Black coffee (1 1 Cup) and Creatine Monohydrate, pure (1 Serving)

Test coffee and creatine separately on different, otherwise similar days; pure creatine monohydrate is not usually expected to raise glucose, while caffeine can cause a temporary rise in some people.

Reduce the coffee dose, choose decaf or half-caf, and avoid taking it immediately after waking if that is when your readings rise most.

Have coffee after a balanced meal rather than on an empty stomach; options include eggs with non-starchy vegetables or plain Greek yogurt with nuts/seeds.

Use only unflavored, single-ingredient creatine monohydrate and verify that the product contains no sweeteners, carbohydrate fillers, flavored powders, or pre-workout ingredients.

Keep the creatine dose consistent, such as 3–5 g daily, mixed with water, and avoid combining it with sugary drinks or supplements.

Confirm the pattern with repeat measurements under the same conditions and discuss persistent or large rises with a clinician, especially if you have diabetes or take glucose-lowering medication.