Additional Listing

GW Pharmaceuticals PLC

EXERCISE OF WARRANTS

Porton Down, UK, 16 January 2014: 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 1,888,480 new ordinary shares of 0.1p each.

These new ordinary shares are being issued pursuant to the exercise of warrants held by funds managed by Great Point Partners. The warrants represent 50% of the warrants issued to Great Point Partners in August 2009 which were due to expire in August 2014.

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

It is expected that admission will become effective on 22 January 2014.

Enquiries:

GW Pharmaceuticals PLC Tel: +44 (0)1980 557 000

Adam George, Company Secretary

Peel Hunt LLP (Nominated Adviser) Tel: +44 (0)207 418 8900

James Steel/Oliver Jackson