If i take 30 ml of nyquil the day before my 5 panel drug test, could it give a false negative on the test?

False neg for what?: Most people are not usually concerned about false negative results. The exception being the people who are prescribed a medication and rather than taking it, are selling it on the street. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.