Amazon.com: Ronnie Coleman Signature Series L Carnitine XS 3000 Liquid, Amino Acids Metabolism and Lean Muscle Strength Support, Stimulant Free, Sugar Free, Zero Carbs, Orange Smash, 16 Oz : Health & Household The supplements aisle at Costco is loaded with lots of prodcuts, here's what I think of a few of them. BobbyParrish Facebook Siren Labs L Carnitine Elite Burn Fat Loss and Metabolism Activator Lemon Lime Forzagen Premium L Carnitina 60 Cpsulas Costco Mxico Zena Monohydrate Creatine + D3 K2 gummies are now at Costco. @zena_nutrition As a private label supplement manufacturer myself, I can tell you that creatine monohydrate is well studied and has great benefits. D3