Helps skin feel hydrated and comfortable
For skin that feels dry, tight or like it needs another layer of moisture.
Korean PDRN serum
Dry, dull or uneven-looking skin? Start with one focused serum.
Signal Serum is a lightweight daily treatment for skin that needs more hydration, fresher-looking radiance and support for a more even-looking tone. UNA’s proprietary formula brings together 200,000 ppm salmon-derived PDRN, 2% niacinamide, targeted peptides and a multi-hydration complex—without adding another complicated routine step.
30 ml / 1.01 fl. oz. · Use 2–3 pumps AM + PM · Made in Korea
What Signal Serum is designed to support
Helps dull-looking skin look fresher
A lightweight daily step for a complexion that looks tired rather than well-rested.
Supports a brighter, more even-looking complexion
For when tone appears less even than usual and you want a considered, consistent routine.
200,000 ppm salmon-derived PDRN · 2% niacinamide · Targeted peptides · Multi-hydration complex
- 200,000 ppm salmon-derived PDRN
- 2% niacinamide
- Made in Korea
- Complete ingredient transparency
What Signal Serum is designed to support
One focused step for the concerns that often show up together.
Dryness can make skin feel uncomfortable. Dullness can make it look tired. Uneven-looking tone can make a routine feel like it needs more products. Signal Serum keeps the approach focused.
When skin feels dry or tight
The multi-hydration complex helps skin feel softer, more hydrated and more comfortable—without several overlapping hydration steps.
When skin looks dull or tired
PDRN, niacinamide and complementary formula support help skin look fresher and more radiant over time.
When tone appears less even
2% niacinamide supports a brighter, more balanced-looking complexion with consistent cosmetic use.
Why Signal Serum
A transparent formula with a clear role in your routine.
Signal Serum contains 200,000 ppm—equivalent to 20%—salmon-derived PDRN in the finished formula, alongside 2% niacinamide, targeted peptides and a multi-hydration complex. The concentration is useful context; the complete formula is what creates the experience.
Why UNA
Skincare should earn its place in your routine.
UNA began after a routine for persistent dryness kept getting bigger without becoming clearer. We believe you should be able to see what a formula contains, understand why it is there and decide whether it belongs in your routine. Less guesswork. More useful information.
Signal Serum
Signal Serum
$39.99
30 ml / 1.01 fl. oz.
A lightweight Korean gel serum with 200,000 ppm salmon-derived PDRN, 2% niacinamide, targeted peptides and a multi-hydration complex. Designed for consistent use, morning and evening.
- Helps skin feel hydrated, soft and more comfortable.
- Helps dull-looking skin look fresher and more radiant.
- Supports a brighter, more even-looking complexion.
Shop by skin concern
Start with what your skin is telling you.
Clear guidance for the concerns customers most often notice—then a relevant, focused next step.
01
Dryness
Learn how a hydration-focused routine can support a softer, more comfortable skin feel.
Explore guide 02Dull-looking skin
A consistent routine and lightweight treatment step can support a fresher, more radiant-looking appearance.
Explore guide 03Uneven-looking tone
Understand what more even-looking tone means in cosmetic skincare and how daily niacinamide can fit in.
Explore guide 04Skin barrier support
Learn how to simplify your routine when skin feels like it needs a gentler approach.
Explore guide 05Sensitive-feeling skin
Patch test, introduce products gradually and keep routine changes easier to assess.
Explore guide 06PDRN skincare explained
Learn what PDRN means, what concentration can tell you and why the complete formula matters.
Explore guideYour 28-day potential
What consistent use can feel like.
For skin that feels dry, looks dull or appears less even, a focused routine can make a meaningful difference. In an UNA-run consumer self-assessment, 200 adults used Signal Serum morning and evening for 28 days and shared how their skin felt and looked.
Hydration improvement
87%
said their skin felt more hydrated
After 28 days of twice-daily use.
Reduced dry feel
88%
said their skin felt less dry
After 28 days of twice-daily use.
More even-looking tone
84%
said their skin looked more even-toned
After 28 days of twice-daily use.
* Consumer self-assessment; agree or strongly agree responses from 200 adults aged 18–65 after 28 days of twice-daily use. Individual results may vary. This was not a clinical study.
Inside Signal Serum
Four defined roles. One transparent formula.
Each ingredient group has a purpose: hydration and comfort, fresher-looking radiance, more even-looking tone and smooth-feeling skin. The formula is designed to make those roles work together in one lightweight step.
200,000 ppm PDRN
Equivalent to 20% salmon-derived PDRN in the finished formula. A clearly disclosed concentration—not an unexplained hero claim.
Learn about PDRN2% Niacinamide
Supports a brighter, more even-looking complexion while fitting a daily routine.
Niacinamide and toneMulti-hydration complex
Sodium hyaluronate, glycerin, betaine and trehalose help skin feel hydrated, soft and comfortable.
Targeted peptides
Palmitoyl Pentapeptide-4, Acetyl Hexapeptide-8 and GHK-Cu complement the formula for smooth, resilient-looking skin.
PDRN and peptidesQuestions before you buy
The practical details, clearly answered.
Everything you need to know before adding a new serum to your routine.
What is PDRN?
PDRN is commonly used as an abbreviation for polydeoxyribonucleotide. In Signal Serum, the salmon-derived material is listed as Sodium DNA. Learn about the formula.
How much should I use?
Apply a small amount after cleansing, then follow with moisturizer. Start with the amount stated on the packaging and adjust only if needed.
Can I layer it with other skincare?
Yes. Keep the routine measured and avoid introducing several unfamiliar products at once.
Is it suitable for sensitive-feeling skin?
Individual tolerance varies. Patch test first, introduce gradually and stop use if persistent discomfort occurs.
Where can I find the full ingredient list?
Review the current full ingredient list on the Signal Serum product page and packaging before use.