Cannabis as a tea preparation: For this preparation, cannabis flowers are added to boiling water and kept boiling for 15 minutes. Due to the poor water solubility of the cannabinoids and the slow decarboxylation at 100 °C (and thus conversion into the pharmacologically active form), the yield of the psychotropically active delta-9-tetrahydrocannabinol (THC) is only approx. 5%. The yield can be increased by longer boiling time, at 30 minutes it increases by one and a half times.