Phototesting involves the controlled exposure of a substance to a light source, typically a simulated sunlight source that emits both UVA and UVB radiation. The test is often carried out using in vitro methods, where the compound is applied to a biological model such as reconstructed human skin. In some cases, in vivo methods may be used, involving the application of the substance to animal or human skin under controlled conditions. The response is then measured and analyzed for any adverse reactions.
