Yokukansan is a classical Japanese Kampo herbal formula composed of seven botanicals that work together to calm the nervous system. It has been prescribed in Japan for over 400 years, originally for childhood irritability and nervous conditions, and is now widely studied and used for behavioral symptoms in dementia. It is one of the most clinically researched Kampo formulas in modern Japanese medicine.

Yokukansan is thought to gently modulate the brain's glutamate and serotonin systems, both of which play key roles in mood, agitation, and sleep. The Uncaria hook component contains alkaloids believed to reduce overactive nerve signaling, while the whole formula together appears to calm stress responses without heavy sedation. It may also support healthy cortisol regulation, helping the body respond to stress more smoothly.

In Japan, Yokukansan is most commonly dispensed as standardized granule powder (TJ-54 by Tsumura), which dissolves in warm water and is taken two to three times daily. Tablet forms are available for convenience. Traditional decoctions involve boiling the raw herbs. Outside Japan, liquid extracts and capsules are increasingly available through integrative health providers.

• Dementia agitation and aggression
• Anxiety and irritability
• Sleep problems and insomnia
• Behavioral symptoms in Alzheimer's disease
• Lewy body dementia symptoms
• Autism-related irritability (children)
• Stress and nervous tension
• Depression with anxiety features
• Schizophrenia-related anxiety (adjunct)
• Borderline personality irritability

• Escalation of mild behavioral symptoms to severe agitation in dementia patients
• Medication overload — its use may reduce the need for antipsychotics in dementia care

Yokukansan is a multi-herb formula — its active compounds are not found in everyday foods in meaningful amounts. To support the same calming, stress-regulating pathways, focus on: green tea (contains L-theanine for calm focus), dark leafy greens and legumes (magnesium for nerve function), fatty fish like salmon or mackerel (omega-3s that support brain and mood), fermented foods like kefir and miso (gut-brain axis support), and foods rich in B vitamins such as whole grains, eggs, and sunflower seeds (nervous system support). Limiting caffeine, alcohol, and ultra-processed foods also supports the calm nervous system state Yokukansan promotes. Supportive foods to avoid or limit: excess caffeine (heightens agitation), alcohol (disrupts sleep and mood regulation), and high-sugar diets (worsen stress reactivity and neuroinflammation).

• Low potassium (hypokalemia) — especially with prolonged use, can cause muscle weakness or cramps
• Elevated blood pressure — related to the licorice component
• Mild fluid retention or edema
• Occasional digestive upset or loose stools
• Rare skin reactions or mild rash
• Drowsiness in sensitive individuals (generally mild)

• Recommended daily: 7.5 g/day of standardized granule powder (TJ-54), typically divided into 2–3 doses; tablet equivalents vary by manufacturer — follow product labeling
• Best time of day: Traditionally taken 2–3 times daily with meals; one dose before bed is often recommended for sleep and nighttime agitation
• With or without food: Traditionally taken just before or with meals to support digestion and absorption; taking with warm water or warm tea is the classical practice
• Time to effect: Behavioral and agitation benefits often seen within 2–4 weeks; sleep improvement may occur within days to 1–2 weeks
• How long to take it: Clinical trials have run 4–12 weeks; long-term use is practiced in Japan under medical supervision. Due to the licorice component, potassium levels and blood pressure should be checked if using daily beyond 8 weeks. No standard cycling protocol exists — duration is typically guided by clinical response.