A Crown Stupifier is a substance ingested into the body and that suppresses or otherwise diminishes the functioning of the Crown Chakra.
Crown stupifiers include substances like alcohol, pharmaceuticals (psychoactive or otherwise), neurotoxins, and any other chemicals which interfere with the physiological, cellular, neural, or quantum operations of the brain. This includes, it should be noted, the slew of chemicals that you find in processed foods.
Contrast crown stupifiers with Connection Supplements.
Speaking of the need to "put the brakes" on Nadir Experience, particularly one where Flooding is occurring, Timothy Leary points to "Thorazine, alcohol and narcotics" as substances which "help apply the brakes."
Alcohol, narcotics, opiates, psychoactive antidepressents (Prozac), Flouride (a neurotoxin), processed food additives, and perhaps even frequencies of electromagnetic radiation could be investigated as possible crown stupifiers.
It is also important to note that brain operations can be very subtle and even current technologies like the MRI (Magnetic Resonance Imaging) are insufficiently sensitive to document the range of physical and quantum operations carried out in the brain. Therefore, just because an effect is not observed in the short term does not mean an effect (which may be cumulative and damaging over the long term) is not present.
Crown stupefiers are not confined to substances. The school system, which its overemphasis on the development of left brain modules and skills, television, and other forms of media that discourage critical thinking and interfere with the development of balanced brain functions, can also be considered crown stupifiers. In addition, a pathological socialization process, abusive parenting, and negative emotional experiences can contribute to crown stupefaction through the suppression of crown chakra energies.
Harold Johson provides a fascinating and highly recommended look at the destructive power of alcohol