masteron itself is not particularly strong at reducing estrogen and the breast cancer doses for women was actually rather high - 400mg or so.

It's odd to me, especially as this info is available on all the chatbot services to some degree. One would think this age of AI would reduce bioscience, but it doesn't appear that is the case.

One reads other forums, and complete loons are whining about how 100mg of primo "crashes" their estrogen. Very strange to me.

I only thought that Primo had no aromotization. I didn't know it was known to be an AI till I just read this post that was posted after this post:

Q

Thread 'Test/Primo - Very Low E2 Guidance'

Jun 14, 2025

Currently take:
- 300mg Test-C
- 350mg Primo

Plus Metformin, dutasteride and minoxidil (if it matters). No AI, but my bloods just came back with my e2 at 6.8 and with the fatigue I've been feeling, I can believe it. I can certainly drop the primo, but if anyone has any ideas that are better, I sure would appreciate it.

In my research (using that search function up there), I haven't come up with too much except for some folks saying to run DBOL which seems a little bit like throwing the baby out with the bathwater, but maybe I'm wrong.`

• quarter
• Replies: 37
• Forum: Steroid Forum

 

[DonTesto]

I only thought that Primo had no aromotization. I didn't know it was known to be an AI till I just read this post that was posted after this post:

Q

Thread 'Test/Primo - Very Low E2 Guidance'

Jun 14, 2025

Currently take:
- 300mg Test-C
- 350mg Primo

Plus Metformin, dutasteride and minoxidil (if it matters). No AI, but my bloods just came back with my e2 at 6.8 and with the fatigue I've been feeling, I can believe it. I can certainly drop the primo, but if anyone has any ideas that are better, I sure would appreciate it.

In my research (using that search function up there), I haven't come up with too much except for some folks saying to run DBOL which seems a little bit like throwing the baby out with the bathwater, but maybe I'm wrong.`

• quarter
• Replies: 37
• Forum: Steroid Forum

It's an AI for some people only, most people I'd say. For some the effect is neutral at best, for others it crushes their e2 to the ground. You have to find out but 9/10 times it'll lower your e2 in some capacity