Casein (Optimum Nutrition) (1 Serving)

Test a smaller serving of plain, unsweetened casein powder (for example, half your usual dose) and compare your glucose response over several separate days.

Choose an unflavored casein product with no added sugar, maltodextrin, syrup, or high-carbohydrate fillers; compare labels because formulations can differ substantially.

Take casein as part of a mixed meal rather than alone, pairing it with non-starchy vegetables such as spinach, broccoli, cucumber, or zucchini and a source of fat such as avocado, olive oil, or nuts.

Mix casein with water or an unsweetened milk alternative rather than juice, sweetened milk, or flavored beverages.

Avoid combining casein with rapidly absorbed carbohydrate foods, especially around the same time; if you need a snack, consider berries, plain Greek yogurt, or nuts in portions that fit your glucose goals.

Review the timing and repeatability of the response using the same serving, meal context, activity level, and sleep conditions; discuss persistent or unexpectedly large rises with a registered dietitian or clinician.