Mouth swab drug tests can check for the presence of the following substances in a person’s system: Alcohol Amphetamines Barbiturates Benzodiazepines Tetrahydrocannabinol (THC) — a compound in cannabis Cocaine Methamphetamine Opioids Phencyclidine (PCP) As consumables manufacturer in the field of in vitro diagnostic, MEDICO offers a range of mouth flocked swabs, If you are interested, please contact us.