Hyaluronic acid serum or a hydrating moisturizer?

What is the difference?

Hyaluronic acid is a humectant, meaning it attracts and holds water. Moisturizers combine ingredients that attract water, soften skin and reduce water loss. Ingredients that slow evaporation are called occlusives; examples include petrolatum, mineral oil and dimethicone. A moisturizer can contain hyaluronic acid too, so these are not two rival departments fighting over your face. Despite its name, hyaluronic acid moisturizes rather than exfoliates.234

Which should you choose?

• For dry or flaky skin, choose a cream or ointment first. These preserve more water than a lotion.
• For oily skin that needs moisture, consider a light gel instead of a rich cream. Heavy occlusive products can aggravate acne.
• For combination skin, moisturize the dry areas rather than automatically coating the oily areas.
• For extra hydration, use serum beneath moisturizer. If your moisturizer already contains hyaluronic acid, a separate serum is optional.
• For colder, drier weather, switch to a richer moisturizer if a light lotion is no longer enough.

Check the whole formula, not just the ingredient on the front. Useful moisturizer ingredients include glycerin, ceramides and hyaluronic acid, with petrolatum or mineral oil helping retain moisture.14

How do you use them together?

1. 1Cleanse, then leave your skin damp rather than completely dry.
2. 2Apply hyaluronic acid serum, following the product's directions for the amount. You can use it in the morning and evening.
3. 3Immediately follow with moisturizer containing an occlusive ingredient. Smooth the moisturizer gently over skin rather than rubbing it in.
4. 4In the morning, apply sunscreen over moisturizer. Choose broad spectrum, water resistant protection with SPF 30 or higher.

If you are using moisturizer alone, apply it straight after washing. Slightly dry skin can need only a light moisturizer at night; more severe dryness needs more frequent application. Choose a product you are comfortable using at least twice daily if your skin is excessively dry, and reapply when skin feels dry or tight. A cream during the day and a richer ointment at night is another option.135

What should you expect?

Hyaluronic acid can improve dryness and mildly soften the appearance of fine lines within about one to two weeks. That is a hydration effect, not a time machine with a dropper. Moisturizers also help reduce dryness and support the skin barrier, but they need regular application to maintain their benefits.23

What if your skin is sensitive or you use prescriptions?

For dry or sensitive skin, avoid fragrance and do not assume that natural ingredients are less likely to cause allergies. Stop using a moisturizer that makes your skin itchy or sore. Persistent burning, stinging, facial rashes or inflamed follicles warrant advice from a pharmacist or clinician. See a dermatologist if dryness does not improve or becomes painful, cracked or bleeding.156

If you use a prescribed topical steroid, leave at least 30 minutes between the steroid and your emollient moisturizer. Ask your clinician which to apply first; layering them immediately can dilute treatment or spread it to skin that does not need it.56