MastaPlex 100 from XtLabs is an oil-based injectable that packs 100 mg of drostanolone propionate (Masteron) into each milliliter, all in a 10 ml multi-dose vial.

You’re getting drostanolone propionate (C23H36O3), which comes from DHT. It’s not the most anabolic thing out there, but it really shines with its strong anti-estrogenic effect. The short propionate ester means it sticks around for just 2-3 days per shot. You don’t have to worry much about water retention or liver stress. It’s sterile and meant for intramuscular injections—usually glutes or delts.

MastaPlex is a classic for cutting phases or right before a contest. It hardens muscles and brings out veins and density, especially if you’re already pretty lean (think under 10% body fat). It helps you keep strength and burn fat by activating androgen receptors. Its anti-estrogen punch also helps keep gyno away, especially if you’re stacking with things like DianaPlex or DecaPlex.

How to Use
Men usually run 300-600 mg per week (so 3-6 ml), breaking it up every other day or three times a week to keep levels steady. Cycles last 6-12 weeks. Women stick to 50-100 mg weekly. Always stack it with a testosterone base. Don’t skip your post-cycle therapy—grab Clomid, Nolva, or HCG. It really works best if you’re already lean.

Why People Like It
Expect rock-hard, dry muscle gains—no puffiness or bloat. You’ll see better fat loss and strength, and you probably won’t need an aromatase inhibitor like Arimidex since Masteron works as its own AI. It’s a favorite for finishing a contest prep, and side effects are usually mild for a DHT-based steroid.

If you’re carrying more body fat, don’t expect much—this stuff needs you to be lean first. It will suppress your natural testosterone, so PCT is a must. Some people get more androgenic sides, especially if they’re prone. Quality can vary since it’s an underground lab product, and the short ester means you’ll be pinning pretty often.

Side Effects
Watch out for androgenic stuff: acne, hair loss (especially if you’re balding already), aggression, and possible prostate issues. It can mess with cholesterol too—usually dropping your HDL. Some people get insomnia or changes in libido. Women rarely get virilization, but it’s not impossible. Keep an eye on your lipids and blood pressure. It doesn’t aromatize, but running HCG is still smart.