Vitamin C

Why Does It Always Turn Orange?!

Skincare Ingredient Decoder Series: Vitamin C, explained by someone who has watched way too many serums die on the shelf.

You know that moment when you finally buy a “fancy” vitamin C serum, put it lovingly on your shelf, feel like a grown woman with a proper skincare routine… and then two weeks later it looks like iced tea?

That was me. Standing there, holding a once-milky serum that had turned a suspicious shade of orange-brown, thinking:

• “Is it dead?”
• “Can I still put this on my face?”
• “Did I just donate 40€ to the skincare gods for nothing?”

Vitamin C is one of those ingredients everybody says you need if you’re “serious” about skincare: brightens, fades spots, protects from free radicals (whatever those are before coffee). Oh and it might also sting, oxidize or do absolutely nothing if you pick the wrong one.

So in this chapter of my Skincare Ingredient Decoder Series, I’m going to talk you through vitamin C the way I wish someone had done for me: no fear, no gatekeeping, just one confused woman to another.

Let’s start with what this stuff actually is.

What Is Vitamin C in Skincare (and Why Is It So Dramatic)?

In science language, the “classic” vitamin C in skincare is called L-ascorbic acid.
In my language: it’s a powerful antioxidant ingredient that loves to help your skin but also loves to have a meltdown in the bottle.

What it’s supposed to do:

• Help fight free radical damage from UV, pollution and life in general
• Brighten dull skin so you look less “I work too much” and more “I drink water and sleep”
• Support collagen, which is the bouncy stuff in your skin that slowly packs its bags over time

But here’s the problem: vitamin C (especially L-ascorbic acid) is a full-time diva.

It:

• hates air
• hates light
• hates heat
• turns yellow, orange, or brown when it oxidizes
• and sometimes stings like it’s punishing you for having pores

So if you’ve ever thought, “Maybe vitamin C just doesn’t work for me, it might not be you. It might be your formula, your percentage or your poor serum just… dying.

What Vitamin C Can Actually Do for Your Skin

Let’s skip the glow-filter marketing and talk about what vitamin C can realistically do when it’s well-formulated and you use it consistently.

1. Make Your Skin Look More “Awake”

If your face often says “I’m tired” even when you’re not, vitamin C can help with that slightly gray, dull, “my skin is just… meh” vibe.

With regular use, vitamin C can:

• Make skin look brighter and more alive
• Give a subtle radiance, like you slept one extra hour (even if you didn’t)
• Help your skin look a little more fresh and even, instead of flat and tired

It’s not going to give you a built-in ring light, but it can gently upgrade you from “washed out” to “oh okayyyy, she looks well-rested today.”

2. Help Fade Dark Spots and Old Pimples’ Revenge

If you have little brown spots from old pimples, sun spots or that patchy uneven tone that only shows up when you turn your head a certain way in bad bathroom lighting (rude)- vitamin C can help.

It:

• Interferes with melanin production (the pigment that makes dark spots)
• Helps post-acne marks fade faster
• Can make your overall tone more even over time

But: this is a slow burn not a fast filter. You’re looking at weeks to months, not days and it works so much better with sunscreen because what’s the point of fading spots if the sun is busy making new ones?

3. Support Collagen and Early Fine Lines

Vitamin C doesn’t erase wrinkles like filler but it plays a supporting role in:

• collagen production
• keeping your skin a little firmer and springier
• softening the appearance of very early fine lines and crepey texture

If I think of retinol as the “night shift supervisor” for skin renewal, vitamin C is the “day shift assistant manager” making sure the environment isn’t constantly attacking your collagen.

4. Act as an Antioxidant Shield Under Your SPF

The part you don’t see but future-you will appreciate: vitamin C is an antioxidant.

That means it helps neutralize:

• free radical damage from UV
• pollution
• smoking (including being around other people’s)
• general environmental stress

In practical terms, it:

• Adds an extra layer of protection under your sunscreen
• Helps slow down some of the stuff that leads to visible aging
• Is like giving your skin a little security detail during the day

Vitamin C is not sunscreen. But together? Vitamin C + SPF is a very cute power couple.

Is Vitamin C for You? (And When It’s Maybe Not the Vibe)

You absolutely do not have to use vitamin C to have nice skin. But it might be worth it if certain things are bugging you.

Vitamin C Is Probably a Good Idea If…

You look in the mirror and think things like:

• “My skin just looks… dull.”
• “These acne marks are taking forever to fade.”
• “I want something in the morning that actually does something, not just moisturize.”

Vitamin C might be your girl if:

• You want brighter, more even tone
• You want extra protection under your SPF
• You’re into the idea of long-term anti-aging supportand not instant miracles

You Might Need to Be Careful If…

• Your skin is very sensitive, easily red or reactive
• A lot of serums sting especially ones with acids
• You already use many strong actives: AHAs, BHAs, retinoids, peels, etc.
• You have rosacea that flares when you use acidic products

If that’s you, it doesn’t mean you’re banned from the vitamin C club. It means:

• Start with gentler forms (derivatives)
• Use lower percentages
• Introduce it slowly instead of splashing 20% L-ascorbic on your face like you’re marinating chicken

Types of Vitamin C: The Overwhelming Part (Don’t Worry, I’ll Translate)

Let’s talk about the different forms you’ll see on labels. Each has a personality just like exes.

1. L-Ascorbic Acid- The Strong, Drama-Prone Classic

This is the form of vitamin C with the most research behind it.

Pros:

• Very effective for brightening and antioxidant protection
• Can help with pigmentation and overall radiance
• Often in 10–20% ranges for real results

Cons:

• Can be irritating especially at higher percentages
• Needs a low pH (more acidic), which sensitive skin sometimes hates
• Oxidizes easily especially in clear dropper bottles
• Often sticky or tacky (not always but often enough)

L-ascorbic acid is like that intense friend: amazing when things are good but can be a lot to handle.

Best for:

• Normal, combo or oily skin that handles actives fairly well
• People who want the most “classic” vitamin C benefits and are okay with a bit of sting

2. Vitamin C Derivatives — The Gentler, More Chill Cousins

These are modified forms of vitamin C that are usually more stable, often less irritating, and sometimes a bit less punchy than L-ascorbic acid.

You might see:

• Ascorbyl glucoside
• Magnesium ascorbyl phosphate
• Sodium ascorbyl phosphate
• 3-O-ethyl ascorbic acid
• Ascorbyl tetraisopalmitate (oil-soluble)

Pros:

• Often gentler on sensitive skin
• Less dramatic with oxidation
• Can come in more hydrating or creamy formulas

Cons:

• Sometimes slower or milder in visible results
• Research varies between different derivatives (some have more data than others)

Best for:

• Sensitive or easily-irritated skin
• Beginners who don’t want their morning serum to feel like a punishment
• People who want some brightening, without going hardcore

How Strong Should Your Vitamin C Be?

Here’s how I think about it:

• Very sensitive / nervous beginner: 5–10% vitamin C or a gentle derivative
• Normal / combo / not too sensitive: 10–15% L-ascorbic acid is a good sweet spot
• Experienced / not sensitive / chaos-tolerant: up to 20% L-ascorbic acid, if your skin has proven it can handle it

More than 20% isn’t “more effective” for most faces. It’s just more likely to make your skin sit you down for a difficult conversation.

How (and When) to Use Vitamin C Without Hating It

Vitamin C loves the morning. That’s when it does its best work.

My Basic Vitamin C Morning Routine Template

This is the minimal, realistic version:

• Cleanser (or just lukewarm water if you’re dry and not dirty)
• Vitamin C serum
• Moisturizer
• Sunscreen (SPF 30+)

That’s it. No need to build a 12-step ceremony unless that genuinely brings you joy.

How Often to Start

What I do and recommend for beginners:

• Start with vitamin C 3–4 mornings per week (e.g., Monday, Wednesday, Friday, Sunday)
• Use it for 2–3 weeks and watch how your skin behaves
• If your skin is chill, move to daily use

If you’re already using retinol at night, this pairing can work beautifully:
Morning: Vitamin C + SPF
Night: Retinol on some nights, hydration and barrier care on others

What It Should Feel Like

You might feel:

• A tiny bit of tingling that disappears in a minute or two
• A slight warmth just after applying

That can be normal, especially with L-ascorbic acid.

Not okay:

• Burning that continues
• Intense itching
• Skin turning red and staying angry

If that happens, your skin is saying, “No thank you.” You can use it less often, try a lower percentage or switch to a gentler derivative formula.

How to Stop Your Vitamin C from Dying on the Shelf

If your vitamin C keeps oxidizing faster than your enthusiasm, here’s what I pay attention to now:

1. Packaging

Red flags:

• Completely clear glass bottles sitting in direct light
• Dropper bottles that you open constantly and wave in the air like a wine tasting

Green flags:

• Opaque or tinted bottles
• Airless pumps (the dream)
• Brands that actually mention stability in their description

2. Storage

Things I try to do (when I’m not chaotic):

• Keep vitamin C away from sunlight and heat- not on a sunlit windowsill
• Close the bottle tightly
• Don’t leave it open while I’m answering messages or scrolling

Some people refrigerate theirs. I personally just keep it in a drawer or cabinet, somewhere cool-ish and not under a lamp or next to a radiator.

3. Color and Smell Check

Signs it might be time to break up:

• A serum that started clear or pale and is now deep yellow/orange/brown
• A weird metallic or off smell that wasn’t there before
• Your skin suddenly reacts to a bottle that used to feel fine

A very slightly pale-yellow vitamin C isn’t automatically trash. But the darker and browner it gets, the more oxidized it is and the less helpful (and more irritating) it can be.

I know it’s painful when it was expensive. But an angry oxidized vitamin C serum is like old orange juice: just because it’s still liquid doesn’t mean you should drink it.

What Not to Do with Vitamin C (From My Personal “Never Again” List)

1. Using 20% L-Ascorbic Acid on a Sensitive, Unprepared Face

If your skin already hates strong acids or gets red easily, starting with a high-strength, low-pH vitamin C is… bold.

If that was you (also me), it’s not a failure to downgrade. It’s a survival strategy.

2. Mixing Every Strong Active in One Routine “For Results”

Vitamin C + strong AHA + strong BHA + retinol + a prayer is not a routine. That’s a threat.

If I’m using vitamin C in the morning here’s what I don’t stack with it in the same routine (especially if I’m being good to my barrier):

• Very strong AHAs
• Strong exfoliating toners
• Extra intense “peels”

Instead, I let vitamin C have the morning and save retinoids and stronger exfoliants for select nights.

3. Expecting It to Replace Sunscreen

Vitamin C is not permission to be reckless in the sun.

It:

• does not block UV
• does not mean you can skip SPF
• does not mean you can “stay out longer because I’m wearing antioxidants”

Vitamin C is the supporting cast. Sunscreen is still the main character.

4. Forcing Yourself to Finish an Oxidized Bottle Because It Was Expensive

Listen, I have finished things I should’ve thrown away. I have been that person.

But if it’s dark orange/brown, smells weird or your skin suddenly hates it, it’s no longer a vitamin C serum. It’s an irritant with nostalgia.

Vitamin C Myths I’m Tired of Hearing

“If it doesn’t sting, it’s not working.”

No. Stinging tells you more about your skin barrier, the formula’s pH and whether your face is already irritated than how “effective” it is.

You don’t earn skincare points for suffering.

“Only L-Ascorbic Acid Works. Everything Else Is Useless.”

L-ascorbic acid has the most studies behind it, yes! But that doesn’t mean derivatives are trash.

If your skin hates classic vitamin C or you just want something gentler, using a well-formulated derivative is 100% valid. A product you actually use consistently will always outperform the one that lives in your drawer because you’re scared of it.

“Higher Percentage = Better Results”

Past a certain point (around 10–20% for L-ascorbic), more isn’t always more. More can just be more irritation, more redness and more “why is my skin mad” texts to your group chat.

“Vitamin C Always Pills or Is Sticky”

Some are. Plenty aren’t. Texture depends on the base (watery, gel, lotion, oil), how you layer it and how much you use.

If one serum pills, it doesn’t mean vitamin C as a whole is trash. It might just not play well with your moisturizer or SPF.

How to Read a Vitamin C Label Without Crying

On the back, you might see:

• L-ascorbic acid — the classic, most proven form
• Ascorbyl glucoside
• Magnesium ascorbyl phosphate
• Sodium ascorbyl phosphate
• 3-O-ethyl ascorbic acid
• Ascorbyl tetraisopalmitate (or other “ascorbyl + long word” combos)

Things that make me feel better about a formula:

• Opaque or tinted packaging
• Already looks clear to very pale when new
• Sometimes paired with vitamin E and ferulic acid (common antioxidant trio)

If a product screams “VITAMIN C!” in huge letters on the front but I can’t find any actual vitamin C ingredient in the INCI list on the back… I mentally unsubscribe.

Vitamin C Cheat Sheet (For When Your Brain Is Full)

Question	Quick Answer
What does it do?	Brightens, helps fade dark spots, supports collagen, adds antioxidant protection.
When do I use it?	Morning, under sunscreen.
Good starting strength?	5–10% for sensitive; 10–15% L-ascorbic for not-so-sensitive.
How often?	Start 3–4x per week, then build to daily if your skin is happy.
Plays well with?	Sunscreen, niacinamide, hydrating serums/creams.
Be cautious if…	You have very sensitive, reactive, or already irritated skin.
Big red flags?	Deep orange/brown color, weird smell, sudden irritation.
Mindset?	Long-term support ingredient. Think months, not days.

This is the Vitamin C chapter of my Skincare Ingredient Decoder Series.

Missed the first chapter of the series?

← Back to the Retinol Guide

Hyaluronic Acid → Hydrated, Not Greasy