Neoday
ネオデイ
Designated Class 2 — Use with special caution
Abuse-Prevention Designated · 指定濫用防止医薬品
Drug Type
Sleep aid (antihistamine)
Form
Tablets
Indication
To alleviate the following symptoms because of temporary insomnia: trouble falling asleep and shallow sleep
Active Ingredients (per 2 tablets)
• Diphenhydramine hydrochloride 50mg
Inactive Ingredients
Lactose, hydroxypropylcellulose, anhydrous silicic acid, croscarmellose sodium, magnesium stearate, hypromellose, sugar, titanium oxide, carnauba wax
Instructions for Use
| Age | Dose per use | Times per day |
|---|---|---|
| Adults (15 years and older) | 2 tablets | Once daily |
| Under 15 years | Do not use | — |
- ✕Do not take if you are or may be pregnant, or if you have chronic insomnia or have been diagnosed with insomnia.
- ✕Do not use with other agents for anesthesia and sedation, cold medications, antipyretic-analgesic medications, antitussive-expectorant medications, or any oral medication containing antihistamines (including rhinitis medications, motion sickness medications, and anti-allergic medications).
- ⚠Consult a physician, pharmacist, or registered salesperson before use if: you are currently receiving treatment from a physician; you are an elderly person; you have a history of allergic reactions to drugs; or you have dysuria, glaucoma, or prostatic hypertrophy.
- ✓Take 2 tablets at bedtime with cold or lukewarm water when you have difficulty falling asleep or experience shallow sleep.
- ✕Do not take at any time other than bedtime.
- ✕Children under 15 years of age must not take this medication.
- ✓Take only when needed for occasional sleeplessness. Do not use continuously.
- ✕Do not drink alcohol before or after taking this medication.
- ✕Do not operate vehicles or machinery after taking this medication.
- ✕Do not take if you are breast-feeding, or stop breast-feeding if you take this medication.
Abuse-Prevention Designated Medicine 指定濫用防止医薬品
- Purchase is limited to 1 unit per person per transaction, both in-store and online
- A pharmacist or registered salesperson must confirm appropriate use before the sale is completed
- Additional restrictions apply for buyers under 18
- Do not exceed the prescribed dose — taking more than directed may cause serious adverse effects
Additional Information
You may feel sleepy even on the following day or may feel dullness.
Sources & Documents
- Japanese product page
- English PDF
- Japanese PDF
- Last verified: May 23, 2026
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For informational purposes only. Always consult a doctor or pharmacist before taking any medication.