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Protein Products

Gold Standard
100% Casein







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Faster digesting protein is desirable immediately before and after exercise to help refuel recovering muscles, but slow digestion and absorption may be more beneficial at other times including bedtime when your body typically goes for hours without food. Casein products are acid sensitive and thicken in the stomach. Compared to some other proteins, it can take longer for our Gold Standard 100% Casein™ to be broken down into its amino acid subcomponents. By using only premium micellar casein as a protein source, we've created a formula that sets the standard for slow digesting protein support. 24g of Micellar Casein

  • 24g of Anti-Catabolic Micellar Casein
  • Nearly 5 Grams of Naturally Occurring BCAAs per Scoop
  • Nearly 5 Grams of Naturally Occurring Glutamine and Glutamic Acid per Scoop

Athletes Who Use Gold Standard 100% Casein

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Rachel Ponder

“This is a staple for me when dieting. I have it at night because the slow digesting benefits keep me from being famished the next morning and it's like a nightly treat!! I don't drink it though; I mix it with a little bit of water and nut butter to make a nice pudding batter and stick in the fridge for 10-20 min. If I'm wanting a warm treat, I'll mix it with a little egg whites and microwave for 1 min and top it with some nut butter!”

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Tobias Young

“I like to cook and bake with casein because of the thicker texture, but I also love my protein pudding. Casein is a night time staple for me because I want the slow release of aminos in my blood stream as I sleep. Casein also helps keep me satisfied, so I don't wake up hungry in the middle of the night.”

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Michael Del Zoppo

“Gold Standard 100% Casein is a great source of night time recovery. I mix up casein an hour before bed to help rebuild and recover and to keep me full throughout the night. Casein protein can help provide longer lasting amino acid support compared to whey”

Optimum Nutrition Quality

At ON we are proud to know that we are one of the few sports nutrition companies who own and operate their own production facilities. While it's true that ON is one of the world's largest producers of sports nutrition products, we remain focused on being recognized as the best. In fact, our requirements for raw materials are so strenuous that it's not unusual for ON Quality Assurance Technicians to reject entire truckloads of raw materials that do not meet our high standards. We like to think that we take as much pride & care in crafting our award-winning supplements as our consumers do with crafting their physiques and fitness accomplishments.

There is Only One Gold Standard

Optimum Nutrition's Award Winning supplements have consistently delivered the Highest Quality products to athletes across the globe -- Here is a brief look at how.