High-Dose Test: Overnight (8-mg) Test


Send Email

Recipient(s) will receive an email with a link to 'High-Dose Test: Overnight (8-mg) Test' and will have access to the topic for 7 days.

Subject: High-Dose Test: Overnight (8-mg) Test

(Optional message may have a maximum of 1000 characters.)



  • Dexamethasone (8 mg) is taken orally between 11 pm and midnight, and a single blood sample is drawn at 8 am the next day for measurement of serum cortisol.

  • With this protocol, the 8 am serum cortisol concentration is <5 μg/dL in most patients with Cushing disease (i.e., a pituitary tumor) and is usually undetectable in normals.