The short version
- A water-based serum with 11 listed ingredients, niacinamide second after water; 30 ml (1 fl oz) dropper bottle.
- $5.40 on Amazon on Sep 30, 2026, about $0.18 per ml, sold by Amazon.com; the listing marks it non-returnable.
- The brand advises keeping it and vitamin C products in separate routines, and suggests a patch test before first use.
Not a cleanser; it goes on clean skin.
The optional serum step, right after cleansing.
Not a moisturizer; one goes on over it.
No SPF; sunscreen still goes on last in the morning.
Morning and evening, per the brand's directions.
The full label
We printed the list from The Ordinary's U.S. product page, read on Sep 30, 2026. The Amazon listing's ingredient text is identical, word for word. The brand notes that formulas are updated from time to time, so the box in hand may differ from the page.
Aqua (Water), Niacinamide, Pentylene Glycol, Zinc PCA, Dimethyl Isosorbide, Tamarindus Indica Seed Gum, Xanthan Gum, Isoceteth-20, Ethoxydiglycol, Phenoxyethanol, Chlorphenesin.
Marked = key ingredient discussed below11 ingredients listed
| Key ingredient | What it is | What to know |
|---|---|---|
| Niacinamide | Vitamin B3 (nicotinamide) | The "10%" in the name. Lab and small human studies link topical niacinamide to changes in surface lipids and oil measures [2][3], mostly at lower strengths than 10%. |
| Zinc PCA | Zinc salt of pyrrolidone carboxylic acid | The "1%". The brand describes it as helping balance oil and as a humectant; we found no independent study of this formula to cite. |
| Pentylene Glycol | Solvent and humectant | Third on the list; helps carry the other ingredients and hold water in the serum. |
What the evidence and the label claims say
What the numbers mean. The name is the brand's way of stating strengths: 10% niacinamide and 1% zinc. The listing's ingredient graphic pairs "Zinc 1%" with "(PCA)", so the 1% refers to zinc PCA, the form on the list. The product page does not say how the percentages were measured (for example, by weight), so we can only report them as the brand states them. The order of the list is consistent with the name: niacinamide sits right after water, and zinc PCA fourth.
What the brand says. The product page describes a water-based, alcohol-free, oil-free and silicone-free serum with a pH of 5.00 to 6.50, and aims it at visible shine, uneven texture and pores [1]. It calls the serum non-comedogenic based on its own 8-week study of 35 people, which is not published on the page. The Amazon title adds a skin-type phrase that we do not repeat; this site does not frame products around skin conditions.
What independent research shows. Niacinamide has a research literature of its own, but the studies are small and rarely match a product like this one. In a lab study using cultured human skin cells, nicotinamide increased the cells' production of ceramides and other surface lipids; the same paper reports that topical application raised ceramide levels in the outer skin layer and lowered transepidermal water loss in dry skin [2]. A separate pair of trials tested a moisturizer with 2% niacinamide: in 100 Japanese adults over four weeks, the niacinamide group had a lower sebum excretion rate than the placebo group, while a 30-person split-face study in white adults found lower casual sebum levels at six weeks but no significant change in excretion rate [3]. Those results come from a 2% moisturizer, not a 10% serum. Nothing here shows what this bottle will do for a given person.
A higher percentage is not automatically better, and the brand itself says to patch test first, stop if irritation occurs and use it only on unbroken skin. The listing also marks the item non-returnable, so a trial bottle you don't get along with stays with you.
Where it goes in a routine
This is the order the brand's directions describe, not an outcome.
Patch test first
The brand suggests applying a small amount to the upper forearm, keeping it dry, and not using the product if redness, burning, itching or irritation appears.
Cleanse
Start with clean skin; see 01 Cleanse.
Apply a few drops
Spread a few drops over the face, morning and evening. Keep vitamin C products for the other routine; the brand says combining them may reduce effectiveness.
Moisturize, then protect
Let it settle, then apply moisturizer. In the morning, finish with a broad-spectrum sunscreen.
Price and where it is sold
On Sep 30, 2026 the Amazon listing for the 30 ml bottle (ASIN B01MDTVZTZ) showed $5.40, about $0.18 per ml ($5.40 per fluid ounce), in stock, shipped and sold by Amazon.com. The listing states "This item is non-returnable." The brand also makes a 60 ml size. See the listing on Amazon (as an Amazon Associate we earn from qualifying purchases).
Who should look elsewhere
- Anyone who has reacted to one of the eleven listed ingredients, or who found niacinamide irritating before.
- Anyone who wants a serum focused on water-binding rather than oil; the Hyaluronic Acid 2% + B5 entry covers that.
- Anyone who prefers to avoid non-returnable purchases.
Sources
- The Ordinary (DECIEM). Niacinamide 10% + Zinc 1% U.S. product page: ingredients, highlights, directions, safety guidance and FAQ. Accessed Sep 30, 2026. link
- Tanno O, Ota Y, Kitamura N, et al. Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids to improve the epidermal permeability barrier. Br J Dermatol. 2000;143(3):524-531. PMID 10971324. link
- Draelos ZD, Matsubara A, Smiles K. The effect of 2% niacinamide on facial sebum production. J Cosmet Laser Ther. 2006;8(2):96-101. PMID 16766489. link
This entry is educational and is not medical advice. Patch test new products, stop using anything that irritates your skin, and ask a dermatologist, pharmacist or other clinician about anything specific to your skin or medications.