Active ingredients: used well, or used too much?

Retinol, AHA, BHA, Vitamin C and Niacinamide are the most researched and most widely used actives in modern skincare. But how well they work depends entirely on how you use them, not on how many you use.

Why "more" isn't always better

One of the most common misconceptions in skincare is that the more actives you use, the faster your skin will improve. In reality, each active works on a specific biological mechanism, and when that mechanism is overstimulated or conflicts with another, the result is a weakened skin barrier, accumulated irritation, and skin that is actually worse than before you started.

At Claire, we regularly see skin that has been damaged by too many of the right actives, used in the wrong order, at the wrong frequency, or on the wrong skin type.

The four most important actives and how to use them well

Niacinamide: the easiest active to use, and the most misunderstood

Niacinamide (Vitamin B3) is known as the "peaceful" active: the least irritating, and usable morning and evening. But there is one important caveat that's often overlooked: high-concentration niacinamide (above 10%) can cause temporary flushing in some people due to histamine release. Starting at 4–5% is the ideal starting point for most skin types.

Niacinamide is especially valuable while restoring the skin barrier: it controls excess oil, stimulates ceramide production and has a mild anti-inflammatory effect. That's why Claire often recommends niacinamide as a first step before introducing stronger actives.

Combinations to avoid

• Retinol + AHA/BHA in the same routine: All three of these actives increase skin sensitivity. Using them together causes serious irritation and quickly damages the skin barrier.
• Vitamin C + Niacinamide in the same step: Chemical theory suggests they can form nicotinic acid, which causes redness. In practice, the risk is low with modern formulations, but to be safe it's best to use them at different times.
• Retinol + Benzoyl Peroxide: Benzoyl peroxide oxidises and deactivates retinol. These two actives cancel each other out completely.
• AHA + Vitamin C in the same step: the very low pH of AHA can deactivate Vitamin C. If you want to use both, leave at least 15–20 minutes between them.

A safe way to introduce actives

Rather than using many actives at once, the scientific approach is to introduce one active at a time, with a long enough adjustment period:

• Weeks 1–2: Niacinamide (building the skin barrier)
• Weeks 3–4: Add AHA or BHA 2x/week
• Weeks 5–6: Introduce Vitamin C in the morning
• Weeks 7–8: Retinol 1x/week in the evening
• Increase frequency gradually once your skin has adjusted, watching its response throughout

When should you leave it to a professional?

Active ingredients in at-home skincare have limits on concentration and depth of action. For conditions such as deep pigmentation, recurring inflammatory acne or visible ageing, in-clinic treatments with higher concentrations, controlled by professionals, give faster and safer results than any OTC product.

At Claire, Facials and DA KÝ™ treatments use clinical-grade active ingredients, adjusted session by session based on how your skin actually responds, not on a fixed formula.