Hyaluronic acid is one of the most widely used and studied hydrating ingredients in skincare. This comprehensive guide covers everything you need to know — from how it works to how to use it correctly for maximum results.
What is Hyaluronic Acid?
Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan found throughout the body. In skin, it holds water — up to 1,000 times its own weight — maintaining hydration and plumpness. As we age, natural HA levels decline, contributing to dryness and fine lines.
How Hyaluronic Acid Hydrates Skin
HA works as a humectant — it draws moisture from the environment and deeper skin layers into the surface. Different molecular weights penetrate to different depths: low molecular weight HA reaches deeper layers, while high molecular weight HA stays on the surface forming a hydrating film.
How to Use Hyaluronic Acid Correctly
- Apply to damp skin for best results — HA needs moisture to bind to
- Use 1-2% concentration serums for visible hydration benefits
- Follow immediately with a moisturizer to seal in the hydration
- Use morning and evening — HA is suitable for all skin types
- Always finish morning routine with SPF
Who Benefits Most from Hyaluronic Acid?
HA benefits virtually all skin types but is especially valuable for dehydrated, dry, and mature skin. It is non-irritating and safe for sensitive skin. Those with oily skin can use lightweight HA serums without adding excess oil.
Radiant Skin Project is a 501(c)(3) nonprofit providing free skincare science education. Explore more in our free ingredient guides.
