The misuse of opioids, including codeine which is sold over-the-counter (OTC) in United Kingdom (UK) community pharmacies, is a growing public health concern. An educational Patient Safety Card was developed and piloted to see if it nudged customers into the safe and appropriate use of OTC codeine. Exploratory analysis was conducted by (i) recording quantitative interactions for people requesting OTC codeine in community pharmacies; and (ii) a web-based pharmacy staff survey. Twenty-four pharmacies submitted data on 3993 interactions using the Patient Safety Card. Staff found the majority of interactions (91.3%) to be very or quite easy. Following an interaction using the card, customers known to pharmacy staff as frequent purchasers of OTC codeine were more likely not to purchase a pain relief medicine compared to customers not known to staff (5.5% of known customers did not purchase any pain relief product versus 1.1% for unknown customers (χ2 = 41.73, df = 1, p < 0.001)). These results support both the use of a visual educational intervention to encourage appropriate use of OTC codeine in community pharmacy and the principles behind better self-care.