Yes, you can use both in one routine, but most people separate them. Vitamin C in morning skincare and peptides at night is the simple way to do it. Low pH vitamin C may break peptides down, and copper can react with ascorbic acid.
Why are peptides and vitamin C kept apart?
The reason is pH. The Ordinary advises using direct acids and L-ascorbic acid in separate routines from peptides, because their low pH can raise the risk of peptide breakdown.
Copper peptides add a second reason, as copper and ascorbic acid can react with each other in solution. We found no strong human study measuring the effect of using them at different times of day, so this is sensible caution and not proven harm.
What is the easiest routine with both?
Split them by time of day, which takes no extra effort.
| Time | Step 1 | Step 2 | Step 3 |
|---|---|---|---|
| Morning | Cleanser | Vitamin C | Sunscreen |
| Night | Cleanser | Peptide serum | Moisturiser |
Does every vitamin C product need separating?
Not always. Gentler forms of vitamin C sit at a higher pH than pure L-ascorbic acid. The label may list them as ascorbyl glucoside or sodium ascorbyl phosphate. Even so, splitting them remains the easiest rule to follow.
What if your skin reacts?
Stop both, then bring back one product at a time with a few days between. This shows you which product is the cause. Our routine guide covers the order of each step.
Common questions
Can I use niacinamide with peptides?
Yes. Niacinamide and peptides are commonly used together and our PDRN Peptide Serum contains both. Stop if your skin stings or flushes, and reintroduce one product at a time.
Can I use peptides with AHA or BHA acids?
Keep them apart if you can. Use acids on a different night from your peptide serum, since low pH products can affect peptide stability and may increase irritation on the same evening.