Ultimate Serum: Layering with Retinol and Vitamin C
By Transformative Science-Based Skincare Australia | Aesthetics Rx® | Published: 2026-10-22
Category: How-to Guides
Learn the correct order to apply Ultimate Serum with retinol and vitamin C for maximum benefits without irritation.
Quick answer
Layer Ultimate Serum after vitamin C in the morning and before retinol at night, always following the thinnest-to-thickest rule.
Why order matters
Vitamin C works best at a low pH, while retinol needs a neutral pH to remain stable. Placing Ultimate Serum between them buffers the skin and prevents one ingredient from deactivating the other. Applying in the wrong order can reduce efficacy or cause irritation.
When to skip a layer
If your vitamin C is a high-concentration L-ascorbic acid serum (pH under 3.5), wait 15 minutes before applying Ultimate Serum. For retinol, a 20-minute wait after Ultimate Serum lets niacinamide settle and avoids flushing. If you have sensitive skin, alternate Ultimate Serum and retinol on different nights.
Step-by-step layering guide
- Morning: Vitamin C → Ultimate Serum → Moisturizer → SPF: Apply vitamin C to clean, dry skin. Wait 1 minute, then apply 2–3 drops of Ultimate Serum. Follow with your moisturizer and sunscreen. Common mistake: applying Ultimate Serum before vitamin C can raise pH and reduce vitamin C absorption.
- Evening: Cleanse → Ultimate Serum → Retinol → Moisturizer: After cleansing, apply Ultimate Serum to damp skin. Wait 20 minutes for niacinamide to absorb, then apply retinol. Finish with a moisturizer to seal. Checkpoint: If you feel stinging, reduce retinol frequency to every other night and keep Ultimate Serum daily.
- Adjust for skin sensitivity: If you are new to retinol or have reactive skin, apply Ultimate Serum in the morning only and use retinol alone at night. Once tolerance builds, reintroduce the evening routine above. Empty
Product facts
- Ultimate Serum: Formulated with Niacinamide, Salicylic Acid, and Botanical Extracts to exfoliate dead skin cells and brighten, smooth. Niacinamide in Ultimate Serum supports the barrier before retinol, while salicylic acid preps skin for vitamin C absorption.
Ultimate Serum
