Insomnia: Understanding the Basics1,2
What is Insomnia?
Insomnia refers to a condition in which individuals experience difficulty initiating or maintaining sleep, or wake feeling unrefreshed. These sleep disturbances can lead to impairments in concentration, mood, daytime performance, and overall wellbeing.
Pathophysiology
The neurobiology of insomnia is multifaceted, involving neurotransmitter imbalances—particularly gamma-aminobutyric acid (GABA), serotonin, and melatonin. One of the most prominent mechanisms is the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis.
The sleep-wake cycle, also known as the circadian rhythm, is a tightly regulated, endogenous biological process that follows an approximately 24-hour cycle, synchronizing physiological functions with the light-dark environment.
This rhythm is orchestrated by the suprachiasmatic nucleus (SCN) of the hypothalamus, which serves as the master circadian clock.
The SCN receives direct input from retinal photoreceptors via the retinohypothalamic tract, enabling light to reset the clock daily.
In response to the absence of light, the pineal gland secretes melatonin, a neurohormone that promotes sleep onset by binding to MT1 and MT2 receptors in the SCN and other brain regions, thus facilitating the transition from wakefulness to sleep.
Sleep regulation is governed by two main processes:
Process C (Circadian):
Aligns wakefulness and sleep with the external light-dark cycle via the SCN.
Process S (Homeostatic):
Reflects the accumulation of sleep pressure during wakefulness, largely driven by adenosine, which inhibits arousal-promoting neurons and increases sleep propensity.
Stages of Sleep5
Sleep is categorized into non-rapid eye movement (NREM) and rapid eye movement (REM) stages, cycling approximately every 90–120 minutes.
1. NREM Sleep
Constitutes ~75–80% of total sleep and is divided into three stages:
N1 stage:
Description: Light sleep, transition from wakefulness EEG Signature: Low-voltage, mixed frequency Physiological Features:Slow eye movement reduced heart rate
N2 stage:
Description: Stable light sleep EEG Signature: Sleep spindlesK-complexes Physiological Features: Further decline in HR and body temperature
N3 (Slow-wave sleep):
Description: Deep sleep, restorative phase EEG Signature: High-amplitude delta waves Physiological Features: Growth hormone release immunw regulation memory consolidation
NOTE: N3 is most prominent in the first sleep cycles of the night and is crucial for physical restoration.
2. REM Sleep
Accounts for ~20–25% of total sleep.
Characterized by low-amplitude, high-frequency EEG, similar to wakefulness.
Physiological hallmarks:
Rapid eye movements
Muscle atonia
Vivid dreaming
Elevated brain metabolic activity
Fluctuations in heart rate and respiration
REM sleep is particularly critical for emotional regulation, procedural memory, and neuroplasticity.
HPA Axis
When the brain perceives stress, the hypothalamus releases corticotropin-releasing hormone (CRH), triggering the pituitary to produce adrenocorticotropic hormone (ACTH). This hormone stimulates cortisol secretion from the adrenal glands.
Prolonged or exaggerated cortisol release result in:
Alertness
Suppresses deep sleep,
Delays REM onset
that leads to a chronic state of hyperarousal.
Herbal agents like Ashwagandha, Magnolia bark, and Zizyphus spinosa have shown promise in modulating this stress response, helping recalibrate the HPA axis and supporting more balanced sleep patterns.
Prevalence and Risk Factors6,7
Insomnia affects roughly 10–30% of adults, with higher incidence among women, older adults, and individuals with coexisting psychological or medical conditions. Risk factors include excessive stress, irregular sleep schedules, mental health disorders, chronic pain, stimulant use, and poor sleep environments.
Herbal Remedies for Insomnia8,9
Across traditional healing systems and modern evidence-based practices, herbs have been celebrated for their calming and sedative effects. Contemporary research supports the use of specific botanicals that exert anxiolytic, hypnotic, or adaptogenic effects through identifiable active compounds.
Valerian (Valeriana officinalis) contains valerenic acid and valepotriates, which modulate GABA receptors and contribute to sedative effects.
Passion Flower (Passiflora incarnata) offers calming action through flavonoids like vitexin and isovitexin that enhance GABA activity.
Chamomile (Matricaria chamomilla) contains apigenin, a flavonoid that binds to benzodiazepine receptors to exert tranquilizing effects.
Lavender (Lavandula angustifolia) delivers its effects through linalool and linalyl acetate, essential oil constituents known for their mild sedative properties.
Hops (Humulus lupulus) are rich in humulone and lupulone, contributing to GABA modulation and sedative synergy when paired with Valerian.
Lemon Balm (Melissa officinalis) exerts calming action through rosmarinic acid, which increases GABA availability.
Ashwagandha (Withania somnifera), a well-known adaptogen, contains withanolides that help modulate cortisol levels and stress responses.
Skullcap (Scutellaria lateriflora) offers mild sedation through flavonoids like baicalin.
Kava (Piper methysticum) contains kavalactones such as kavain and dihydrokavain, which affect GABAergic transmission, although caution is needed due to potential hepatotoxicity.
Most Common Herbs
| Ingredient | Common Form | Mechanism of Action | Products |
|---|---|---|---|
| Passionflower (Passiflora incarnata) | Extract, capsule, tea | ↑ GABA activity via GABAA receptor modulation | Caruso’s Sleep More, Brauer Sleep, Fusion Sleep |
| Valerian root (Valeriana officinalis) | Root extract, tablet, tea | ↑ GABA release & inhibits breakdown | ValeriCalm, Flordis Re Dormin Forte, Nature’s Own Valerian Forte |
| Chamomile (Matricaria chamomilla) | Tea, extract, capsule | Binds benzodiazepine receptors; anxiolytic | Herbs of Gold Sleep Ease, Brauer Baby & Child Sleep, Nature’s Own Complete Sleep |
| Hops (Humulus lupulus) | Extract, capsule | GABAergic activity; adenosine modulation | Flordis Re Dormin Forte, Caruso’s Sleep More |
| Lemon balm (Melissa officinalis) | Extract, capsule, tea | Modulates GABA & cholinergic transmission | Herbs of Gold Sleep Ease, Caruso’s Stress Clear |
| Lavender (Lavandula angustifolia) | Oil, oral capsule | Serotonin & GABA modulation; anxiolytic | Avanova Lavender Sleep, Kalms Night, BioCeuticals Lavandulex |
| Ashwagandha (Withania somnifera) | Root extract, capsule | ↓ Cortisol; ↑ GABA signaling | Adrenoplex, AdrenoPS |
| Magnolia bark (Magnolia officinalis) | Bark extract | GABAA receptor agonist | Herbs of Gold Sleep Ease |
| Zizyphus (Zizyphus spinosa) | Seed extract | Sedative via GABAergic tone | Oriental Botanicals Sominicalm, BioCeuticals Sleep Complex, Fusion Sleep |
| California poppy (Eschscholzia californica) | Whole plant extract | Mild opioid & GABA agonism | Naturopathica Sleep & Calm |
| Kava (Piper methysticum) | Root extract | GABAA potentiation; MAO-B inhibition | MediHerb Kava, Brauer Sleep Oral Liquid, Thompson’s Kava |
| L-theanine (from green tea) | Amino acid extract | Promotes alpha brain waves; anxiolytic | Blackmores Valerian Forte, BioCeuticals Ultra Muscleze Night |
| Melatonin (plant-based/synthetic) | Prolonged-release tablet | Binds MT1/MT2 receptors; circadian synchronizer | Circadin® (Rx-only), BioCeuticals Liposomal Melatonin Spray, Melatonin by Ethical Nutrients (practitioner only) |
| Glycine | Amino acid | Inhibitory neurotransmitter; reduces core body temperature | BioCeuticals Sleep Eze, Thorne Glycine |
Additional agents include:
California Poppy (Eschscholzia californica): Contains alkaloids such as protopine and allocryptopine that contribute to its sedative and anxiolytic effects.
Zizyphus (Zizyphus spinosa): Rich in jujubosides and spinosin, saponins and flavonoids that exert neuroprotective and sedative effects.
L-theanine (from green tea): Promotes relaxation and reduces anxiety by increasing alpha-wave activity and modulating dopamine and serotonin levels.
Melatonin: A naturally occurring hormone regulating circadian rhythms; available in synthetic or plant-derived form to aid in sleep onset and timing.
Magnolia Bark (Magnolia officinalis): Contains magnolol and honokiol, bioactive compounds that reduce anxiety and promote sleep via GABA receptor activation.
Poria Mushroom (Wolfiporia cocos): A fungus used in Traditional Chinese Medicine (TCM) known for its tranquilizing and diuretic effects. The key bioactive components include pachymic acid and polysaccharides, which support sedation and modulate the central nervous system by reducing anxiety and dampening overactive neural responses.
Albizia Bark (Albizia julibrissin): Also known as the “Tree of Happiness,” its stem bark is rich in saponins and flavonoids, such as julibroside C1, which exhibit anxiolytic and antidepressant-like effects. It has been traditionally used to calm the spirit and promote emotional balance.
Polygala Root (Polygala tenuifolia): Contains senegenin and tenuifolin, compounds known for their neuroprotective and adaptogenic effects. Polygala enhances memory, reduces anxiety, and promotes deep sleep through modulation of cholinergic and dopaminergic systems.
Biota Seed (Biota orientalis): Also known as Platycladus orientalis, this seed extract contains pinolenic acid and lignans that exert mild sedative and hypnotic effects. Commonly used in TCM for treating insomnia and palpitations, it helps nourish the heart and calm the mind.
Schissandra Fruit (Schisandra chinensis): Rich in lignans such as schisandrin and gomisin, which act as adaptogens and help regulate stress response, cortisol levels, and mental clarity. While not a sedative per se, Schisandra enhances resistance to stress and supports restorative sleep patterns indirectly.
These botanicals are often used synergistically, with standardized extracts allowing for reliable dosing in sleep-supportive formulations tailored to improve sleep onset, depth, and continuity.
Adaptogen
Adaptogens are non-toxic substances that enhance the body’s ability to cope with stress by modulating:
HPA Axis Regulation: Reduces overactivation of cortisol release during chronic stress.
Immune Modulation: Helps balance immune responses (immunostimulatory or suppressive).
Neurotransmitter Balance: Influences serotonin, dopamine, norepinephrine, and GABA.
Antioxidant Effects: Reduces oxidative damage caused by chronic stress or inflammation.
Sedative-Hypnotic Herbs
| Herb | Botanical Name | Active Compounds |
|---|---|---|
| Valerian | Valeriana officinalis | Valerenic acid, Valepotriates |
| Passionflower | Passiflora incarnata | Vitexin, Isovitexin |
| Chamomile | Matricaria chamomilla | Apigenin |
| Lavender | Lavandula angustifolia | Linalool, Linalyl acetate |
| Hops | Humulus lupulus | Humulone, Lupulone |
| Skullcap | Scutellaria lateriflora | Baicalin |
| Biota seed | Biota orientalis | Pinolenic acid, Lignans |
| California poppy | Eschscholzia californica | Protopine, Allocryptopine |
Adaptogens & Stress Modulators
| Herb | Botanical Name | Active Compounds |
|---|---|---|
| Ashwagandha | Withania somnifera | Withanolides |
| Schisandra | Schisandra chinensis | Schisandrin, Gomisin |
| Magnolia bark | Magnolia officinalis | Magnolol, Honokiol |
| Zizyphus | Zizyphus spinosa | Jujubosides, Spinosin |
| Polygala | Polygala tenuifolia | Senegenin, Tenuifolin |
| Albizia bark | Albizia julibrissin | Julibroside C1 |
| Poria mushroom | Wolfiporia cocos | Pachymic acid, Polysaccharides |
Anxiolytics
| Herb | Botanical Name | Active Compounds |
|---|---|---|
| Kava | Piper methysticum | Kavalactones (e.g., kavain) |
| Lemon balm | Melissa officinalis | Rosmarinic acid |
| Albizia bark | Albizia julibrissin | Flavonoids, Saponins |
Cognitive Modulators
| Herb | Botanical Name | Active Compounds |
|---|---|---|
| L-theanine | (from Green Tea) | L-theanine |
Circadian Rhythm Modulator
| Herb | Botanical Name | Active Compounds |
|---|---|---|
| Melatonin | Synthetic or Plant-Based | N-acetyl-5-methoxytryptamine |
Regulatory Oversight and Safety10–12
Regulatory Agencies and Frameworks
The approval and distribution of herbal sleep aids are governed by regulatory agencies such as the TGA (Australia), FDA (USA), EMA (Europe), and others. These bodies evaluate safety, efficacy, and labeling standards.
Quality Assurance and Standardization
To ensure consistency, extracts must undergo rigorous quality control. Analytical techniques such as HPLC and mass spectrometry verify phytochemical identity and potency, ensuring that compounds like valerenic acid or apigenin are present in standardized amounts.
Good Manufacturing Practices (GMP)
Manufacturers are required to follow GMP protocols to minimize contamination and ensure accurate dosing. This ensures herbal products maintain therapeutic integrity across production batches.
Risk Assessment and Herb-Drug Interactions
Some botanicals can interact with prescription medications or have dose-related adverse effects. For example, Kava’s link to liver injury has prompted regulatory guidelines. Herbal sedatives may amplify the effects of benzodiazepines or alcohol.
Consumer Education and Transparency
Clear labeling, including scientific and common names, dosage, warnings, and intended use, is mandated. Education campaigns by regulatory bodies also play a role in safe use.
Conclusion
As scientific validation of traditional wisdom continues to grow, herbal extracts remain promising agents in the treatment of insomnia. By targeting neurotransmitter systems and stress-regulation pathways, these botanicals offer a natural alternative or complement to conventional hypnotics. With regulatory structures in place to ensure safety and quality, plant-based sleep formulations are poised to remain integral in the evolving landscape of integrative sleep medicine.