Ultra Pure High-Potency 5.0% Niacinamide Serum

Kiehl's Since 1851 Ultra Pure High-Potency 5.0% Niacinamide Serum is a decent serum with an overall score of 6.4/9.8. Positioned in the premium bracket, it takes a straightforward approach to skincare. The formula leads with Niacinamide, Glycerin, Propanediol — ingredients that actively target skin concerns.

It performs well on low irritation risk (9.5). On the flip side, hydration could be stronger and active ingredient concentration is on the lighter side.

Is this right for you?

Great for

• ✓Sensitive skin — low irritation risk with a gentle formulation
• ✓Safety-conscious shoppers — clean formulation with minimal flags
• ✓Ingredient-aware buyers — transparent, well-documented formula

May not suit

• ⚠Very dry skin types looking for heavy-duty moisture
• ⚠Those seeking potent actives — this leans more maintenance than treatment

Key ingredients

• ✶
  Niacinamide

  Works on your skin — #2 in the INCI list

• ✶
  Glycerin

  Draws in moisture — #3 in the INCI list

• ✶
  Propanediol

  Draws in moisture — #4 in the INCI list

• ✶
  Methyl Gluceth-20

  Draws in moisture — #5 in the INCI list

• ✶
  Sodium Hyaluronate

  Draws in moisture — #7 in the INCI list