Forbindelser, der undertrykker aktive oxygenspecies eller bortskaffer radikaler såsom dimethylsulfoxid, β- caroten, ætanol, formiat og mannitol ville forventes at mindske PDT - aktivitet.
Compounds that quench active oxygen species or scavenge radicals, such as dimethyl sulphoxide, b-carotene, ethanol, formate and mannitol would be expected to decrease PDT activity.