A similar behaviour was observed in samples of amorphous API carbamazepine (C 15 H 12 N 2 O), which were exposed to a 1.0 THz beam, again chosen due to the resonance found in the crystalline spectrum. In the absence of any external perturbation, carbamazepine regularly crystallises on heating in the Form III polymorph . However, upon exposure to the FLARE terahertz beam, the crystallised region within the focus only contained Form I, while the edges of the sample, which were in contact with the copper sample holder that was subsequently heated while exposed to FLARE to in an attempt to speed crystallisation, contained the expected Form III. These results strongly indicate that the intense terahertz radiation produced by FLARE is capable of inducing crystallisation, as well as preferentially promoting par- ticular polymorphic forms. Detailed information can be found in the ESI.