How to Prepare for a Lie Detector (Polygraph) Test

Here are the guidelines to follow to help ensure your polygraph exam will have the best chance of producing correct results.  In some cases, polygraph exams can produce inaccurate results because the person taking the exam (the “Examinee”) did not properly prepare for the exam, or were not informed by their Examiner of the guidelines that should be followed.  

  1. Get plenty of rest before the exam.  The Examinee should be alert during the exam, and be able to understand everything the Examiner is trying to explain or discuss.  Failure to understand  (or to follow) instructions due to fatigue can cause issues.
  2. Eat a normal meal before the exam.  Even if eating food is not a usual practice in the hours prior to an exam, it is advisable to eat at least a small amount of food.  Low blood sugar can effect the quality of the data collected during the procedure.
  3. Be well hydrated before the exam.  Drink plenty of fluids, but not so much that you need a bathroom break every few minutes.
  4. Avoid illegal and mind-altering drugs (including marijuana and methadone) and alcohol for at least 18 hours prior to the exam.
  5. Take daily prescription medications as prescribed.  If this is a new drug for the Examinee, the exam should not be administered until the body has become accustomed to the drug’s effects.  This can take a few weeks to months depending on the drug.  Do not stop taking a long-term medication in the days before the exam because that “sudden stoppage” can have unpredictable effects on the Examinee’s physiology.
  6. As-needed medications may be taken as long as they do not have any sedating effects.  Mild pain meds, and most cold/cough and allergy medicines, are acceptable.  Vitamins are not a problem.
  7. If the Examinee is in any pain, the exam should be postponed.  The human body’s pain response will override any other reactions that may appear in the charts.
  8. While attached to the polygraph, the Examinee should avoid taking deep breaths as much as possible, and should also avoid holding his/her breath.  These two actions can cause a rapid change in oxygen levels, which can affect body chemistry in unpredictable ways.
  9. The Examinee should be fluent in the language to be used by the Examiner.  Otherwise, an impartial interpreter should be used.  Failure to understand the nuance of a question will affect the test results.  The interpreter can not be personally acquainted with the Examinee, and can have no interest in the outcome of the exam.
  10. Clothing should be comfortable, but not loose-fitting.  Bulky clothing, like sweatshirts and jackets, will need to be removed.  Access will be needed to the torso, left arm (usually) for the blood pressure cuff, and both hands.
  11. The Examinee should be able to sit perfectly still for up to seven minutes at a time.
  12. All foreign substances should be removed from the Examinee’s hands and arms before the exam.  This includes lotions, moisturizers, anti-bacterial gels, and tanning oils.  Soap is ok to use.
  13. The Examinee should not discuss the test issues with anyone other than the Examiner on exam day, prior to the exam.
  14. Avoid arguments or intensely emotion events on the day before, and the day of, the exam.  There is good reason that the APA Standards of Practice prohibit testing of anyone following an interrogation.
  15. Caffeinated drinks may be consumed in moderation, or in amounts the Examinee is normally used to drinking.  Do not drink more caffeine than you would normally drink, before the exam.
  16. The Examinee should never be surprised by the exam.  Provide sufficient notice, at least a few days ahead of time.
  17. If the Examinee has a serious medical condition, or is pregnant, this must be disclosed to the Examiner ahead of time.  Many examiners will not test a pregnant woman, while others have established certain conditions on these exams.  If the Examiner is willing to provide the exam, a medical release form may be required from the treating physician.
  18. If the Examinee has a disability, this should be transmitted to the Examiner ahead of time so that suitable preparations can be made to accommodate the disability.

Michael Martin, GPN Owner

GLOBAL POLYGRAPH NETWORK®

Established in 1987, Global Polygraph Network® is the world’s largest and most trusted polygraph (lie detector) company with services available at hundreds of locations by highly-trained experts worldwide. Avoid “discount” polygraph frauds and “over the phone” testing scams. We only provide real polygraphs by real examiners. Trust our A+ BBB rating, up-front pricing, and written guarantee.