I’m Irene, a Taiwanese pharmacist working in a Japanese drugstore. When choosing Pastime pain-relief patches, check the size as well as “LX8.1.” The regular and large versions are both applied once daily, but their daily patch limits differ. Here is how to identify the LX8.1 Premium products launched in 2026 and keep pack size, patch size and dosing separate.
- Identify LX8.1 Premium by its full name
- What is it used for?
- Who must not use it?
- How to apply it: three practical steps
- What does “8.1” mean?
- Do not add another topical pain medicine
- Side effects: when to stop
- Do not borrow directions from LX, LX Premium or ZX
- Storage and travel
- A useful question at a Japanese drugstore
- Official sources
Identify LX8.1 Premium by its full name
Yutoku Pharmaceutical launched パスタイムLX8.1プレミアム and パスタイムLX8.1プレミアム大判 on March 17, 2026. Both are Japanese Class 2 OTC medicines sold in resealable medicine pouches. Check LX8.1, PREMIUM and the patch dimensions, rather than relying on the gold packaging.
Regular: 7 × 10 cm
The top-right panel says 7 cm × 10 cm. Yutoku currently lists packs of 7, 14 and 21 patches; the photograph shows the seven-patch pack. All three pack sizes contain the same size of patch and have the same daily limit.
Apply once daily. Maximum: four patches in total per day across the body.
Large, or 大判: 10 × 14 cm
Look for 大判 in white on black beside PREMIUM and 10 cm × 14 cm at the top right. The current official listing is a seven-patch pack. Although both photographs show seven-patch packs, each large patch has twice the surface area of a regular patch.
Apply once daily. Maximum: two patches in total per day across the body.
Do not add the two limits together. Four regular patches plus two large patches is not an authorized daily dose. These leaflets do not give a mixed-size regimen, and they prohibit using other topical pain-relief/anti-inflammatory medicines during treatment. Ask a pharmacist before switching or combining products.
What is it used for?
The Japanese indications cover lower-back pain, shoulder pain associated with stiffness, joint and muscle pain, tenosynovitis affecting the hand or wrist, elbow pain such as tennis elbow, bruises and sprains. It provides temporary symptom relief. Use it only when symptoms are present: it does not treat the underlying disease causing pain or swelling and is not a preventive patch to put on before a long walk.
Who must not use it?
- Children under 15. Cutting a patch smaller does not create an approved children’s dose.
- Anyone who has had an allergic reaction to this product or an ingredient.
- Anyone who has had asthma triggered by this product, another fever/pain medicine, a cold medicine, or a topical pain-relief/anti-inflammatory medicine. This restriction still matters when a medicine is applied to the skin.
Do not apply around the eyes, to mucous membranes, eczema, contact dermatitis, wounds, athlete’s foot or ringworm, or an area with pus.
Ask a doctor, pharmacist or Japanese registered OTC seller before use if you are under a doctor’s care, have had allergic reactions to medicines or other substances, are pregnant or may be pregnant, are an older adult, or have been diagnosed with bronchial asthma. Pregnancy requires advice even though the medicine is topical. The prohibition for medicine-triggered asthma still applies.
How to apply it: three practical steps
Remove the protective film and apply to the affected area. The daily maximum is four regular patches or two large patches. Count every patch used across all areas of the body that day; the limit is not a separate allowance for each painful area.
The pouch’s “24時間持続” wording describes sustained action. It is not an instruction to tolerate irritation for 24 hours. Do not increase the number of patches or repeatedly replace them during the day because the cooling sensation has faded.
Stop if symptoms have not improved after five to six days, and take the leaflet to a doctor, pharmacist or registered OTC seller. Another condition may be responsible. Do not use continuously for two weeks or longer. If pain persists, stop and see a doctor. A suspected side effect needs attention sooner, not on day five.
What does “8.1” mean?
Both sizes have the same active-ingredient concentrations. These are the amounts in 100 g of the medicated adhesive, not in one patch and not a quantity to apply:
- Loxoprofen sodium hydrate 8.10 g, equivalent to 7.14 g anhydrous loxoprofen sodium: a nonsteroidal anti-inflammatory drug, or NSAID.
- l-Menthol 3.50 g.
- Tocopherol acetate 2.30 g, a vitamin E derivative.
- Glycyrrhetinic acid 0.10 g.
A regular patch contains 0.7 g of medicated adhesive; a large patch contains 1.4 g. The large patch has more adhesive and a larger area, not a higher concentration. “8.1” does not mean 8.1 mg per patch, and the number alone does not establish how much better it relieves pain than another product.
If you have ingredient allergies, check the inactive ingredients too. Yutoku lists styrene-isoprene-styrene block copolymer, polyisobutylene, alicyclic saturated hydrocarbon resin, hydrogenated rosin glycerol ester, liquid paraffin and dibutylhydroxytoluene, plus three other ingredients not individually named in this public list. Ask the manufacturer or a pharmacist if a specific ingredient needs checking.
Do not add another topical pain medicine
Do not use other topical pain-relief/anti-inflammatory medicines while using this product. That includes other patches, creams or gels with the same purpose. A different brand or a different application site does not remove this restriction. If you also take oral painkillers, cold medicines or prescription medicines, show their names and ingredients to a pharmacist first. Do not stop prescribed treatment on your own.
Side effects: when to stop
- Stop immediately and seek professional advice for rash, redness, itching, swelling, stinging or burning, contact dermatitis, blisters, bruising or increased skin pigmentation; stomach discomfort or pain in the upper central abdomen; or fluid retention. Take the leaflet with you.
- Diarrhea or loose stools: stop and seek advice if these persist or worsen.
Do not borrow directions from LX, LX Premium or ZX
Japanese stores also carry Pastime LX, Pastime LX Premium without “8.1,” and ZX/ZX-L products. Read the full name rather than treating “Pastime” or similar packaging as proof of the same medicine. The patch limits, adhesive amounts and ingredients in this guide apply only to LX8.1 Premium regular and large patches. Use each other product’s own leaflet. If your pouch says ZX or ZX-L, see the separate Pastime ZX vs ZX-L guide to sizes, daily limits and application.
Storage and travel
Keep in a cool, dry place away from direct sunlight and out of children’s reach. Leave unused patches in the original pouch and reseal it firmly after opening. Do not transfer them to another container or travel bag. Do not use after the expiry date; use promptly after opening the foil pouch. The leaflet does not set a fixed number of months after opening. Finishing a pack is not a reason to extend treatment.
A useful question at a Japanese drugstore
This means: “I’m looking for Pastime LX8.1 Premium. Are the daily patch limits different for the regular and large sizes?” Also tell the pharmacist your age, where and how long it has hurt, any allergies or asthma history, and what medicines you use.
Official sources
Checked November 10, 2026. This guide concerns products sold in Japan and provides identification and general medicine information, not individual diagnosis or treatment. Read the complete instructions supplied with your product.
- Yutoku Pharmaceutical: regular LX8.1 Premium product information and package photograph
- Yutoku Pharmaceutical: large LX8.1 Premium product information and package photograph
- PMDA: regular-size Japanese leaflet linked by the manufacturer
- PMDA: large-size Japanese leaflet linked by the manufacturer
- Yutoku Pharmaceutical: March 17, 2026 launch announcement
