Patchouli (Pogostemon cablin) has a long history of use in traditional medicine, particularly in Asian cultures, for a variety of purposes including as a relaxant and to promote restful sleep. In aromatherapy, patchouli essential oil is sometimes diffused or added to bathwater with the belief that its earthy, musky scent has calming effects that may help alleviate anxiety and insomnia. Historical texts and folk practices cite patchouli as a sedative, but these uses are rooted in anecdote and traditional knowledge rather than robust scientific investigation.

Scientific studies specifically examining patchouli's effects on sleep or insomnia in humans are extremely limited. A few animal studies and in vitro experiments suggest that patchouli oil and its components (such as patchoulol) may have mild sedative or anxiolytic properties, possibly by influencing neurotransmitter activity (e.g., GABAergic pathways). However, the evidence is preliminary, indirect, and not sufficient to draw firm conclusions regarding its efficacy for insomnia in humans. No major clinical trials or systematic reviews support the use of patchouli for sleep disorders.

In summary, the use of patchouli to support or treat insomnia is primarily justified by traditional and folk practices, with minimal scientific validation. Its effectiveness for this purpose remains unproven according to current evidence.