What OTC medicine dilate your pupils?

Over-the-counter (OTC) medications that can cause pupil dilation include certain antihistamines, such as diphenhydramine (Benadryl). These medications can have anticholinergic effects, leading to pupil dilation as a side effect. Additionally, some decongestants may also contribute to this effect. However, pupil dilation is primarily associated with prescription medications and recreational drugs rather than OTC options.