How long are you prepping for?
How high are you running the test? What dosages have you already planned out?
I have done alot of reading on these compounds and if it was me I'd run (and these dosages are what I would run) not telling you to run these as I don't know how you aromatise etc
750 test
600 primo
300 mast
Then 6-8 weeks out Drop the primo to 300 and bump the mast up

I'd get a coach. Or ask specifically for guys opinions that have actually prepped for a contest.

If Im remembering you right, you're more advanced than about 90% of the ppl in here, the rest of us will likely never ever step foot on a stage, and have no idea about contest prep. Not trying to talk shit about most of us. Just saying...

@Pandateston might be able to help.

bro don't listen to negative nancys in this chat.

Both are amazing DHT compounds, I love running both because 1 (mast) eliminates all E2 mental/physical side effects while the 2nd (primo) actually lowers e2 on paper. When I run these together, I feel like a GOD. I would say run mast higher than primo for sure and keep an eye on E2.

600 TEST 600 MAST 480 PRIMO <3

Currently running 350 test, 250 primo, 200 mast prop (had a bunch of it left from The Great Masteron Shortage of 2025), and some anavar preworkout. Lotta DHT derivatives! Hairline intact - baldness doesn't run in the family - and joints feel fine. Bloodwork next week to see where things are, including sensitive estradiol. I'm guessing upper teens, maybe low 20s, but we'll see.

Pros: nice cuts, thin skin from less subcutaneous water, libido.
Cons: My guess is my HDL is going to be pretty crushed despite 6g fish oil (2g+ DHA), citrus bergamot, red rice etc. Primo is not as hard on my lipid profile, while tren and mast are the hardest on my HDL. LDL and ApoB are kept in range with the ancillaries and Reta, but that HDL can get pretty low.

Run the oral primo week before and into show. Some combine oral winny primo. You'll have sore joints but you're not hitting heavy anyways. I believe makwa made several posts on his prep. Oils get pulled...hgh pulled 2 weeks out ....orals in. See if @Greg can get you into the advanced group if its still there.

Might be too drying/harsh on the joints. Also potential to fuck your hairline up if you're prone to it. You got to find a good balance through trial and error. Use masteron prop for that, if you got the balance wrong it's easier to make adjustments.

My approach is to start with a primo dose that works for you as baseline. Than add in masteron prop and gradually increase the mast dosage till you get the results/look you want, with as little side effects as possible.

Definitly synergistic if you get the balance that works for you right. I loved it tbh.

Th only con that I can think of is that you have a another vial to draw from if you don’t have the elusive blend. It makes sense if you’re running test high enough that the masking effect that Masteron has in many isn’t adequate for your purposes. I prefer Masteron to add mgs to a cycle but I would throw in a small amount of primo if my E2 number is higher than I’m comfortable with. If primo doesn’t crush lower your estrogen too much and you can just run it higher and leave out the Mast. If you are comfortable with higher estrogen but don’t get any sides then Masteron without the primo will do the job for most.

Not for show prep, but I know a shit ton of dudes running it, but most are running Test, Mast, Primo, the TMP Blend and they swear by it, they buy the shit by the gallon. But if you’re just curious about Primo, mast, both are solid choices and well worth running.
Pros: Primo is considered one of the least harsh compound there is, not massive gains but solid gains and most are not lost when cycling off.
Cons: Can be pricey, only con there is
Mast Pros: it will help dry you out, makes vascular as fuck and it’s affordable.
Cons: about the same, not many but one would be it’s a DHT Derivative and some worry about hair loss, I haven’t noticed that and been running it for a hot minute.