Lemon verbena for improving sleep Original paper

In this randomized controlled trial, supplementing with lemon verbena improved sleep quality among adults with sleep disturbances.

The effects of a lemon verbena (Aloysia citrodora) supplement on sleep quality.

71 adults (average age of 30) in Spain with poor sleep quality and moderate anxiety.

During this 3-month randomized controlled trial, the participants took 400 mg of lemon verbena (an extract standardized to a minimum of 24% verbascoside and 28% total phenylpropanoids) or a placebo each night, 1 hour before bed.

The participants rated their sleep quality using a Visual Analog Scale (VAS) and completed the Pittsburgh Sleep Quality Index (PSQI) at baseline and on days 45 and 90. The PSQI includes an overall score, as well as subscores for specific outcomes, such as sleep latency, sleep duration, and sleep efficiency.

Wrist-based actigraphy devices were used to assess sleep efficiency, sleep latency, and the amount of time spent awake after sleep onset (based on the number and duration of awakenings).

Anxiety was assessed using the State-Trait Anxiety Index (STAI), which includes questions related to transient anxiety levels (state), as well as baseline anxiety levels (trait). The Perceived Stress Scale (PSS) was used to assess stress levels over the previous month.

Plasma levels of melatonin (in the evening) and cortisol (in the morning) were also measured.

Based on actigraphy data, PSQI, and STAI, the lemon verbena group had the following, compared with the placebo group:

• Better sleep quality on the VAS
• Reductions (improvements) in overall PSQI scores
• Reductions in sleep latency
• Improvements in sleep efficiency
• Less time awake after sleep onset
• Shorter durations during awakenings
• Reduced state anxiety scores

No differences in trait anxiety scores or stress levels on the PSS were observed between the groups.

Evening melatonin levels were higher in the lemon verbena group, but there were no differences in morning cortisol levels between the groups.

This study was funded by the manufacturer (Monteloeder in Spain) of the lemon verbena extract used, and 3 of the study authors were employees of Monetloeder during the study period.