Block Listing Application

GW Pharmaceuticals PLC ("GW Pharmaceuticals")

BLOCK LISTING APPLICATION

Cambridge, UK, 1 June 2015: GW Pharmaceuticals (AIM: GWP, NASDAQ: GWPH) hereby provides notification that application has today been made to the London Stock Exchange for admission to trading on AIM of a block of 1,500,000 new ordinary shares of 0.1p each.

1,000,000 of these new ordinary shares will be issued from time to time pursuant to the exercise of employee share options under the GW Pharmaceuticals Long Term Incentive Plan 2008.

500,000 of these new ordinary shares will be issued from time to time pursuant to the exercise of employee share options under the GW Pharmaceuticals Unapproved Share Option Scheme 2001.

On exercise the shares will be issued credited as fully paid and will rank pari passu with the existing ordinary shares in issue.

It is expected that such admission will become effective on 5 June 2015.

For further information, please contact:

GW Pharmaceuticals PLC +44 (0)1980 557 000

Adam George, Company Secretary

Peel Hunt LLP (Nominated Adviser)

James Steel / Oliver Jackson +44 (0) 20 7418 8900