No.5 Vitamin Concentrated Serum — Reddit Reviews

• Hyperpigmentation

  Strong evidence

  Tranexamic Acid: 12 studies tested it on its own. See all 21 studies→

  On Reddit: Melanin inhibitors like tranexamic acid and niacinamide help this serum fade dark spots for daily use without irritation. 37 mentions

  Both ingredients for hyperpigmentation

  Tranexamic Acid · Strong evidence

  • Most studies found tranexamic acid helped fade dark patches
  • It often faded melasma better than a placebo
  • Used on its own, it often worked about as well as hydroquinone
  • Used with laser or microneedling, it often helped more than those treatments alone
  • Some studies found no clear extra benefit in certain forms or comparisons

  Niacinamide · Some evidence

  5 studies tested it on its own. See all 24 studies→

  • All of these studies found niacinamide helped fade dark spots or patches
  • Niacinamide 5% faded dark spots more than a placebo in studies of sun-damaged skin and dark patches
  • Used with salicylic acid peels, niacinamide improved dark patches more than peels alone
  • A niacinamide mix faded dark spots better than niacinamide alone in one study
  • One study found the fading effect reversed after niacinamide was stopped

• Acne

  Some evidence

  Niacinamide: 6 studies tested it on its own. See all 17 studies→

  What the studies found

  • Most studies found niacinamide helped acne
  • It often cleared acne about as well as clindamycin
  • Some studies found fewer red, sore spots with 4% niacinamide
  • Some evidence was uncertain, and some studies found no clear difference

Research context, not treatment advice. Studies are about the ingredient, not necessarily this exact product.