Chamomile-lavender and vetiver oils linked to fatigue and sleep improvements in intensive care nurses

Fatigue severity on a visual scale fell from 7.5 to 2.0 in the chamomile-lavender group and 7.0 to 2.0 in the vetiver group, compared to 8.0 to 4.0 in placebo (p < 0.001). Sleep quality scores (Pittsburgh Sleep Quality Index) improved from 10.41 to 4.69 with chamomile-lavender and 10.91 to 4.63 with vetiver, versus 10.78 to 6.84 with placebo (p < 0.001). Fatigue scale scores also dropped significantly in both treatment groups (chamomile-lavender: 5.98 to 2.94; vetiver: 5.58 to 2.76) compared to placebo (5.80 to 4.37). Qualitative interviews confirmed nurses reported better sleep onset and deeper relaxation. A key limitation is the single-blind design and lack of objective measures like actigraphy; placebo response appeared substantial, suggesting expectancy may contribute to benefit.

Both active oils outperformed placebo on all three objective measures—fatigue severity, sleep quality, and overall fatigue burden—with effect sizes (f = 0.462) considered medium to large and post-hoc power of 0.984, indicating robust findings. Interestingly, placebo itself produced meaningful improvement (fatigue dropping from 8.0 to 4.0), suggesting ritual and expectation play a role; the active groups still showed superior gains. The study measured only subjective outcomes and single-blind administration, so participants' knowledge of group assignment may have influenced results. Vetiver and chamomile-lavender performed similarly, implying the mechanism may involve the tactile massage, scent exposure, or bedtime routine rather than a specific oil's chemistry. Nurses specifically noted faster sleep onset and less middle-of-night waking. The authors recommend multicentre double-blind trials with actigraphy (wrist-worn sleep tracking) and longer follow-up to confirm durability.