Products Bio

Muscletech, Amino 4XL, SX-7, Black Onyx, Fruit Punch Explosion, 9.35 oz (265 g)


Research & Development
Next Generation 5:1:1 Muscle Building BCAA Formula
Test Subjects Increased Strength by 40%¹
Builds Muscle, Enhances Performance & Boosts Endurance²,³
Powerful Dose of Leucine Including PepForm & ActiveTR Leucine
Natural & Artificial Flavor
Delicious Taste!
Dietary Supplement
50 Servings
Next Generation 5:1:1 Musclebuilding BCAA Formula

The new, supercharged musclebuilding amino formula from MuscleTech SX-7 is here. Introducing, Amino 4XL SX-7 Black Onyx, the only BCAA product that delivers a powerful 5:1:1 BCAA ratio (which includes both PepForm leucine and ActiveTR leucine) combined with the clinically studied musclebuilding power of Peak ATP. Amino 4XL SX-7 Black Onyx also contains several other popular ingredients, such as taurine, L-citrulline, glutamine and an electrolyte blend that features coconut water. With Amino 4XL SX-7 Black Onyx, you get everything you want in a BCAA formula and more!

L-leucine (as L-leucine, PepForm leucine & Active TR leucine) - L-leucine is the BCAA with the highest anabolic potential. It activates the mTOR enzyme, which amplifies protein synthesis. The three different forms of leucine provided by Amino 4XL SX-7 Black Onyx ensures that your body gets a steady supply to keep your body in a prime anabolic state. ¹In fact, a 4 g dose of leucine delivered in 1 scoop of Amino 4XL SX-7 Black Onyx is shown in a clinical study to help subjects increase their 5-step max strength by over 40%.
²Peak ATP (Adenosine 5'-triphosphate disodium) - Hard training subjects who supplemented with 400 mg of Peak ATP in a 12-week study at a leading university increased strength more than the placebo group. Even better, these same subjects gained 8.8 lbs. of lean muscle versus the placebo group, which only gained 4.6 lbs. -that's 90% more lean muscle.
BCAAs - Amino 4XL SX-7 Black Onyx delivers a potent BCAA ratio of 5:1:1 to ensure you get a clinically validated 4 g dose of L-leucine in each scoop.
³Taurine - The 1 g dose of taurine found in each scoop of Amino 4XL SX-7 Black Onyx has been shown to increase endurance performance.
L-citrulline - A precursor to L-arginine that provides a spike to plasma arginine levels.
Electrolyte blend - Amino 4XL SX-7 Black Onyx delivers coconut water along with an electrolyte blend that helps restore electrolyte levels that are depleted during exercise.
Glutamine - The most abundant conditionally essential free amino acid in your body. It helps support increased cell volume, glycogen replenishment and protein synthesis.