The most useful first question is whether you need to drive. Standard Naron tablets, Naron granules and Naron Ace T contain a sedative ingredient and prohibit driving or operating machinery after a dose. Naron m and Ace Premium have different formulas without that ingredient. The word “Premium” alone does not tell you which medicine suits you.
I'm Irene, a Taiwan-born, Japan-licensed pharmacist working in a Japanese drugstore. Let's match the exact Japanese product name to its ingredients before choosing a box.
Current manufacturer pages and linked Japanese leaflets checked on October 13, 2026. This guide compares adult use; the instructions inside your pack still need to be read.
Start with the formula, not the box size
The amounts below are one dose for ages 15 and over, not daily totals. Every row refers to a different product; choose one rather than combining them.
| Product / Japanese name | One dose, age 15+ | Active ingredients in that dose | Practical distinction |
|---|---|---|---|
| Naron m（ナロンm） | 2 tablets | Acetaminophen 300 mg; glycine 300 mg; thiamine nitrate (vitamin B1) 8 mg; riboflavin (vitamin B2) 4 mg | No caffeine or sedative ingredient; acetaminophen-based |
| Naron tablets（ナロン錠） | 2 tablets | Acetaminophen 265 mg; ethenzamide 300 mg; bromovalerylurea 200 mg; caffeine 50 mg | Contains a sedative; no driving after taking |
| Naron granules（ナロン顆粒） | 1 sachet (1.6 g) | Same active ingredients and adult amounts as Naron tablets | Granules to swallow with water; the same driving prohibition |
| Naron Ace T（ナロンエースT） | 2 tablets | Ibuprofen 144 mg; ethenzamide 84 mg; bromovalerylurea 200 mg; caffeine 50 mg | Ibuprofen combination with a sedative; no driving after taking |
| Naron Ace Premium（ナロンエースプレミアム） | 2 tablets | Ibuprofen 150 mg; ethenzamide 500 mg; dried aluminium hydroxide gel 66.7 mg | No caffeine or sedative ingredient; includes a stomach-protecting ingredient |
For a caffeine-free, sedative-free acetaminophen formula, check whether m suits you. For the standard formula, tablets versus granules mainly changes how you take it, not the adult ingredient amounts. Ace T and Premium are both ibuprofen combinations, but their other ingredients differ substantially. More milligrams across different ingredients is not a reliable “stronger versus weaker” ranking.
Premium's stomach-protecting ingredient does not remove ibuprofen's precautions. Do not choose it as a way around a history of ulcers or another reason you have been advised to avoid an anti-inflammatory painkiller. Lack of a sedative ingredient also does not guarantee that dizziness or other side effects cannot occur.
Match the full name to the current package
These manufacturer images identify packages and dosage forms. They are not to scale; the number of tablets pictured in a blister is not a dose.
Taking it: the shared adult rule
For ages 15 and over, take the single dose shown above up to three times a day, leaving at least four hours between doses. Use water or lukewarm water and avoid an empty stomach as far as possible. Do not increase the dose or take another painkiller because relief has not arrived yet.
- Check the full name, age instructions and medicines you have already taken.
- For tablets, push each tablet out of the blister before swallowing. Never swallow the blister sheet. For granules, use the correct sachet amount with water or lukewarm water.
- Note the time of the dose, keep the required interval, and observe the daily limit.
These are not children's doses. Ace T and Premium are not for under-15s. The minimum labelled age is 7 for m, 8 for standard tablets and 1 for standard granules, with different child doses. Do not transfer one variant's age rule to another. Ask a pharmacist about a child, especially with suspected influenza or chickenpox.
Check these before buying
- Do not use any of these if you previously had an allergic reaction to its ingredients, or asthma triggered by a painkiller or cold medicine.
- Do not combine Naron variants, other painkillers, cold medicines or sedatives. Standard tablets, granules and Ace T also prohibit motion-sickness medicines during use.
- Do not drink alcohol before or after taking them. Avoid prolonged use.
- Ask before use if you are receiving treatment, may be pregnant, are older, have a drug-allergy history, or have heart, kidney or liver disease or a history of stomach/duodenal ulcer. Ace T/Premium have additional cautions for lupus, mixed connective-tissue disease and a history of ulcerative colitis or Crohn's disease.
- Ace T and Premium must not be taken within 12 weeks of the expected delivery date. Earlier pregnancy and breastfeeding also require advice before these two products.
Stop and seek advice if symptoms have not improved after five or six doses, not five or six days. Stop sooner for suspected side effects such as a rash, nausea or dizziness. Breathing difficulty, extensive rash with fever, chest pain or sudden difficulty speaking or moving a limb require urgent medical attention; do not keep trying another variant.
Old names and storage can cause confusion
Taisho's current catalogue lists Naron Loxy, Ace R and Naron Medical as products whose production has ended. They are excluded from this current selection. Production of Premium's 12-tablet pack has also ended, with sales to finish when stocks run out; the 24-tablet pack remains a current option. One pack size ending does not mean the whole Premium formula is discontinued.
Keep the original packaging somewhere cool and dry, away from children. For m and Premium, the leaflet specifies use within six months after opening, even if the printed expiry is later. If a granule sachet is divided according to the child instructions, fold the opening closed and use the remainder within two days.
My shelf-check shortcut: exact name → sedative/driving rule → active ingredients → age and health cautions. If an appropriate painkiller you already have covers the need, buying a second Naron variant usually adds confusion rather than a useful extra option.
