Headache & Pain Relief Medicine in Japan: EVE, Bufferin, Loxonin Explained

Headache is one of the most common medical complaints among tourists in Japan. A combination of jet lag, unfamiliar food, dehydration from walking, alcohol, and disrupted sleep schedules creates fertile conditions for a headache to hit — often at the worst possible moment.

Japan's OTC painkiller market is both excellent and slightly confusing for international visitors. The range of products is wide, the active ingredients are not always labeled in English, and one of the most effective options — loxoprofen — is not sold OTC in most Western countries, so visitors may not recognize it. This guide maps the landscape clearly.

Japan's Most Popular OTC Painkillers

The Japanese OTC painkiller market is dominated by four main drug categories: ibuprofen, acetaminophen (paracetamol), loxoprofen, and aspirin. Here is how the major brands align with each category:

Ibuprofen-Based (EVE Series)

EVE is manufactured by SS Pharmaceutical (エスエス製薬) and is probably the single most recognized OTC painkiller brand in Japan. The series has several formulations:

• EVE A (イブA): Standard ibuprofen 150mg per tablet. Two tablets = 300mg ibuprofen. Good baseline painkiller.
• EVE Quick (イブクイック): Ibuprofen 150mg per tablet with faster absorption coating. Marketed for rapid onset.
• EVE Quick DH (イブクイック頭痛薬DH): Ibuprofen 150mg + low-dose dihydrocodeine. The "DH" stands for the dihydrocodeine component, which enhances pain relief and suppresses any accompanying cough. Very popular for headaches.
• EVE Fine (イブファイン): Lower dose (65mg ibuprofen), for people seeking a gentler option.

Who should use EVE: Most healthy adults. EVE is a solid all-round painkiller for headache, fever, menstrual pain, and body aches. It is anti-inflammatory, which makes it more effective than acetaminophen alone for pain with an inflammatory component.

Who should avoid EVE: People with stomach ulcers or gastric conditions (NSAIDs irritate the stomach lining); people with kidney disease; those in the third trimester of pregnancy; people taking blood thinners. Take with food if you have a sensitive stomach.

Acetaminophen-Based (Bufferin Series)

Bufferin (バファリン) is the other mega-brand in the Japanese painkiller market, but it exists in two very different formulations that are easy to confuse:

• Bufferin A (バファリンA): Original Bufferin. Contains aspirin (アスピリン) 330mg plus dried aluminum hydroxide gel as an antacid. This is an aspirin product, not an acetaminophen product. Not appropriate for children or teenagers with viral illness (Reye's syndrome risk).
• Bufferin Premium (バファリンプレミアム): The modern formulation. Contains acetaminophen 330mg + ibuprofen 33mg. This is a different product entirely — a combination analgesic that handles both components of pain.
• Bufferin Ace T (バファリンルナi): Acetaminophen 300mg. Pure acetaminophen; safe for most people including those who cannot take NSAIDs.

The acetaminophen formulations (Premium, Ace T) are the safest option for travelers unsure of their health status. Acetaminophen is the global standard for general pain and fever with the best safety profile across the widest range of patients.

Loxoprofen-Based (Loxonin S)

Loxonin S (ロキソニンS) is one of Japan's most discussed OTC painkillers because loxoprofen sodium — its active ingredient — is not sold over the counter in most Western countries. It is available OTC only in Japan, Brazil, and a small number of other markets.

Loxoprofen is a prodrug NSAID (non-steroidal anti-inflammatory drug) that is converted to its active form inside the body. This metabolic conversion means it has less direct gastric irritation than some other NSAIDs — though stomach protection is still advisable for longer use.

Efficacy: Loxonin S 60mg is broadly comparable in potency to prescription-strength ibuprofen doses. Many users find it noticeably more effective than OTC ibuprofen products for headache, dental pain, and menstrual cramps.

Important purchase note: Loxonin S is a Class 1 (第1類) drug. This means it cannot be taken off the shelf — you must approach the pharmacist's counter and request it. The pharmacist will ask a few brief questions (stomach conditions, other medications, pregnancy status) before selling it. This interaction is normal and required by law.

Who should use Loxonin S: Adults with headache, dental pain, menstrual cramp, or musculoskeletal pain who do not have contraindications to NSAIDs.

Who should avoid Loxonin S: Anyone with stomach ulcers, kidney impairment, or taking anticoagulants; pregnant women; people already taking other NSAIDs. Do not combine with EVE or Bufferin A.

The Loxonin S series has expanded to include:

• Loxonin S Plus (ロキソニンSプラス): Added antacid (sucralfate) to protect the stomach
• Loxonin S Premium (ロキソニンSプレミアム): Loxoprofen + antacid + allyl isopropyl acetylurea (mild sedative component for tension headache)

How to Choose the Right One

Use this symptom matrix to select the most appropriate product:

Note on dosing: Japanese OTC products often specify conservative doses. If you are accustomed to taking 400mg ibuprofen (standard US/UK dose), EVE A at 300mg per dose is slightly lower. This is by regulatory design. Follow the Japanese package directions rather than your home-country dose expectations.

Where to Buy

Most OTC painkillers in Japan are Class 2 (第2類) drugs, which can be purchased from the shelf at any pharmacy, drugstore, or convenience store. However, Class 1 products require the pharmacist counter.