How to Layer 100% L-Ascorbic Acid Powder with Serums

By The Ordinary | Clinical Formulations with Integrity | Published: 2026-10-25

Category: How-to Guides

Learn the correct order and mixing method for using The Ordinary's 100% L-Ascorbic Acid Powder alongside your other serums for bright, even skin without irritation.

Quick answer

Mix a small scoop of The Ordinary's 100% L-Ascorbic Acid Powder directly into a water-based serum just before application, then layer it after cleansing and before oils or moisturizers.

Why mix instead of applying powder directly

L-Ascorbic Acid is most stable and effective when freshly mixed into a compatible serum. Applying the dry powder directly to damp skin can cause uneven distribution and increase the risk of irritation. By dissolving it in a serum, you control the concentration and ensure even coverage.

Choosing the right serum to mix with

Water-based serums with a low pH (around 3–4) work best because L-Ascorbic Acid requires an acidic environment to penetrate and remain stable. Avoid mixing with oil-based or silicone-heavy products, as the powder won't dissolve properly. The Ordinary's Hyaluronic Acid 2% + B5 is a popular compatible choice.

Step-by-step layering routine

Cleanse and pat dry: Start with a clean, dry face. Do not apply the powder mixture to wet skin, as excess water can dilute the concentration and cause stinging. A common mistake is mixing the powder into a damp face — always pat skin completely dry first.
Mix powder into a serum in your palm: Dispense one pump of your chosen water-based serum into your palm. Add a small scoop (about 1/4 of the provided scoop) of 100% L-Ascorbic Acid Powder. Stir with a clean fingertip until fully dissolved — this takes about 10 seconds. Mix only enough for one use; the mixture oxidizes quickly and cannot be stored.
Apply immediately to face and neck: Press the mixture gently into your skin, avoiding the eye area. Work quickly — the solution remains effective for about 1–2 minutes after mixing. If you feel tingling that doesn't subside within 30 seconds, reduce the powder amount next time.
Wait 60 seconds before next layer: Allow the Vitamin C to absorb before applying your next serum or moisturizer. This prevents pilling and ensures each product works as intended. Skipping the wait time can dilute the Vitamin C and reduce its brightening effect.
Follow with moisturizer and sunscreen (AM only): In the morning, seal everything with a moisturizer and finish with broad-spectrum SPF 30+. Vitamin C makes skin more sensitive to UV, so sunscreen is non-negotiable. For evening use, you can skip sunscreen but still apply moisturizer to support overnight repair.

Product used in this routine

100% L-Ascorbic Acid Powder: The Ordinary's 100% L-Ascorbic Acid Powder offers a customizable concentration of pure Vitamin C to help target visible signs of aging by brightening and evening skin tone. You can adjust the strength from a gentle pinch to a full scoop, making it suitable for both beginners and experienced Vitamin C users.
100% L-Ascorbic Acid Powder