Director/PDMR Shareholding

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

NOTIFICATION OF INTERESTS OF DIRECTORS AND CONNECTED PERSONS

Porton Down, UK, 2 August 2010: GW Pharmaceuticals (AIM: GWP) hereby provides notification that the Company has today been notified that Dr Geoffrey Guy, a Director and Executive Chairman of the Company, has today exercised an option to acquire 106,167 ordinary shares of 0.1p each, equating to 0.08% of the issued ordinary share capital at an exercise price of 36.2 pence per share.

Dr Guy has further notified the Company that the exercise of options follows the sale by Dr Guy of 4,910 ordinary shares of 0.1p each on 28th July 2010, at the market price of 117.1 pence; 51,910 ordinary shares of 0.1p each on 29th July 2010 at the market price of 116 pence; 2,260 ordinary shares of 0.1p each on 30th July 2010 at the market price of 111.2 pence and the sale of 40,920 ordinary shares of 0.1p each today at the market price of 108.3 pence per share. The total number of shares sold of 100,000 equates to 0.08% of the issued ordinary share capital.

Following these notifications Dr Guy's beneficial interest has increased to 18,351,441 ordinary shares, amounting to 14.10% of the shares in issue.

The total number of shares outstanding in the Company is 130,187,159 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