Cystex
methenamine, sodium salicylate · Tablet · Oral
Active ingredient
Active ingredients (in each caplet) Acetaminophen 500 mg Diphenhydramine HCl 25 mg
Purpose
Purpose Acetaminophen 500 mg ............................................................... Pain reliever Diphenhydramine HCl 25 mg ...............................................Nighttime sleep-aid
Uses
Uses temporary relief of occasional headaches and minor aches and pains with accompanying sleeplessness
Warnings
Warnings Liver warning: This product contains acetaminophen. Severe liver damage may occur if you take more than 4,000 mg of acetaminophen in 24 hours 3 or more alcoholic drinks every day while using this product with other drugs containing acetaminophen Allergy alert: Acetaminophen may cause severe skin reactions. Symptoms may include: skin reddening blisters rash If a skin reaction occurs, stop use and seek medical help right away.
Do not use
Do not use with any other product containing diphenhydramine, even one used on skin with any other drug containing acetaminophen (prescription or nonprescription). If you are not sure whether a drug contains acetaminophen, ask a doctor or pharmacist. in children under 12 years of age if you have ever had an allergic reaction to this product or any of its ingredients
Ask a doctor before use
Ask a doctor before use if glaucoma a breathing problem such as emphysema or chronic bronchitis liver disease difficulty in urination due to enlargement of the prostate gland
Ask a doctor or pharmacist
Ask a doctor or pharmacist before use if you are taking the blood thinning drug warfarin taking sedatives or tranquilizers
When using this product
When using this product do not drive a motor vehicle or operate machinery drowsiness will occur avoid alcoholic beverages
Stop use and ask a doctor
Stop use and ask a doctor if sleeplessness persists continuously for more than 2 weeks. Insomnia may be a symptom of a serious underlying medical illness. new symptoms occur redness or swelling is present pain gets worse or lasts more than 10 days fever gets worse or lasts more than 3 days These could be signs of a serious condition.
Pregnancy or breast-feeding
If pregnant or breast feeding, ask a health professional before use.
Keep out of reach of children
Keep out of reach of children In case of accidental overdose, get medical help or contact a Poison Control Center right away. Prompt medical attention is critical for adults as well as for children even if you do not notice any signs or symptoms.
Directions
Directions do not take more than directed adults and children 12 years and over: take 2 caplets at bedtime. Do not take more than 2 caplets of this product in 24 hours. children under 12 years: do not use
Other information
Other information TAMPER EVIDENT: DO NOT USE IF OUTER PACKAGE IS OPENED OR BLISTER IS TORN OR BROKEN store at 25°C (77°F); excursions permitted between 15°-30°C (59°-86°F) see end flap for expiration date and lot number
Inactive ingredients
Inactive ingredients colloidal silicon dioxide, corn starch, croscarmellose sodium, FD&C blue #2 aluminum lake, FD&C Red #40 aluminum lake, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, povidone, stearic acid, talc, titanium dioxide
Questions?
Questions or comments? 1-844-297-8394
Label text from the FDA structured product label by Clarion Brands, LLC (revised Dec 27, 2025). Long sections are shortened; the complete label is on DailyMed.
Active ingredients
- Methenamine in 3 products
- Sodium Salicylate in 3 products
- Acetaminophen in 1 product
- Diphenhydramine Hydrochloride in 1 product
Cystex NDC products (4)
| NDC | Strength & form | Labeler | Type |
|---|---|---|---|
| 69693-417 | Acetaminophen 500 mg/1; Diphenhydramine Hydrochloride 25 mg/1 Tablet | Clarion Brands, LLC | OTC MONOGRAPH DRUG |
| 69693-518 | Methenamine 162 mg/1; Sodium Salicylate 162.5 mg/1 Tablet | Clarion Brands, LLC | OTC MONOGRAPH DRUG |
| 69693-512 | Methenamine 162 mg/1; Sodium Salicylate 162.5 mg/1 Tablet | Clarion Brands, LLC | UNAPPROVED DRUG OTHER |
| 69693-513 | Methenamine 162 mg/1; Sodium Salicylate 162.5 mg/1 Tablet | Clarion Brands, LLC | UNAPPROVED DRUG OTHER |
Cystex recalls
- D-0471-2022 Feb 9, 2022 · Class II · Terminated
cGMP deviations
Frequently asked questions
What is Cystex used for?
Uses temporary relief of occasional headaches and minor aches and pains with accompanying sleeplessness
Who makes Cystex?
Cystex is listed by 1 labeler in the FDA NDC directory, including Clarion Brands, LLC.
Has Cystex been recalled?
The FDA enforcement database lists 1 recall for Cystex, most recently D-0471-2022 (class ii): cGMP deviations