Ingredient Combinations
What to layer together — and what to keep apart
Best Friends: Ingredients That Work Well Together
• Vitamin C + Vitamin E + Ferulic Acid: The gold-standard antioxidant combo. Ferulic acid stabilises and boosts both C and E.
• Niacinamide + Retinol: Niacinamide reduces retinol irritation while both work on different ageing pathways.
• Vitamin C + SPF: Vitamin C boosts SPF protection by up to 4x.
• Hyaluronic Acid + Moisturiser: HA draws water in; moisturiser seals it.
• Retinol + Peptides: Retinol stimulates collagen, peptides provide building blocks.
Use at Different Times: Can Be in Same Routine, Not Same Step
• Retinol + AHA/BHA: Alternate nights. Both are cell-turnover accelerators; using together causes irritation.
• Vitamin C + Retinol: Vitamin C in AM, retinol in PM. Both are pH-sensitive and work best in different environments.
• Benzoyl Peroxide + Retinol: Benzoyl peroxide degrades retinol. Use BP in AM, retinol in PM.
Avoid Completely
• Two retinoids together (retinol + tretinoin, retinol + adapalene) — excessive irritation, no added benefit.
• AHA/BHA + Physical scrub on the same day — micro-tears and barrier damage.
• Benzoyl peroxide + Vitamin C — BP oxidises Vitamin C, rendering it useless.
pH Matters
Vitamin C (L-ascorbic acid) needs pH < 3.5 to penetrate. AHAs/BHAs work at pH 3–4. Retinol works best at pH 5–6. Layering too many pH-sensitive products in one routine can reduce efficacy. Wait 10–15 minutes between different pH products.