What Is Hyaluronic Acid?
Hyaluronic acid (HA) is a substance your body already produces naturally — it's found throughout your skin, joints, and connective tissue. Its job is to attract and hold onto water; it's often described as being able to hold up to 1,000 times its weight in water. The catch is that your skin's natural HA levels gradually decline as you age, which is part of why skin can feel less plump and more prone to fine lines over time.
What It Does for Your Skin
When applied topically, hyaluronic acid draws moisture to the skin's surface, which can:
- Improve hydration and plumpness
- Temporarily smooth the look of fine, dehydration-related lines
- Support a healthier-looking skin barrier
- Work for virtually every skin type, including oily and acne-prone skin, since it's lightweight and non-comedogenic
Different Molecular Weights, Different Jobs
Not all hyaluronic acid is the same size. Larger HA molecules tend to sit on the surface of the skin, providing an immediate plumping effect, while smaller molecules can penetrate more deeply for longer-term hydration support. Many serums combine multiple molecular weights to cover both bases.
How to Use Hyaluronic Acid Correctly
The most important tip: always follow hyaluronic acid with a moisturizer. HA draws water toward itself — if there's not enough moisture in the air (like in winter, or in air-conditioned rooms), it can actually pull water from your skin rather than to it. Applying it to slightly damp skin and sealing it in with a moisturizer helps it do its job properly.
Who Should Use It
Pretty much everyone. It's gentle enough for sensitive skin, hydrating for dry skin, and won't add shine for oily skin — which is part of why it's such a staple "Treat" step ingredient across skin types.