Quick answer

Apply your vitamin C serum first, let it absorb, then finish with a broad-spectrum SPF 50 sunscreen. This order maximizes antioxidant protection and ensures even coverage.

Why order matters

Vitamin C is a water-soluble antioxidant that works best when applied directly to clean skin. Sunscreen, on the other hand, needs to form an even film on top to provide full protection. If you mix them or reverse the order, you may dilute the SPF or block the vitamin C from absorbing.

Layering vitamin C under SPF also boosts the sunscreen's effectiveness—antioxidants help neutralize free radicals that UV rays generate, adding an extra layer of defense beyond the SPF itself.

When to use a moisturizer

If your skin is dry, you can apply a moisturizer after vitamin C and before sunscreen. However, some vitamin C serums, like Paula's Choice 25% Vitamin C + Glutathione Clinical Serum, are lightly hydrating on their own. If you're using a moisturizing sunscreen, you might skip a separate moisturizer to avoid a heavy feel.

Step-by-step layering routine

  1. Step 1: Cleanse and dry: Start with a clean, dry face. Vitamin C absorbs best when skin is free of dirt, oil, and leftover products. Don't apply vitamin C to damp skin—it can dilute the serum and reduce its potency.
  2. Step 2: Apply vitamin C serum: Dispense a few drops of your vitamin C serum (like the 25% Vitamin C + Glutathione Clinical Serum) and press it gently into your face and neck. Allow it to absorb for 1–2 minutes. Wait until the serum feels tacky but not wet—this ensures it's absorbed and won't pill under sunscreen.
  3. Step 3: Follow with moisturizer (optional): If your skin feels dry, apply a lightweight moisturizer. Skip this step if your serum is hydrating enough or your sunscreen is moisturizing. Avoid heavy creams that can interfere with sunscreen's even application.
  4. Step 4: Finish with SPF 50 sunscreen: Apply a generous, even layer of broad-spectrum SPF 50 sunscreen (like Paula's Choice 5% Vitamin C Sheer Moisturizer SPF 50) as the last step of your morning routine. Use about two finger lengths for your face and neck. Don't rub sunscreen in too hard—pat it gently to avoid disturbing the vitamin C underneath.

Products that help

  • 5% Vitamin C Sheer Moisturizer SPF 50: This weightless, multi-active SPF is supercharged with 5% vitamin C and provides broad-spectrum SPF 50. It combines antioxidant protection and sunscreen in one step, ideal for quick mornings or when you want a sheer finish.

    5% Vitamin C Sheer Moisturizer SPF 50

    5% Vitamin C Sheer Moisturizer SPF 50

  • 25% Vitamin C + Glutathione Clinical Serum: This clinical-level serum features 25% vitamin C plus glutathione to visibly improve uneven tone and firmness. It delivers a high dose of vitamin C to tackle stubborn discoloration, and the glutathione helps minimize irritation.

    25% Vitamin C + Glutathione Clinical Serum

    25% Vitamin C + Glutathione Clinical Serum