How to use them
Use them in the same routine at night. Apply Hydroquinone first, then Zinc PCA, moving from thinnest to thickest texture.
- 1CleanseGentle cleanser, pat dry
- 2Hydroquinone2% – 4% (prescription in India), wait about 1 minute
- 3Zinc PCA1%
- 4Moisturiserseal everything in
What Hydroquinone does
The strongest topical depigmenting agent, used for melasma and stubborn dark spots. It blocks melanin production, but it must be used in short, supervised courses: long-term use can cause irritation and, rarely, ochronosis (blue-black darkening).
- Typical strength
- 2% – 4% (prescription in India)
- When
- PM
- Irritation
- Best for
- Normal, Oily And Combination skin
Everything that pairs with Hydroquinone →
What Zinc PCA does
Zinc salts help regulate sebum and have mild anti-inflammatory and antibacterial effects. That is why zinc so often appears next to niacinamide in oil-control serums.
- Typical strength
- 1%
- When
- AM/PM
- Irritation
- Best for
- Oily And Combination skin
Everything that pairs with Zinc PCA →
Frequently asked questions
Can I use Hydroquinone and Zinc PCA together?
Yes, it is safe. There is no known chemical conflict between Hydroquinone and Zinc PCA, and neither makes the other less effective.
Which goes first, Hydroquinone or Zinc PCA?
Apply Hydroquinone first, then Zinc PCA. The general rule is thinnest to thickest texture, and lowest pH first.
Should I use Hydroquinone in the morning or at night?
Hydroquinone: best at night. Use only under a dermatologist's guidance, typically nightly on the dark patches for up to 3 months, then take a break. Strict daily sunscreen is required or results reverse.
Should I use Zinc PCA in the morning or at night?
Zinc PCA: works morning or night. Use once or twice daily. It works best as part of a niacinamide or oil-control serum.
Is Hydroquinone with Zinc PCA safe during pregnancy?
Hydroquinone is generally avoided during pregnancy and breastfeeding. Ask your doctor about safer alternatives such as azelaic acid or bakuchiol.