terpene science & layering

Before we look at how each essential oils work, it's important to understand what they are made up of. Essential oils contain terpenes and sesquiterpenes, which are a large and diverse class of organic natural chemicals found in many plants. They contribute to how plants smell, taste, their colour and the effects they have on the body when you apply, inhale or eat them.

Lavender oil is popular for its calming, anxiety-relieving properties and gorgeous smell. It is rich in monoterpenes, especially linalool and linalyl acetate. Monoterpene alcohols and esters like this cross into the nervous system through inhalation, sending signals to neurotransmitters. Linalool is the chief calming compound. It is proven to potentiate GABA receptors, which are the primary inhibitory receptors in the central nervous system, helping to control anxiety, stress, and fear. GABA is the same system that sedatives would target.

Linalool inhalation studies on animals showed reduced activity, increased sleep time and decreased anxiety. Linalyl acetate naturally co-occurs with linalool and enhances this effect, increasing calmness, relaxation, and sleep quality. [4]. There are smaller amounts of other calming components naturally found in Lavender, like geraniol, lavandulol, and cineole, which may have mild effects, but linalool/acetate dominate Lavender's sedative profile.

Vetvier, historically named 'the oil of tranquillity', is a complex oil that consists almost entirely of sesquiterpenes and sesquiterpenoids. Its compounds give it an earthy, smoky scent, and it is traditionally recognised for its calming and sedative properties, which are thought to engage the parasympathetic nervous system. Still, modern studies on Vetiver's inhalation effects are not straightforward.

Some research indicates that inhalation of vetiver oil can lead to a decrease in breathing rate, heart rate, and blood pressure, promoting a sense of calmness, and the oral administration of vetiver oil in animal studies has demonstrated sedative and hypnotic effects, comparable to the standard sedative, diazepam.

However, an EEG study in rats found that vetiver oil increased wakefulness and reduced slow-wave (deep) sleep, making them more alert. Human participants performing visual tasks found that exposure to vetiver oil resulted in faster reaction times and stimulated sympathetic nerve activity. It's a contradiction that suggests the impact of Vetiver on sleep needs more research.

Wild Moroccan camomile (Ormenis multicaulis, also known as Cladanthus mixtus) is a powerful, complex oil rich in both monoterpenes and sesquiterpenes. It features many key components, including camphor, 1,8-cineole, farnesene, biabolol, chamazulene and germacrene D. While they all have varying effects, together, they create a powerful oil associated with promoting relaxation and sleep, reducing anxiety, and providing anti-inflammatory and antioxidant effects. In animal models, inhaling camomile oil vapour reduced stress hormone (ACTH) levels. Traditionally and in clinical practice, camomile oils are used as a calming, sleep‑promoting aroma.

Our Deep Sleep collection, which uses our Deep Sleep Functional Fragrance of Lavender, Camomile and Vetivert in all of its products, is designed to help you create a holistic pre-bedtime 'sleep protocol' that works to improve sleep quality. Frequently using it in a routine promotes good sleep hygiene, encouraging consistent timing, reduced mental stimulation, and sensory cues that mark the transition from day to rest. Over time, this simple aromatic ritual can help train the nervous system to associate these soothing scents with relaxation, making sleep not just a habit, but a holistic, sensory experience.

Our nose-brain connection is extremely powerful, and the brain's limbic system, which governs emotion and sleep–wake patterns, links aroma with relaxation cues. By layering scents, we can support calmer days and peaceful nights through both psychological conditioning and physiological modulation. Research shows that repeated exposure to relaxing terpenes before bedtime, especially linalool (lavender) and α-bisabolol (chamomile), can promote parasympathetic activation to help you fall asleep faster. By layering these aromas in sequence, the body receives numerous signals that it's time to unwind: warmth, touch, breath, and scent all converge into one calming ritual.

This Works has demonstrated the powerful effects of our Deep Sleep Functional Fragrance through our multiple independent panels and user studies examining sleep quality.