Hythiol C Plus EX vs Plus 2 vs Whitea Premium: How to Choose in Japan

Sources checked: 7 October 2026

English · 繁體中文

Someone sends you a photo of Hythiol, but the Japanese drugstore shelf has EX, Plus 2 and Premium. Which box are you looking for? Here is the useful starting point: all three provide the same adult daily amounts of L-cysteine and vitamin C. The differences to check are the other active ingredient, the labeled uses and how often you take them.

Irene | A Taiwan-born pharmacist working in Japan
Match the names to the boxes first, and you will not have to guess what EX or Premium means. Let’s find the product you want to compare, then check how to use it. About Irene

This guide compares three Hythiol tablet medicines sold in Japan. All are Class 3 OTC medicines. Chinese shopping lists may call them 白兔美白錠, but the full Japanese name is the safest way to identify the requested product. None is for children under 7; ages 7–14 use a smaller dose than adults.

Find your starting point, then match the Japanese name

If a twice-daily schedule matters to you, compare C Plus EX and Whitea Premium. If someone asked for C Plus 2, seeing EX on the shelf is not a reason to switch their product. Here is what changes beside each photo.

C Plus EX

ハイチオールCプラスEX

A twice-daily option with labeled uses for pigmentation, fatigue and hangovers

Adults take 2 tablets per dose, twice daily. The third active ingredient is calcium pantothenate, 30 mg per day. Look for CプラスEX, rather than relying on the red box alone.

The photo shows the 120-tablet pack: 30 days at the labeled dose for ages 15 and over.

C Plus 2 (sometimes called Plus II)

ハイチオールCプラス2

The named product on a shopping list, or another option with the same labeled uses as EX

Adults take 2 tablets per dose, three times daily. It provides 24 mg of calcium pantothenate per day. Find Cプラス2: the 2 in its name does not mean twice daily.

The photo shows the 180-tablet pack. This is also 30 days at the labeled adult dose.

Whitea Premium

ハイチオール ホワイティア プレミアム

An option focused on pigmentation relief, with vitamin B6 in its formula

Adults take 2 tablets per dose, twice daily. It provides 50 mg of vitamin B6 per day. SSP markets it for darker, faint and persistent spots; that positioning does not establish that it works better than the other two.

The photo shows 120 tablets. Stop and seek advice if there is no improvement after about 1 month. It is not labeled to treat hangovers or general fatigue.

Original product photos: SSP Co., Ltd. Reproduced to identify the names, packaging and pack sizes. Images are not shown at actual relative scale.

The shared ingredients simplify the comparison

At their labeled adult daily doses, all three provide L-cysteine 240 mg and vitamin C 500 mg. Compare daily amounts: EX provides these in 4 tablets, while Plus 2 provides them in 6. They are not the same amount per tablet. SSP describes L-cysteine and vitamin C as acting on excess melanin, while calcium pantothenate or vitamin B6 supports skin turnover. The table shows how those roles are combined in each formula.

EX has 6 mg more calcium pantothenate than Plus 2, a 25% increase in that ingredient. It does not mean pigmentation improves 25% faster. Whitea Premium’s vitamin B6 also does not make an ingredient table a ranking of effectiveness. The more useful shopping questions are which labeled uses you need to check and whether the medicine is taken twice or three times daily.

For fatigue or hangovers, the labels differ

• C Plus EX and C Plus 2: Japanese labeled uses include pigmentation such as spots, freckles and sun-related pigmentation; general fatigue; and hangovers. Their labels also list acne, eczema, hives, contact dermatitis and drug-related skin reactions.
• Whitea Premium: labeled for relief of spots, freckles and pigmentation following sun exposure or contact dermatitis. It also lists prevention of bleeding gums and nosebleeds, and vitamin C supplementation in specified circumstances. Supplying vitamin C during physical fatigue is a different labeled use from treating general fatigue with the C Plus products.

These are the Japanese labeled indications, not a reason to self-treat a new rash or a suspected medicine allergy. A rash that develops after taking these products is itself a reason to stop and seek advice below.

Three details that help when buying for someone else

• Plus 2 is still a current product. SSP began phasing in a new package design from April 2025. An older family photo may therefore look different. Match ハイチオールCプラス2, rather than the background design alone.
• The older C Whitea and Whitea Premium are different names. SSP marks ハイチオールCホワイティア as discontinued and directs customers to C Plus EX. The current ホワイティア プレミアム is a separate product.
• A 30-day supply can contain different tablet counts. At the labeled adult dose, EX 120 tablets, Plus 2 180 tablets and Premium 120 tablets each last 30 days. For price comparisons, divide the actual shelf price by days of supply rather than comparing bottles by tablet count alone.

SSP lists EX in 40-, 120- and 240-tablet packs; Plus 2 in 60, 180, 270 and 360; and Whitea Premium in 120 and 240. Local stock varies.

How to take them: age first, product name second

Take these tablets with water or lukewarm water. The number of tablets per dose is the same across the three products, but the number of doses per day is not. Check the new bottle before following an old routine.

Under 7: do not use any of the three. A parent or guardian must supervise use by children.

They may be taken before or after meals. SSP advises spacing the doses evenly around your routine, and suggests after meals for first-time users or people with sensitive stomachs. Do not take the whole daily amount at once or increase the dose to try to get faster results.

When to stop or check before continuing

• Whitea Premium: no improvement after about 1 month. Stop taking it and take the leaflet to a doctor, dentist, pharmacist or registered OTC medicine seller in Japan.
• C Plus EX and C Plus 2: symptoms do not improve after taking them for a while. Stop and consult a doctor, pharmacist or registered OTC medicine seller. Their leaflets do not turn this into a fixed six-week waiting period.
• A rash, nausea or vomiting after taking the medicine. Stop immediately and seek advice for any of the three. C Plus EX and Plus 2 also list abdominal pain. Stop and seek advice if diarrhea persists or worsens.
• You already take Transino or another pigmentation or vitamin product. Check the full names and ingredients. Do not combine Transino EX with Whitea Premium: the Transino EX manufacturer advises against combinations with vitamin-C-based medicines that duplicate ingredients such as L-cysteine. Taking them at different times does not solve duplication. Have a pharmacist check other combinations before adding them yourself.
• You are having urine or stool tests. Tell your doctor you take a vitamin C medicine, as it may affect test results.

For travel, keep the tablets in their original bottle, tightly closed and away from sunlight, heat and moisture. Do not handle them with wet hands or transfer them to another container. Keep them out of children’s reach. Always check the packaging and leaflet supplied with your own product.

Questions you may still have

Back at the shelf, match CプラスEX, Cプラス2 or ホワイティア プレミアム. Then check the user’s age, daily dosing frequency and pack size. Those details are more useful than choosing by the biggest word on the box.

Also comparing Transino? Start with the right range

• Transino White C Clear vs Premium
• Transino EX and the older Transino II: checks for a melasma medicine

Official sources and photo credits