Japanese Vitamin C Serum and the Vitamin C / HA Layering Question

If you use a vitamin C serum, you have probably wondered whether to apply vitamin C or hyaluronic acid first. DAMDAM's Citrus Glow settles the question by formulating both in one serum, so you apply them together in a single step. It pairs stabilized vitamin C with hyaluronic acid, brightening and hydrating at once.

Should I apply vitamin C or hyaluronic acid serum first?

The usual advice is to apply the thinner, more active product first, which normally means vitamin C before a hyaluronic acid layer. It is a fussy rule, and it is easy to get wrong.

With Citrus Glow the order question does not arise. Vitamin C and hyaluronic acid are formulated together in one serum, so there is no "first" and "second": you apply them in a single step. That is the simplest honest answer to the layering question, one product instead of two decisions.

What is a Japanese vitamin C serum?

"Japanese vitamin C serum" is a product-type search rather than a single defined formula. What tends to characterise the Japanese approach is stabilized vitamin C in a gentle, well-textured base, often paired with hydration so the result is comfortable rather than stripping.

Citrus Glow is DAMDAM's version. It uses two stabilized vitamin C derivatives together with hyaluronic acid, held in DAMDAM's Japan-developed 3PE (triphasic emulsion) technology, which is how it keeps two kinds of vitamin C and hyaluronic acid stable in the same serum.

Can you use vitamin C and hyaluronic acid together?

Yes. Vitamin C and hyaluronic acid do different jobs and work well side by side: vitamin C targets radiance and dullness, hyaluronic acid draws in and holds water. They are a common pairing precisely because they complement each other.

Citrus Glow makes that pairing the point: rather than layering two serums and worrying about order, you get both actives in one step.

What is amanatsu, and is it the vitamin C?

Amanatsu is a Japanese citrus, the sweet summer orange (natsumikan). In Citrus Glow it appears as amanatsu peel oil, a citrus botanical note in the formula. It is worth being precise: the serum's vitamin C comes from stabilized vitamin C derivatives, not from the amanatsu. The amanatsu is a Japanese citrus accent, not the active source of vitamin C.

About Citrus Glow

Citrus Glow (Vitamin C + Hyaluronic Serum) pairs two stabilized vitamin C derivatives with hyaluronic acid to brighten and hydrate in a single step, using DAMDAM's 3PE technology. It carries amanatsu (Japanese summer orange) peel oil as a citrus botanical, and was named in Refinery29's best beauty products of Fall 2023.

Because vitamin C and hyaluronic acid are already together, Citrus Glow is the DAMDAM answer to both "which Japanese vitamin C serum" and "which do I apply first": one serum, one step. In the US, DAMDAM is available at Sephora, where it carries the Clean + Planet Aware seal, and on damdamtokyo.com; in Japan, you can also find DAMDAM at its Kyoto flagship and stockists including Isetan and Ron Herman.