Radiant Super C | Stabilised Vitamin C Serum | ST.SAJ

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BRIGHT SKIN INCOMING

RADIANT SUPER C
is our high-performance Vitamin C serum designed to brighten, hydrate, target redness and even skin tone.

WORLD FIRST

ST.SAJ Radiant Super C with white serum droplets on grey background.

Man applying ST.SAJ Radiant Super C to his face, holding Radiant Super C

Close-up of serum texture, key ingredients labelled: Vitamin C, Salicylic Acid, Illumiscin™-Glow, Squalane, Glycerin.

Emmylou holding Radiant Super C, two-step guide: massage 2-3 drops onto face neck and décolletage after cleansing and toning, layer with serums and lock in with a moisturiser, don't forget SPF in the day.

Hands holding ST.SAJ Radiant Super C bottles, text: why we love it, brighten & even out skin tone, refine skin texture, deliver deep hydration, calm & reduce redness.

Founder Emmylou in pink sunglasses holding ST.SAJ Radiant Super C, quote: redness dullness uneven tone not on my watch, I created this powerful Vitamin C serum to smooth brighten and bring out your natural glow because everyone deserves healthy radiant skin.

ST.SAJ Radiant Super C with white serum droplets on grey background.

Man applying ST.SAJ Radiant Super C to his face, holding Radiant Super C

Close-up of serum texture, key ingredients labelled: Vitamin C, Salicylic Acid, Illumiscin™-Glow, Squalane, Glycerin.

Emmylou holding Radiant Super C, two-step guide: massage 2-3 drops onto face neck and décolletage after cleansing and toning, layer with serums and lock in with a moisturiser, don't forget SPF in the day.

Hands holding ST.SAJ Radiant Super C bottles, text: why we love it, brighten & even out skin tone, refine skin texture, deliver deep hydration, calm & reduce redness.

Founder Emmylou in pink sunglasses holding ST.SAJ Radiant Super C, quote: redness dullness uneven tone not on my watch, I created this powerful Vitamin C serum to smooth brighten and bring out your natural glow because everyone deserves healthy radiant skin.

RADIANT SUPER C

Potent Stabilised Vitamin C Illumiscin™-Glow Glycerin

$54.95~~$54.95~~ Save 0%

4.8

Rated 4.8 out of 5 stars

59

Stabilised Vitamin C, Illumiscin™-Glow and salicylic acid. Brightens, evens tone and refines texture - for all skin tones.

Hydrating

Brightening

Smoothing

Revitalising

Free Aus Shipping on orders over $150

Stabilised, oil-soluble Vitamin C penetrates deeper without irritation
Illumiscin™-Glow targets uneven tone, calms redness and boosts luminosity
Salicylic acid gently exfoliates to refine texture and smooth skin
Glycerin and squalene lock in moisture for a dewy, hydrated finish
Designed for all skin tones - brightens without altering natural pigment
Use AM and PM - always follow with SPF during the day

A high-performance brightening serum formulated for all skin tones. Stabilised, oil-soluble Vitamin C works beneath the surface to target dark spots, dullness and uneven tone without irritation. Illumiscin™-Glow boosts luminosity and calms redness. Salicylic acid refines texture for a smoother, clearer complexion. Glycerin locks in moisture and supports the skin barrier. Squalene adds a natural dewy finish.

Apply after cleansing and essence, AM and PM. Layer over PEPTIDE POWER ESSENCE and seal with SUPREME SKIN 7. Always use SPF during the day.

50ml / 1.7fl oz

Massage 2–3 drops into face, neck and décolletage after cleansing and essence.
Seal with SUPREME SKIN 7. Always use SPF during the day.

Aqua, Pentylene Glycol, Glycerin, Ascorbyl Tetraisopalmitate, C13-15 Alkane, Ethoxydiglycol, Olive Oil Decyl Esters, Coco-Caprylate/Caprate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Squalene, Hordeum Vulgare Extract, Salicylic Acid, Tocopherol, Xanthan Gum, Sodium Hydroxide, Dehydroacetic Acid, Benzyl Alcohol, Citric Acid.

No artificial colours, parabens, silicones, phthalates, chemical UV filters.

Complete the Routine

ST.SAJ Skin Refining Glaze 6% Mandelic Acid lightweight exfoliating milk product shot

REFINE WITH

$54.95

SKIN REFINING GLAZE

ST.SAJ Glow Kit - Glow Cleanse, Clear Cleanse, Peptide Power Essence, Radiant Super C and Supreme Skin 7 product flat lay

BUILD WITH

$219.00 ~~$274.75~~

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Australian Made

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VEGAN & CRUELTY FREE

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Radiant Transformation

See the Results

Get next level skin brightening, hydration, and glow.

Not just a pretty bottle

This formula combines proven skin-brightening heroes: Vitamin C, Salicylic Acid, and Squalane, with Illumiscin™-Glow, a world-first innovation in radiance tech.

4.8

Rated 4.8 out of 5 stars

Based on 59 reviews

Total 5 star reviews: 51 Total 4 star reviews: 5 Total 3 star reviews: 2 Total 2 star reviews: 1 Total 1 star reviews: 0

95%would recommend this product

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59 reviews

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LJ
Lisa J. M.
Verified Buyer
I recommend this product
Rated 5 out of 5 stars
5 months ago
Radiant super c
Some people create products that truly make a difference and Emmy from ST.SAJ is one of them 💛 My daughter and I have both fallen in love with her skincare range. I’m 60 and she’s 21, and somehow these products work beautifully for both of us!
But what really stands out is Emmy herself so kind, caring, and genuine. She always takes the time to reply, offer advice, and help me find exactly what my skin needs. That level of personal care is rare these days.
Thank you, Emmy, for everything you do your products 5 stars
Was this helpful?
JS
Jane S.
Verified Buyer
I recommend this product
Rated 5 out of 5 stars
9 months ago
Superb
Currently in Africa and it is very dry - I brought 3 products - peptide power essence, super c and the st
Sai moisturiser- my skin has stayed soft and radiant!! Highly recommend
Was this helpful?
JN
Jacinda N.
Verified Buyer
I recommend this product
Rated 5 out of 5 stars
9 months ago
Amazing
The C serum is incredible! I have been using all St.SAJ
Products since hitting the market can not prase these products enough. I am always told my skin looks and feels soft, smooth and amazing 😍😍😍
Was this helpful?
SG
Stephanie G.
Verified Buyer
I recommend this product
Rated 5 out of 5 stars
10 months ago
OBSESSED is an understatement!
Radiant Super C is hands down one of the best Vitamin C serums I’ve ever used. My skin feels brighter, smoother, and more even-toned,. The texture is lightweight, absorbs beautifully, and layers perfectly under makeup or my supreme skin 7 moisturiser . I’ve tried so many Vitamin C products, but this one from St. Saj Skin Care is next level. You can tell it’s made with high-quality ingredients, and the glow it gives is unreal.
If you’re looking for a game-changer in your skincare routine, this is it. St. Saj has me hooked for life
Was this helpful?
BA
Bronwyn A.
Verified Buyer
I recommend this product
Rated 5 out of 5 stars
11 months ago
AMAZING 👌
This product is amazing. I have been using it everyday for 4 weeks now. I have noticed my complexion has evened out and feels nice on the skin. I will be incorporating this into my daily routine with all my other ST.SAJ products.
Was this helpful?

Why You’ll Love It

✔ Brightens dull, uneven skin tone

✔ Calms redness and supports barrier function

✔ Boosts radiance with Illumiscin™-Glow

✔ Refines texture with Salicylic Acid

✔ Plumps and hydrates with Glycerin & Squalane

We recommend using Radiant Super C in the morning, though it can be used at a time that suits your routine. So if you want to use it in the evening, go for it!

Vitamin C is particularly beneficial during the day as it helps brighten the complexion and provides antioxidant support against environmental stressors.

For optimal layering:

Cleanse → Peptide Power Essence → Hyaluronic Smoothing Complex → Radiant Super C → Supreme Skin 7 → SPF

Always finish with SPF in the morning to protect your skin and preserve your results.
Yes, Radiant Super C is housed in a precision dropper bottle for controlled, hygienic application.

The formula uses a stabilised, oil-soluble form of Vitamin C, which is significantly more resistant to oxidation than traditional water-based L-ascorbic acid formulas. This allows it to maintain stability while being dispensed via dropper.

The dropper format also allows you to customise the amount used, ensuring minimal waste and precise layering within your routine.
“2% Stabilised Vitamin C” refers to both the concentration and the formulation stability of the Vitamin C used in Radiant Super C.

The formula contains 2% of a stable, oil-soluble form of Vitamin C (Ascorbyl Tetraisopalmitate). Unlike traditional Vitamin C (L-ascorbic acid), which can oxidise quickly and lose potency, this stabilised form is designed to remain effective for longer while being gentler on the skin.

This means:

The ingredient maintains its strength and performance over time

It is less prone to rapid oxidation

It supports visible brightness and collagen production

It delivers results without the high irritation often associated with acidic Vitamin C formulas

Rather than relying on high percentages for marketing appeal, Radiant Super C prioritises stability, compatibility, and consistent performance for long-term skin health.
Illumiscin™-Glow is described as a world-first innovation because it was developed as a next-generation brightening complex designed to deliver visible radiance while respecting the skin barrier.

Unlike traditional brightening systems that rely heavily on aggressive exfoliation or high-acid concentrations, Illumiscin™-Glow works through a multi-pathway approach, supporting clarity, tone balance, and luminosity without triggering unnecessary irritation.

What makes it special is its ability to:

Enhance visible glow across all skin tones

Support a more even-looking complexion

Work synergistically with stabilised Vitamin C to amplify brightness

Deliver results without compromising barrier integrity

It allows Radiant Super C to achieve refined, balanced luminosity, not just surface-level brightness.
Illumiscin™-Glow is a next-generation brightening complex developed to deliver visible radiance while respecting the skin barrier.

Unlike traditional brightening systems that rely heavily on aggressive exfoliation or high-acid concentrations, Illumiscin™-Glow works through a multi-pathway approach, supporting clarity, tone balance, and luminosity without triggering unnecessary irritation.

What makes it special is its ability to:

Enhance visible glow across all skin tones

Support a more even-looking complexion

Work synergistically with stabilised Vitamin C to amplify brightness

Deliver results without compromising barrier integrity

It allows Radiant Super C to achieve refined, balanced luminosity, not just surface-level brightness.
Radiant Super C is designed to visibly brighten, refine, and support overall skin clarity. It helps to:

Improve the appearance of uneven skin tone

Enhance radiance and luminosity

Support collagen for firmer-looking, more resilient skin

Refine the look of pores

Promote smoother, more even texture

Provide antioxidant protection against daily environmental stressors

With consistent use, skin appears brighter, clearer, and more luminous while maintaining barrier balance.

Yes. All ST.SAJ products are 100% vegan and cruelty-free. We use plant-based ingredients throughout our formulations. We're not tested on animals and don't sell in markets that require animal testing.
If you follow a vegan lifestyle, you can use our entire range with confidence.
Our salicylic acid products are formulated to exfoliate gently while supporting your skin barrier, not strip it.
Here's the difference: Most salicylic acid treatments are acid-heavy formulas designed for aggressive exfoliation. ST.SAJ products prioritise hydration and barrier health alongside exfoliation. Your skin stays nourished, not compromised.

High levels of glycerin and humectants to draw moisture into the skin
Soothing botanicals (like barley extract and madecassoside) to calm
Our salicylic acid concentration is enough to exfoliate, not enough to irritate

Who can use these?

Normal to oily skin: Daily use
Sensitive or dry skin: Start 2-3 times per week, gradually increase as skin adjusts
Very reactive skin: Alternate nights with a gentle moisturiser, or use only 2x weekly

If you experience irritation:
Stop using and let your skin recover. When you resume, use it less frequently. If irritation persists, discontinue.
The goal is healthy, glowing skin, not red, stripped skin. If a product is making you uncomfortable, it's not the right fit.
We proudly offer Free Shipping on all Australian orders over $150.
Shipping on Australian orders under $150 is a flat rate of $10.00. We also offer express shipping for those that need their skincare in a hurry!
Yes, we do. See our shipping rates at checkout if you are one of our amazing friends abroad.
Please check our Returns Policy for information on returns.
If you believe you’ve had an allergic reaction to a ST.SAJ product, please email glow@stsaj.com straight away. Stop using the product for now, but don’t throw it away. If you’ve used less than 20% off the product we can discuss a refund after our team assesses the images of your reaction.
To celebrate ST.SAJ now available in-store at ULTRA Beauty, customers who purchase ST.SAJ products during the promotional period can enter for a chance to have their purchase refunded.

How to enter:
1. Purchase any ST.SAJ product in-store at ULTRA Beauty
2. Post your purchase on Instagram (Story or post) and tag @stsaj.skin
3. Keep your receipt as proof of purchase

Each week for 8 weeks, ST.SAJ will randomly select one winner to receive a refund of their ST.SAJ purchase.

The promotion runs until 8 May 2026.

Important:
• Promotion is run and funded by ST.SAJ only
• ULTRA Beauty is not responsible for or administering this promotion
• Entries must include an original Instagram Story or post featuring the purchased ST.SAJ product and tagging @stsaj.skin
• Instagram accounts must be set to public so entries can be verified
• Receipts must be dated within the promotional period (8 March – 8 May 2026)
• One entry per purchase
• In-store ULTRA Beauty purchases only
• Proof of purchase is required to claim the refund

This promotion is not sponsored, endorsed, administered by, or associated with Instagram.

“Redness, dullness, uneven tone? Not on my watch!”

I wanted a Vitamin C serum that actually worked, sat beautifully under makeup, kept me hydrated and was backed by science.

– Emmylou xx