Oral administration continues to be the most common route for drug delivery with the majority of approved medicines being tablets and capsule dosage forms. Standardised pharmacopeial media are typically used to test tablet dissolution in vitro, however patients use non-standard beverages to take with their medicines. Information about the dissolution of drugs in beverages consumed by patients has not been reported in the literature. Our aim was to investigate if the choice of beverage influences the dissolution of common pain relief tablets. The prevalence and type of alternative beverages used by patients to take their tablets was investigated in an online survey. The rate of dissolution of the common pain relief tablets, aspirin and acetaminophen, was measured in 15 different dissolution media including pharmacopeial dissolution media, simulated gastrointestinal fluids, and the common alternative beverages used by patients to take their tablets (including water, tea, coffee, soft drink and beer). The concentration of drug dissolved in each beverage over time was determined using either UV–vis spectroscopy or HPLC. The rate of dissolution of aspirin and acetaminophen tablets was in some cases significantly affected by the composition of the dissolution media. Factors such as mineral content, carbonation, and pH contributed to differences in the rate of dissolution for both aspirin and acetaminophen. The rate of dissolution of aspirin was significantly lower in some beverages compared to pharmacopeial media. When translated to the in vivo setting, these differences have the potential to alter the pharmacokinetics and bioavailability of orally administered medicines and so their efficacy.