E-cigarettes are electronic devices that vaporize a liquid solution (e-liquid) to produce vapour, simulating the experience of smoking without the element of combustion. E-cigarettes and e-liquid are an alternative to tobacco, and do not contain any tar, carbon monoxide, or other chemicals found in tobacco smoke.

Similarly, herbal or concentrate vaporizers provide a heat-not-combust alternative, allowing users, including patients, to avoid the potential side effects and drawbacks associated with smoking.