{"product_id":"isntree-hyper-vitamin-c23-serum-20ml-mirai-skin-isntree-hyper-vitamin-c23-serum-20ml","title":"Isntree Hyper Vitamin C23 Serum 20ml","description":"\u003ch2\u003eIsntree Hyper Vitamin C23 Serum: The High-Concentration L-Ascorbic Acid Serum\u003c\/h2\u003e\n\u003cp\u003eMost Korean vitamin C products use stabilized derivatives (ethyl ascorbic, ascorbyl glucoside) to avoid the formulation instability and irritation of pure L-ascorbic acid. Isntree's Hyper Vitamin C23 goes the other direction: 23% L-ascorbic acid, one of the highest concentrations on the Korean vitamin C market, delivered in a compact 20ml bottle with a focused dropper. At $21.07, it's aggressively priced for a 23% vitamin C serum (Drunk Elephant C-Firma 15% is roughly 5x the price).\u003c\/p\u003e\n\u003cp\u003e23% L-ascorbic acid is a clinical-grade concentration. This is not a beginner vitamin C product. Pure L-ascorbic at 20%+ can cause significant stinging, purging, and barrier disruption for users unprepared for it. Isntree positions this as an advanced-user vitamin C, with a shorter expected shelf life than derivative products (L-ascorbic oxidizes rapidly once exposed to air) and clear \"use within 3 months\" recommendation.\u003c\/p\u003e\n\u003ch3\u003eWhat It Does\u003c\/h3\u003e\n\u003cp\u003eL-ascorbic acid at 23% is among the most potent topical antioxidant and tyrosinase inhibitor concentrations available OTC. It directly prevents melanin formation, scavenges free radicals, and supports collagen synthesis. Combined with vitamin E and ferulic acid (typical stabilizers in L-ascorbic formulations), the effect is the gold-standard vitamin C experience. Results are faster than derivative products: visible brightening in 2 to 3 weeks.\u003c\/p\u003e\n\u003ch3\u003eWho It's For\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVitamin C-experienced users:\u003c\/strong\u003e Have tolerated lower concentrations successfully.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModerate to severe pigmentation:\u003c\/strong\u003e Higher concentration for faster results.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-aging advanced routines:\u003c\/strong\u003e L-ascorbic is the gold standard antioxidant.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for sensitive skin first-timers:\u003c\/strong\u003e Start with derivative products first.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBudget-conscious high-concentration seekers:\u003c\/strong\u003e Remarkably affordable for 23%.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eKey Specs\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eVolume: 20ml (small, intentional; L-ascorbic oxidizes)\u003c\/li\u003e\n\u003cli\u003ePrice: $21.07\u003c\/li\u003e\n\u003cli\u003eHero actives: 23% L-ascorbic acid, vitamin E, ferulic acid\u003c\/li\u003e\n\u003cli\u003eTexture: light serum\u003c\/li\u003e\n\u003cli\u003eFragrance: none\u003c\/li\u003e\n\u003cli\u003eShelf life: 3 months post-opening (shorter than derivative products)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow to Use\u003c\/h3\u003e\n\u003cp\u003eAM only (pair with sunscreen; vitamin C boosts SPF efficacy). Apply 2 to 3 drops to clean, dry skin after cleansing. Let absorb 30 to 60 seconds. Follow with moisturizer and SPF50+. Start with every other day for 1 to 2 weeks before daily use to assess tolerance. Store in a cool, dark place; refrigeration extends shelf life. Discard if the serum turns dark orange or brown (oxidation).\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003ch4\u003eWill it sting?\u003c\/h4\u003e\n\u003cp\u003eYes, typically in the first week. Mild tingling is normal; strong burning or redness indicates over-sensitivity. Start with every-other-day application to build tolerance.\u003c\/p\u003e\n\u003ch4\u003eHow does it compare to SkinCeuticals CE Ferulic?\u003c\/h4\u003e\n\u003cp\u003eCE Ferulic is 15% L-ascorbic + 1% vitamin E + 0.5% ferulic, in a clinical-quality formulation, $169 for 30ml. Isntree is 23% L-ascorbic with similar supporting antioxidants, $21 for 20ml. Ingredient quality and stability may favor CE Ferulic; concentration favors Isntree. Cost-per-active strongly favors Isntree. For advanced users confident in their tolerance, Isntree is excellent value.\u003c\/p\u003e\n\u003ch4\u003eWhy such a small bottle?\u003c\/h4\u003e\n\u003cp\u003eL-ascorbic acid oxidizes within 3 to 6 months of air exposure. Small bottles are intentional: finish the product while it's still fresh. Larger L-ascorbic bottles often oxidize before use-up.\u003c\/p\u003e\n\u003ch4\u003eCan I use it with retinol?\u003c\/h4\u003e\n\u003cp\u003eYes, but PM and AM split: retinol PM, C23 AM. Don't stack them same application.\u003c\/p\u003e\n\u003ch4\u003eHow long until results?\u003c\/h4\u003e\n\u003cp\u003eBrightness and glow: 1 to 2 weeks. Visible dark spot fading: 3 to 6 weeks (faster than derivative vitamin C products).\u003c\/p\u003e\n\u003ch3\u003eRelated Products\u003c\/h3\u003e\n\u003cp\u003ePair with Isntree Hyaluronic Acid Daily Sun Gel for morning SPF. For gentler vitamin C, see Isntree C-Niacin Toning Ampoule. Browse Isntree collection, vitamin C skincare.\u003c\/p\u003e\n","brand":"mirai-skin","offers":[{"title":"Default Title","offer_id":51741089595680,"sku":"52944030400884","price":10.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1004\/8333\/4432\/files\/8a9b7ff2d7c16d7f1d087e0ff56d4c34.webp?v=1779694853","url":"https:\/\/usmirai-skin.com\/products\/isntree-hyper-vitamin-c23-serum-20ml-mirai-skin-isntree-hyper-vitamin-c23-serum-20ml","provider":"usmirai-skin.com","version":"1.0","type":"link"}