Director/PDMR Shareholding

GW Pharmaceuticals PLC ("GW Pharmaceuticals" or the "Company")

NOTIFICATION OF INTERESTS OF DIRECTORS AND CONNECTED PERSONS

Porton Down, UK, 11 June 2010: GW Pharmaceuticals (AIM: GWP) hereby provides notification that the Company has today been notified that on 9th June Dr Geoffrey Guy, a Director and Executive Chairman of the Company, transferred 11,500 ordinary shares of 0.1p each, equating to 0.01% of the issued ordinary share capital of the Company, into his personal pension scheme. Dr Guy also sold 30,000 ordinary shares of 0.1p each, equating to 0.02% of the issued ordinary share capital of the company, at the market price of 115 pence per share.

Subsequently, Dr Guy has today exercised an option to acquire 50,000 ordinary shares of 0.1p each, equating to 0.04% of the issued ordinary share capital at an exercise price of 36.2 pence per share.

Following this notification Dr Guy's beneficial interest has increased to 18,343,952 ordinary shares, amounting to 14.12% of the shares in issue. The total number of shares outstanding in the Company is 129,893,322 ordinary shares of 0.1p each.

For further information, please contact:

GW Pharmaceuticals PLC +44 (0)1980 557 000

Adam George, Company Secretary

Piper Jaffray Ltd (Nominated Adviser)

Neil Mackison/Rupert Winckler +44 (0) 203 142 8700