Korean skincare brand numbuzin will release a new intensive spot-care item, No. 5 Shiratama Glutathione C Retinal Shot, in advance sale at the numbuzin official shop on Qoo10 from Sunday, November 1, 2026. The 20ml product has a reference price of ¥2,700 (tax included).
The new item joins the "No. 5 Shiratama※3 Glutathione※4 C" (5番 白玉グルタチオンC) series, a popular radiance care※2 line whose cumulative sales have passed 64 million units※1. It combines retinal※5 at 0.1%, glutathione※4 at 5,000ppm, and niacinamide※6 at 5%.
※1 Cumulative sales volume of the numbuzin No. 5 series over the most recent two and a half years. Aggregation period: January 2024 to August 2026. Based on the company's own research.
※2 Moisturizing the skin and preventing dullness caused by dryness.
※3 A bright skin impression achieved through moisturizing effects.
※4 Glutathione (skin-conditioning ingredient)
※5 Retinal (skin-conditioning ingredient)
※6 Niacinamide (skin-conditioning ingredient)
Background
With July and August※7, the months when UV rays are strongest of the year, now past, it is a season when dullness※8 and a lack of firmness become easier to notice.
numbuzin developed the new item by combining retinal※5, an ingredient attracting attention in skincare, with the long-selling "No. 5 Shiratama※3 Glutathione※4 C" series, a flagship of the brand. The aim is to provide radiance care※2 and firmness care in a single tube.
※7 Based on the Japan Meteorological Agency's press release of July 20, 2005, "Information on Ultraviolet Rays Using the UV Index" (「UVインデックスを用いた紫外線に関する情報について」).
※8 Dullness caused by dryness.
Product Features
Point 1: Fresh Until Just Before Use — Double-Action, High-Concentration Capsules That Pop Open the Instant They Are Applied※9
The product uses a dual capsule system※9. Two ingredients with different characteristics, retinal※5 and glutathione※4, are sealed in separate capsules and kept in a stable state until just before they touch the skin.
The ingredients are delivered in a fresh state to the stratum corneum.
※9 A formula in which retinal (skin-conditioning ingredient) and glutathione (skin-conditioning ingredient) are each encapsulated.
Point 2: Intensive Care Aimed at Areas of Concern — A Double Approach to Radiance※2 and Firmness Care at Once
Released as part of the No. 5 Shiratama Glutathione C line, which specializes in radiance care※2, this product is an intensive care item. In addition to radiance care※2 for areas of concern, it provides firmness care.
It contains ingredients that support radiance care※2, including niacinamide※6 at 5%, glutathione※4 at 5,000ppm, and vitamin C※10. These approach dullness caused by dryness and uneven skin texture, leading to a bright, dewy skin impression.
With retinal※5 at 0.1%, the product approaches skin firmness as well as radiance care※2. It is also recommended for intensive care of areas where a lack of firmness is a concern, such as around the eyes and mouth.
The product also contains 44% vitamin tree water※11. Its dewy, gel-like texture moisturizes the skin and leaves it smooth.
※10 Ascorbic acid (skin-conditioning ingredient)
※11 Hippophae rhamnoides water (skin-conditioning ingredient)
Tested in Various Ways※12: Not Just for the Whole Face — Intensive Care for Dullness※8 and Wrinkle Spots of Concern
The tube type is designed so that the product can be applied precisely to areas of concern. In addition to the eyes and mouth, it can be used on areas where dullness from dryness tends to be noticeable, such as the neck and underarms.
Various tests have been completed※12 on firmness concerns around the eyes, neck, and nasolabial folds, and on dullness※8 around the eyes, underarms, and other areas. It is a "double-approach formula" for radiance※2 and firmness care.
※12 The company conducted improvement tests on dark circles, spots and freckles, and darkening of the underarms (results vary from person to person).
Point 3: Powerful Care, Gentle on the Skin — Low-Irritation Design※13
Skin low-irritation tested
The product contains the moisturizing ingredient panthenol, which cares for the dryness often felt when using retinal.
It keeps the skin in a comfortable, moisture-rich condition.
※13 Low-irritation tested. This does not mean that irritation will not occur for everyone.
Product Overview
| Item | Details |
|---|---|
| Product Name | No. 5 Shiratama Glutathione C Retinal Shot (5番 白玉グルタチオンCレチナールショット) |
| Volume | 20ml |
| Price | ¥2,970 (tax included) |
| Release Date | Sunday, November 1, 2026 |
| Where to Buy | numbuzin official shop on Qoo10 https://www.qoo10.jp/shop/numbuzin |
