Niacinamide or hyaluronic acid: which is better?

How they differ

Hyaluronic acid binds water to collagen and helps skin look plumper. The word acid is doing an unhelpful amount of work here: hyaluronic acid is a sugar molecule, not an exfoliating hydroxy acid.1

Niacinamide is vitamin B3. It can support the skin barrier by reducing water loss, and topical studies report improvements in fine lines, pigmentation, texture and redness. Reviews also discuss its potential effects on oxidative stress and inflammation.34

Hyaluronic acid products are not all the same: their molecular weights and formulas affect how they hydrate the skin. Lower molecular weights reach deeper layers of the skin's surface, while higher ones provide surface hydration, so check the product rather than judging by the ingredient name alone.2

How long do they take to work?

The timing depends on the formula and the result you want. The Ordinary describes its Hyaluronic Acid 2% + B5 with Ceramides as providing immediate, all day hydration. In one 12 week study, 5% topical niacinamide improved fine lines, pigmentation, texture and redness. A separate study found reduced facial oil after 4 to 6 weeks of using a 2% niacinamide moisturizer. Four to six weeks is a long appointment for a little bottle, but that is the time frame for this oil related result.23

How should I use them?

Directions vary by formula. The Ordinary directs users of its Hyaluronic Acid 2% + B5 with Ceramides to apply a few drops after cleansing, morning and evening, on wet or dry skin. Let that serum dry completely before layering other products, then follow with a moisturizer. For other products, follow their own directions.2

If you are new to The Ordinary's formulas, introduce them gradually and patch test first. The brand lists its hyaluronic acid and niacinamide formulas as suitable for all skin types, including sensitive skin, while noting that individuals can respond differently.2

Can I use niacinamide and hyaluronic acid together?

Yes. Hyaluronic acid adds hydration, while niacinamide supports the barrier and helps with excess oil, so both can fit the same routine; the bottles do not need to negotiate custody of your face.2

Which goes first, niacinamide or hyaluronic acid?

For The Ordinary's water based serums, the order can follow your main concern: apply hyaluronic acid first if dryness is the priority, or niacinamide first if you are targeting pore visibility. If you use its Hyaluronic Acid 2% + B5 with Ceramides, let it dry before layering another product.2

Is niacinamide or hyaluronic acid better for dry skin?

Hyaluronic acid is the more direct choice when dryness is the main concern because it binds water and supports a plumper look. Niacinamide can also suit dry skin because it supports the barrier and helps reduce water loss. If dryness comes with excess oil or uneven tone, using both is a reasonable way to address those different concerns.123