Good preparation for a polygraph examination increases the effectiveness of 87% down 95-98%. Poor preparation—on the contrary—can result in an inconclusive or false result. In this guide, we go through everything worth doing in week, day i hours before the session. The material is based on practice 369-Agent and protocols approved by the American Polygraph Association (APA).
A week before the test
1. Consult your medications with an expert
If you regularly take medication—especially sedatives, sleeping pills, antidepressants, hypertension medications, or heart medications—be sure to inform the specialist before scheduling your appointment. In most cases, the test can be performed without any medication modifications, but the specialist must be aware of your medication to consider its impact on the interpretation of the charts. Don't stop taking your medications on your own — this is often more dangerous than postponing the test. Full list of contraindications: contraindications to polygraph examination.
2. Plan your day accordingly
Choose a day when you have no other burdensImportant meetings, deadlines, and family issues that need to be resolved immediately after the session. A session lasts 90-180 minutes, plus travel time. After the examination, it's a good idea to have a few hours to calmly unwind from the "intense concentration" mode.
3. Learn how a polygraph works
Knowing the mechanics significantly reduces stress during a session—and a low "baseline" stress level helps produce a cleaner result. Read how does a polygraph work — this is a 10-minute read that will make the whole process easier.
The day before the test
1. No alcohol - minimum 24 hours
Alcohol in the body disrupts the autonomic nervous system. Even 0.2 per mille is disqualifying. A good rule of thumb: drink no more than 24 hours before your scheduled session. After larger amounts, drink no more than 48 hours.
2. No intense training
Strenuous training (marathon, intense strength training, competitive sports) the same day or the night before exhausts the body and disrupts physiological responses. A light walk is fine. A run in the forest with a heart rate of 80% max should be postponed for another day.
3. Light dinner
Your evening meal should be light and digestible. Avoid heavy foods, spicy foods, and large amounts of fat—anything that could cause stomach upset in the morning.
4. Early sleep - minimum 6-8 hours
Exhaustion after a night without sleep significantly increases the chances of an inconclusive result. Go to bed early and get at least 6 hours of sleep—ideally 7-8. If you have trouble sleeping, don't try to solve them with sedatives—this will disqualify you from the test. A better solution: a quiet evening without screens, a warm shower, and peppermint tea.
Day of the examination - morning
1. Normal, light breakfast
Don't go hungry—hunger causes hypoglycemia, which can impair physiological responses. But don't overeat—a heavy meal right before the session isn't the best idea. Ideally, a light breakfast 2-3 hours before the test. Oatmeal with fruit, a white meat sandwich, eggs—whatever you consider a normal breakfast.
2. Last coffee - at least 4 hours before the session
Caffeine increases your heart rate and blood pressure. If you drink coffee 30 minutes before the test, your baseline will be artificially elevated—and the interpretation of the results may be incorrect. A good rule of thumb: your last coffee should be at least 4 hours before your scheduled session. The same applies to strong tea, cola, and energy drinks (the latter at least 8 hours before).
3. No smoking one hour before the session
Nicotine raises your heart rate. If you smoke, avoid smoking for the last hour before the test. Addicts should try to do this, although the expert understands that completely giving up half a day is difficult for smokers. A realistic rule of thumb: have your last cigarette 30-60 minutes before the test.
4. Casual clothes
Comfortable, not too tight. The expert will apply a cuff to your arm (like a blood pressure cuff), two breathing tapes (chest and abdomen), and two finger electrodes. A long-sleeved blouse that can be rolled up is OK. A cocktail dress with bare shoulders is impractical. Practical: a T-shirt, a shirt with unbuttoned cuffs, casual attire.
Immediately before the session
1. Arrive 15 minutes early
Give yourself time to park, get to the office, and sit quietly for 5-10 minutes to allow your heart rate to return to normal upon arrival. Rushing adds unnecessary stress.
2. Tell the expert everything
Any information that could affect the measurement—medications, illnesses, lack of sleep due to a sick child, a recent family conflict, your last coffee an hour before despite recommendations—all of this must be known to the expert. Don't be shy about sharing it. It's better to postpone the date than to pretend that everything is OK, if it isn't. A professional expert doesn't treat a postponement as a problem—he treats it as a professional decision by both parties.
3. Discuss the questions
Expert mandatory will discuss with you every relevant question asked during the session. There are no surprise questions. This is the moment where you can ask about the wording, request clarification of the timeframe, or request that the words be changed to ones you understand better. The better you understand the question, the more credible your answer will be.
During the examination
1. Sit still
A motion sensor in the seat records all muscle tension, finger pressure on the floor, and leg movement. Attempts at counter-methods are detected and interpreted as cheating. The best strategy: just sit still and answer.
2. Answer "yes" or "no"„
The polygraph responds to simple, one-word answers. Explanations, descriptions, "because it was so..."—no. Question: "Between January 1st of this year and today, did you have sexual contact with anyone other than your partner?" Answer: "no." Or: "yes." You can add explanations after the session, in conversation with the expert.
3. Breathe normally
Some people try to "consciously control their breathing," thinking this will protect them. The effect is the opposite: the unnatural breathing pattern is immediately visible on the chart and interpreted as an attempt at a counter-method. The best strategy: breathe as usual, don't think about breathing.
After the examination
1. Short closing interview
The expert checks how you're feeling, whether everything was clear, and if there are any comments from you. This is also the time to ask about the next steps.
2. Waiting for feedback
Chart analysis takes 2-6 hours of expert work. You will receive a written opinion within 48 hours via email with an encrypted attachment or in person. Don't ask about the results right after the session—the expert won't tell you "on the spot," because initial impressions often differ from the final analysis.
3. What next with the result
What happens next is up to you. The result isn't a verdict. It's data you can base your decision on: a conversation with your partner, couples therapy, legal proceedings, or internal company proceedings. If you plan to use the opinion in court, read this. Is a polygraph evidence in court?.
The most common preparation mistakes
- Taking a sedative "for the nerves" invalidates the test.
- Last minute coffee artificially raises the baseline.
- A sleepless night + trying to catch up on sleep after the session - exhaustion interferes with the measurement.
- An attempt to "prepare counter-methods" watched on YouTube - experts detect them, more in the article Is it possible to lie to a polygraph?.
- Failure to tell the expert about the medications you are taking will result in an incorrect interpretation.
- Going for a checkup immediately after a conflict with your partner - your "baseline" is artificially raised.
Summary - checklist 24 hours before the session
- ✅ No alcohol for at least 24 hours
- ✅ No sedatives
- ✅ At least 6-8 hours of sleep
- ✅ Light breakfast 2-3 hours before the session
- ✅ No coffee 4 hours before
- ✅ No cigarettes one hour before
- ✅ Comfortable clothes
- ✅ 15 minutes earlier at the venue
- ✅ Open conversation with an expert about medications, illnesses, and well-being
- ✅ Calm "yes/no" answers without explanation during measurement
Meeting these conditions ensures effectiveness 95-98% and reliable opinion within 48 hours. Price-list. Covering all provincial capitals. First contact: telephone or WhatsApp.
See also: Contraindications · How does a polygraph work? · Sample questions · Will a polygraph detect infidelity?