Mast E vs Mast P

[Jp523]

With Mast E restocking very soon, what’s the play? Do y’all prefer E over P? If so, what’s the reasoning?

 

[Meetketchup]

Half-life and active compound per dose.

Unless needed to take out for a show or whatever, E is usually the play.

 

[Jp523]

It’ll be my first time running mast. Still go with e? I’ve ran primo e with no issues

 

[Meetketchup]

It’ll be my first time running mast. Still go with e? I’ve ran primo e with no issues

Mast E is more stable, so yes.

 

[Cypher]

Plug Mast into SteroidPlotter separately using daily injections for both prop and enanthate, the graphs do come out looking different.

Even with everyday pinning, prop still shows more of a dip-and-peak curve, while enanthate looks smoother and more stable, more of a steady release overall.

I’ll probably switch to Mast E once I finish the prop I have left. I also like that Mast E typically comes dosed at 200 mg per mL, it’s just more convenient volume-wise.

Mast-P is still good to go.

 

[SharpTack]

I was wondering about this as well so I’m going to try both. Sometimes the short esters just “feel” different to me. Anyone else, or is it just in my head?

 

[Cypher]

You’re not crazy, short esters really can feel different for some people.

The hormone is the same, but propionate releases faster, which means blood levels rise quicker. Your body and nervous system tend to react more to rapid changes than slow ones, so that sharper spike can feel like more energy, mood shift, or drive. Enanthate releases more gradually, so levels climb slower and feel smoother and steadier.

There are also a lot of individual variables at play. Everyone metabolizes hormones a little differently. The enzymes that cleave the ester control how fast it becomes active, while liver enzymes (like CYP3A4) handle breakdown and clearance later. On top of that, enzymes like aromatase (which converts some testosterone to estrogen) and 5‑alpha reductase (which converts some to DHT) vary from person to person and can change how strong or noticeable the effects feel, especially with faster spikes.

So yes... everyone’s different, and there are a lot of moving parts. It’s not just in your head.

For example, NPP really seems to hit me hard, but Deca doesn’t feel the same at all. Yet when I compare Mast‑P to Mast‑E, I honestly don’t notice much difference between the two. So what gives?

 

[Cypher]

Also curious how much, if any, carrier oil plays into this. In theory the oil affects depot dispersion and absorption slightly, like something thinner (Miglyol/MCT) vs thicker (CSO or sesame). I know ester length is the main driver of release speed, but could oil choice fine‑tune peaks or stabilization at all? Or is that splitting hairs compared to injection frequency and total dose?

Trying to figure out where the real variability is coming from, ester length, compound type, metabolism, or just individual nervous system sensitivity.

For what it’s worth, and I’ve said this plenty of times, I’m personally a huge fan of Miglyol over all other carrier oils. Mainly just because of how clean and smooth it is compared to the thicker, more old‑school oils.

 

[Meetketchup]

I was wondering about this as well so I’m going to try both. Sometimes the short esters just “feel” different to me. Anyone else, or is it just in my head?

Are you using the same amount of the compound in both? If so, you are getting a decent amount more of the active compound in short esters.

Also, you get more spike (Peaks and Troughs) in short esters unless injecting ED or 2x/Day.

Lastly, obviously reaches full concentration in the blood faster.

 

[SharpTack]

Are you using the same amount of the compound in both? If so, you are getting a decent amount more of the active compound in short esters.

Yes, using the same amount whether pinning test prop or cyp/enan. I havent run tren yet but I plotted an 8wk cycle of 70 ace vs 70mg enanthate/wk. Ace ED and enan every 3.5d. It seems to indicate serum levels end up higher with a longer ester. What does “getting a decent amount more of the active compound” mean vs projected serum levels?

 

[Meetketchup]

Yes, using the same amount whether pinning test prop or cyp/enan. I havent run tren yet but I plotted an 8wk cycle of 70 ace vs 70mg enanthate/wk. Ace ED and enan every 3.5d. It seems to indicate serum levels end up higher with a longer ester. What does “getting a decent amount more of the active compound” mean vs projected serum levels?

Mast E - Contains roughly 73% Drostanolone and 27% Enan
Mast P - Contains roughly 85% Drostanolone and 15% Prop

It's Prop not Ace.

 

[Bolan]

Fast acting AAS like the Prop ester are actually stronger( more potent) than the longer esters.
Wanna look like a Greek god..... TPP/NPP/Mast P

 

[Glycomann]

You’re not crazy, short esters really can feel different for some people.

The hormone is the same, but propionate releases faster, which means blood levels rise quicker. Your body and nervous system tend to react more to rapid changes than slow ones, so that sharper spike can feel like more energy, mood shift, or drive. Enanthate releases more gradually, so levels climb slower and feel smoother and steadier.

There are also a lot of individual variables at play. Everyone metabolizes hormones a little differently. The enzymes that cleave the ester control how fast it becomes active, while liver enzymes (like CYP3A4) handle breakdown and clearance later. On top of that, enzymes like aromatase (which converts some testosterone to estrogen) and 5‑alpha reductase (which converts some to DHT) vary from person to person and can change how strong or noticeable the effects feel, especially with faster spikes.

So yes... everyone’s different, and there are a lot of moving parts. It’s not just in your head.

For example, NPP really seems to hit me hard, but Deca doesn’t feel the same at all. Yet when I compare Mast‑P to Mast‑E, I honestly don’t notice much difference between the two. So what gives?

but you left out glucuranosyltransferases, hydroxylation enzymes, sulfation enzymes, all the metabolism readying the compounds for disposal via kidneys and through the bile....

 

[Cypher]

but you left out glucuranosyltransferases, hydroxylation enzymes, sulfation enzymes, all the metabolism readying the compounds for disposal via kidneys and through the bile....

Mea Culpa.

Just to clear things up and add to what I said before:

After you inject a testosterone ester, it doesn’t go straight to the liver. It first has to leave the muscle. Because it’s oil-based, it slowly absorbs into the body through small blood vessels and the lymphatic system. That absorption speed is a big reason why propionate feels faster and enanthate feels smoother... the shorter ester leaves the injection site quicker.

Once it’s in the bloodstream, the ester gets cleaved off and you’re left with active testosterone. That testosterone can bind to androgen receptors or convert into estrogen (via aromatase) or DHT (via 5-alpha reductase).

Only after that does liver metabolism really come into play. First, liver enzymes (CYP enzymes) start breaking it down. Then the body adds little chemical “tags” to it (mostly through a process called glucuronidation, sometimes sulfation). Those tags make it water-soluble so it can be removed in urine, and some through bile.

So in simple order:

Injection - slow absorption (blood + lymphatic system) - Ester removed - active testosterone - Liver breakdown (CYP enzymes) - Tagging for removal (glucuronidation/sulfation) - Excretion.

The lymphatic system affects how fast it gets in. The liver enzymes affect how fast it gets broken down and cleared.

Two different stages, different roles.

 

[netix]

Fast acting AAS like the Prop ester are actually stronger( more potent) than the longer esters.
Wanna look like a Greek god..... TPP/NPP/Mast P

What I’m running at the moment
Plus the addition of your favorite, yk11.

 

[Markenarten]

Plug Mast into SteroidPlotter separately using daily injections for both prop and enanthate, the graphs do come out looking different.

Even with everyday pinning, prop still shows more of a dip-and-peak curve, while enanthate looks smoother and more stable, more of a steady release overall.

I’ll probably switch to Mast E once I finish the prop I have left. I also like that Mast E typically comes dosed at 200 mg per mL, it’s just more convenient volume-wise.

Mast-P is still good to go.

I did that and the days changed, Mast e isn't smoother than mast p

 

[Cypher]

I did that and the days changed, Mast e isn't smoother than mast p

I’m talking about ester kinetics, not pinning frequency. Enanthate has a longer half‑life and releases slower, so the concentration curve is inherently smoother than prop, even when both are pinned daily.

 

[Markenarten]

I’m talking about ester kinetics, not pinning frequency. Enanthate has a longer half‑life and releases slower, so the concentration curve is inherently smoother than prop, even when both are pinned daily.

No you weren't, you said 'Plug Mast into SteroidPlotter' you can't get ester kinetics off steroid plotter...

 

[Meetketchup]

Injecting ED...Longer esters are more consistent in blood concentration when pinned daily than that of shorter esters. If that's what you mean by "smooth."

 

[Cypher]

No you weren't, you said 'Plug Mast into SteroidPlotter' you can't get ester kinetics off steroid plotter...

Fair enough. For clarity, ester kinetics in chemistry refers to the rates at which esters are formed (esterification) or broken down (hydrolysis). Technically, no... you can’t see ester kinetics themselves (rate law, reaction order, hydrolysis mechanism) on SteroidPlotter.

What SteroidPlotter does show are the effects of ester kinetics... how different esters influence release rate, effective half‑life, and blood‑level curves over time.

When you plug prop and enanthate separately, keep injection frequency constant, and don’t change days mid‑plot, the longer ester (enanthate) produces a flatter concentration curve, while shorter esters (prop) show more peaks and dips. That’s the downstream effect of ester kinetics, not a measurement of the chemistry itself.

At this point, we’re just beating a dead horse. The point was about controlled comparisons and ester effects on concentration curves, not whether SteroidPlotter replaces labs or models chemical reactions.

 

[62Young]

Good stuff, gentlemen. Thank you! I have a bit of P left, but I’m thinking I might want to give your E a go soon.

 

[Cypher]

Good stuff, gentlemen. Thank you! I have a bit of P left, but I’m thinking I might want to give your E a go soon.

I might’ve gone a little overboard on that take.

Truth is, both compounds are legitimately solid, and when used correctly, they can be incredibly effective... especially our shit.

 

[62Young]

I might’ve gone a little overboard on that take.

Truth is, both compounds are legitimately solid, and when used correctly, they can be incredibly effective... especially our shit.

The P is working well for me right now. Pinning 4x/week. Still, the ester kinetics of the E is attractive. And why not.

 

[Cypher]

I really shines in the central nervous system benefits for me, now I understand why so many guys like to stack it with tren.

It's one of my favorite compounds for sure.

 

[Knarfster]

I might’ve gone a little overboard on that take.

Truth is, both compounds are legitimately solid, and when used correctly, they can be incredibly effective... especially our shit.

Unfortunately last cycle, I thought I was doing 500mg/week of Primo and 300mg/week Mast E. Well the Primo was fake so I was doing 800mg/week Mast E!

I have since obtained 2 brands of real primo (sent both off to Jano) and still have Mast E (also sent to Jano) so I will give it another try next month.