Ingredient Beauty BenefitsPigmentation
Melasma, freckles and marks that stay behind.
Sunscreen
An ingredient class — not a single line on an ingredient list
An Australian trial randomised 1,621 people and followed them 4.5 years. Squamous cell tumour incidence was 39% lower (1,115 vs 1,832 per 100,000); basal cell carcinoma showed no difference. This is one of the few entries on this site carrying strong evidence.
Retinol
Retinol
In a vehicle-controlled trial, 0.4% retinol applied for 24 weeks moved the fine-wrinkle score by −1.64 against −0.08 for vehicle. Thirty-six people, and it was forearms, not faces. In pregnancy, guidance says do not use it.
Niacinamide
Niacinamide
In a 12-week split-face study of 50 people, 5% niacinamide reduced fine lines, yellowing, red blotchiness and pigmented spots. The control was not nothing but the same moisturiser, and the manufacturer paid for the trial.
Salicylic acid
Salicylic Acid
Most acne trials used 30% peels performed in a clinic. What Korea allows as an acne functional claim is 0.5%, and only in rinse-off cleansers. There is a sixtyfold gap between those two numbers.
Vitamin C (ascorbic acid)
Ascorbic Acid
In pig skin, L-ascorbic acid entered only when formulated below pH 3.5, and 20% was the concentration for optimal absorption. Pure ascorbic acid is not among Korea's listed whitening actives; four of its derivatives are.
Bakuchiol
Bakuchiol
In a 12-week double-blind trial of 44 people, bakuchiol 0.5% and retinol 0.5% reduced wrinkle area and hyperpigmentation to a similar degree, with more irritation on the retinol side. With no vehicle arm, the trial cannot say what the improvement on either side was due to.
Arbutin
Arbutin
The Korean listed amount is 2–5%. In a split-face pilot in 30 people with melasma, alpha-arbutin 5% plus kojic acid 2% did not differ from a prescription triple-combination cream on objective measures, and relapse was worse on the triple-combination side.
Alpha-bisabolol
Bisabolol
The Korean listed amount is 0.5%, the lowest of the nine whitening actives. But we could find no human trial comparing this ingredient on its own against vehicle. What turns up are studies of multi-ingredient formulas.
Medicines used for this concern
Medicines are not listed alongside cosmetic ingredients. Dosage and whether a prescription is needed are settled in consultation.
- Tretinoin Prescription only
- Azelaic acid Over the counter — ask the pharmacist
Clinical procedures related to this concern
Procedures are not listed alongside topical ingredients. They are not something you use at home.
In preparation.