X0306 4 2019-01-02 0 0001351288 GW PHARMACEUTICALS PLC GWPH 0001754129 Gover Justin D. SOVEREIGN HOUSE, VISION PARK, HISTON CAMBRIDGE X0 CB24 9BZ UNITED KINGDOM 1 1 0 0 Chief Executive Officer Ordinary Shares 2019-01-02 4 S 0 2400 7.96 D 413285 D Ordinary Shares 2019-01-02 4 S 0 3600 8.14 D 409685 D Ordinary Shares 2019-01-02 4 S 0 1200 8.25 D 408485 D Ordinary Shares 2019-01-02 4 S 0 14220 8.43 D 394265 D Ordinary Shares 2019-01-02 4 S 0 1200 8.52 D 393065 D These ordinary shares are represented by American Depositary Shares of the Issuer ("ADS"). Each ADS represents twelve ordinary shares of the Issuer. The price reported in Column 4 is price per ordinary share ($95.51 per ADS). The price reported in Column 4 is a weighted average price per ordinary share ($97.69 per ADS). These shares were sold in multiple transactions at prices ranging from $97.14 per ADS (or $8.10 per ordinary share) to $97.97 per ADS (or $8.16 per ordinary share), inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is price per ordinary share ($99.00 per ADS). The price reported in Column 4 is a weighted average price per ordinary share ($101.13 per ADS). These shares were sold in multiple transactions at prices ranging from $100.64 per ADS (or $8.39 per ordinary share) to $101.63 per ADS (or $8.47 per ordinary share), inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is price per ordinary share ($102.25 per ADS). /s/ Justin D. Gover 2019-01-04