The use of moist heat (steam) combined with deep conditioning is widely considered by the community to be a superior method for improving hydration and the penetration of active ingredients into the hair fiber.

noli's read

The community strongly converges on a positive opinion, validating this practice as a staple of hair care. From a scientific perspective, the effect of heat (often called 'thermia') on hair is well-documented: heat can induce slight swelling of the cuticle, which theoretically facilitates the absorption of certain components present in masks, as shown by observational studies on hair structure. However, there is no specific RCT (randomized controlled trial) demonstrating that 'steam' provides a benefit superior to simply applying a product under a standard heating cap. The idea that steam significantly 'opens' the pores of the scalp to promote growth is an exaggerated interpretation, as the hair is an inert structure. The practice is therefore technically effective for softening the fiber, but the biological mechanism remains frequently over-interpreted by users. It is important to note that excessive or overly frequent heat can weaken the hair's protein bonds over the long term.

the sources

1. 1r/HaircareScience