Description : How fast do you build up a tolerance to DPH (benadryl)
Last Answer : I'm not a doctor and can only speak from my own experience. I have allergies and occasionally take Benadryl in the evening to reduce symptoms I only take 25 mg (1 pill ). If I wake up in the ... DPH. I figure anything that has that effect on my body cannot be healthy to take for a sustained period.