Background Plain packaging and minimum pack size legislation for tobacco products was introduced in the UK in May 2016, with a 1-year sell-off period until May 2017, during which both fully branded and plain packs of various sizes were legally available. This study investigates trends in prices of roll-your-own tobacco (RYO) before, during and after implementation of this legislation, and compares trends with those observed in the cigarette market.

Methods We used Nielsen Scantrack data for the period from March 2013 to June 2018 to describe trends in UK inflation-adjusted prices and volumes of both RYO and cigarettes, and linear regression to estimate changes in prices associated with the introduction of plain packaging and the minimum pack sizes of 30 g RYO and 20 cigarettes.

Results In contrast to a downward trend in cigarette sales volumes, RYO volumes rose throughout the study period. By the time plain packs accounted for 75% or more of sales, the average price of products sold in equivalent pack sizes had increased, relative to average prices in the year before implementation and with adjustment for tax changes, from 34.9 to 38.8 pence per gram for RYO (mean difference 4.26, 95% CI 3.99 to 4.53 pence, 12% increase), and from 38.6 to 41.13 pence for cigarettes (mean difference 2.53, 95% CI 2.24 to 2.83 pence, 7% increase) per cigarette.

Conclusions New legislation resulted in higher prices for RYO and manufactured cigarettes. However, sales volumes of RYO continued to increase throughout the study period, perhaps because RYO remains a less expensive means of smoking tobacco.