Tsujimoto Market: Our Guarantees
Description
Spa Treatment eX Real C-Serum — Pure Vitamin C Serum, 18 ml
Overview
A concentrated serum built on ascorbic acid — pure vitamin C, not one of the gentler derivatives. Ascorbic acid is the form with the deepest research behind it for the appearance of dullness and uneven tone, and it is also the least forgiving: it degrades easily and it can sting.
The formula answers the stability problem in the most direct way available, by leaving out water entirely. The base is propylene glycol, so there is nothing for the vitamin C to react with while the bottle sits on your shelf.
Spa Treatment is a professional skincare line from the Japanese manufacturer Wave Corporation, sold mainly through salons and aesthetic clinics in Japan. The eX range is its salon-grade tier. The Japanese name is eX Real C-Serum.
See also our vitamin C and Japanese serums collections.
Key Benefits
- ✓ Pure ascorbic acid, the best-researched form of topical vitamin C
- ✓ Water-free propylene glycol base — the practical reason this stays stable longer than most vitamin C serums
- ✓ Six ingredients, with no fragrance, colourant or alcohol
- ✓ No animal-derived ingredients declared
- ✓ Compact 18 ml bottle, appropriate for an active you use sparingly rather than by the handful
- ✓ Honest dosing guidance, which the original description did not give
Product Details
| Brand | Spa Treatment (Wave Corporation) |
|---|---|
| Country of origin | Japan |
| Japanese product name | eX Real C-Serum |
| Product type | Vitamin C face serum |
| Format | Anhydrous serum, dropper |
| Volume | 18 ml |
| Vitamin C form | Ascorbic acid (pure) |
| Water content | None — anhydrous base |
| Fragrance | None |
| Quasi-drug status | Cosmetic (not a quasi-drug, iyakubugaihin) |
| Vendor | Tsujimoto Market, Kobe, Japan |
Who Is This For?
- Skin that looks dull or uneven in tone and wants a well-evidenced active
- Anyone who has found vitamin C derivatives too mild and wants the pure form
- People willing to wear sunscreen daily — vitamin C and sun protection work as a pair
- Approach cautiously if your skin is reactive or if you have rosacea: pure ascorbic acid is acidic and stings more than derivatives do
- Not for use alongside strong acids or retinoids in the same application
How to Use
- Apply to clean, dry skin. On damp skin an anhydrous serum spreads poorly and stings more.
- Use three to four drops for the whole face — more is not better and increases the chance of irritation.
- Press it in gently rather than rubbing, then wait a minute before your next step.
- Follow with a moisturiser. The propylene glycol base can feel tacky on its own; a cream over the top settles it.
- In the morning, always follow with a broad-spectrum sunscreen.
Frequency: Start with every second evening. Build to once daily if your skin is comfortable, and only then consider morning use.
Full Ingredients
Declared ingredients: propylene glycol, ascorbic acid (pure vitamin C), PEG-12 glyceryl distearate, polyacrylamide, C13-14 isoparaffin, laureth-7.
Note what is absent: water. This is an anhydrous, propylene-glycol-based serum, and that is the reason the vitamin C in it stays stable. Ascorbic acid degrades on contact with water, light and air, which is why so many vitamin C serums lose potency and turn orange. Removing the water is a more meaningful stability measure than any capsule technology described on the packaging.
Origin: no animal-derived ingredients are declared. No fragrance, no colourant, no alcohol.
Ingredient list as declared by the manufacturer. Formulations are occasionally revised, so always read the list printed on the package you receive.
Cautions
- This is pure ascorbic acid and it is acidic. A brief tingle on application is common. Persistent stinging, burning or redness is not — rinse it off and reduce the frequency or stop.
- Introduce it slowly. Every second evening for the first fortnight is a sensible pace, particularly if you have never used pure vitamin C before.
- Do not layer it in the same application as AHA or BHA exfoliants, retinoids or benzoyl peroxide unless a dermatologist has advised it.
- Vitamin C is worth pairing with daily sunscreen, which is where most of its practical benefit for uneven tone comes from.
- Keep the bottle tightly closed and out of the light. If the serum turns deep yellow or brown, the vitamin C has oxidised and it is time to replace it.
- Patch test on the inner forearm before first use, especially if your skin is reactive.
- Discontinue use and consult a doctor if redness, itching, swelling or persistent stinging occurs.
- Avoid contact with the eyes. If the product enters the eyes, rinse immediately with plenty of water.
- Do not apply to broken, sunburned or actively inflamed skin.
- Keep out of reach of children. Store away from direct sunlight and high temperatures.
Package Contents
One 18 ml bottle of Spa Treatment eX Real C-Serum with dropper, in its Japanese retail carton. Labelling is in Japanese.
Shipping & Store Notes
- Ships directly from Japan
- Processing time: 2–6 business days
- Tracking number provided after dispatch
- Import duties and taxes may apply depending on destination country
- Opened cosmetics cannot be returned for hygiene and safety reasons
Authenticity Guarantee
Every product at Tsujimoto Market is sourced directly from Japan and verified for authenticity. We never sell fakes or grey-market goods. Each order is carefully packed in Kobe, Japan and dispatched with full tracking.
FAQ
The old description said the more I use, the better my skin gets. Is that right?
No, and we removed that line. It is the sort of sentence that sells serum and irritates faces. Pure ascorbic acid has a sensible working range on skin, and going above it does not increase the benefit — it increases stinging, redness and the chance you abandon the product altogether. Three to four drops covers a face. If you find yourself using appreciably more than that, the extra is doing nothing except emptying the bottle faster.
Why is there no water in it, and why does that matter?
Because water is what destroys vitamin C. Ascorbic acid in an aqueous solution oxidises steadily — faster with light, air and warmth — and an oxidised vitamin C serum is both less effective and, in high concentrations, more irritating. Formulating without water removes the main route of degradation. The practical trade-off is texture: an anhydrous propylene glycol base feels tackier than a watery serum. Applying a moisturiser over the top solves that.
It stings a little. Should I stop?
A brief tingle in the first minute is common with pure ascorbic acid, especially early on, and it usually settles as your skin adjusts. What is not normal is stinging that persists after a few minutes, burning, or redness that lasts. If you get any of those, rinse the serum off, wait a few days, and either reintroduce it less often or move to a gentler vitamin C derivative. Skin that is already compromised — over-exfoliated, windburnt, mid-flare — should not be the skin you start on.
Should I use it in the morning or the evening?
Either works. We suggest starting in the evening because it lets you learn how your skin responds without also managing sunscreen and make-up over a tacky layer. Once you know you tolerate it, morning use alongside sunscreen is a reasonable routine — the two complement each other. What matters more than the time of day is that you are consistent and that sunscreen is part of the routine either way.
Is this an authentic Japanese product?
Yes. We buy through Japanese distribution channels and ship from our base in Kobe, Japan. We do not sell grey-market or parallel-import stock, and the packaging you receive is the Japanese domestic packaging, with Japanese-language labelling.
