How to prepare for Cortisol Test

Preparation for a cortisol test depends on the test type (saliva, blood, urine). For saliva tests—common in home kits—collect the sample in the morning between 6:00 and 8:00 AM, before eating, drinking, or brushing teeth. Avoid caffeine, alcohol, and nicotine for 12 hours prior. Also avoid intense exercise and acute stress, as they transiently raise cortisol. For blood tests, fasting is often required. A single measurement is of limited value because cortisol follows a strong circadian rhythm. MyBody-X does not appear to offer a dedicated cortisol test; if you are using a third-party kit, follow its instructions carefully. Evidence for home cortisol testing is moderate: it can provide orienting data but cannot replace clinical diagnosis for conditions like adrenal insufficiency or Cushing's syndrome. Caveat: self-testing without medical oversight may lead to misinterpretation.