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My Signature C Source

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CLAIM TO FAME: A best-selling serum that contains 40 times more Vitamin C than orange, 120 times more than strawberries, and 200 times more than mandarins

FAST FACTS: Packed with potent amounts of vitamins for beautiful, healthy skin; contains 6,000mg of 100% pure Vitamin C; helps prevent premature skin-aging; protects, softens and moisturizes skin; has 20% L-Ascorbic acid concentrate for gentle peeling and exfoliation

PERFECT FOR: Clearing out imperfections and dark spots

Note: Given the nature of Vitamin C, the serum may crystallize around the opening of the bottle. This does not alter the quality of the product.

Feb 29, 2016
”19, M, Oily Skin. This product is incredible. I have a lot of post acne scarring, general redness, and uneven skin; introducing C20 into my routine changed my face in a matter of weeks. I cant even really tell what it did- what I know is that my skin’s redness is much more subtle and that many of my imperfections have been smoothed. I put this on after cleansing and toning, and while I don’t know any of the science behind it, I feel like I can say that it helps all the next products i use become more effective. Make sure you wait 20 minutes after using it for best results.”
– Raynor14 (from amazon.com)

A cost-effective way to change your skin
Nov 4, 2015
”I started using this serum about a month ago and I have already seen big changes in my skin. I am in my mid-30s and suffer from Melasma and fine lines. After a month of use my skin texture is so much smoother and the Melasma that is above my upper lip has faded a lot.”
– MT (from amazon.com)
Holy Grail
Sept 8, 2015
”I have combination/oily skin. After about using thus product for a month, I saw that my acne has improved, my pores were reduced a little in size, and my skin complexion became more even. I would buy this again and I definitely recommend this product!”
– Marla Baconawa (from amazon.com)

WHAT YOU GET: (1) bottle My Signature C Source
Water, Ascorbic Acid, Alcohol, Sodium Lactate, Butylene Glycol, Glucose, PEG-60 Hydrogenated Castor Oil, 1,2-Hexanediol, Phenoxyethanol, Sodium Hyaluronate, Bis-PEG-18 Methyl Ether Dimethyl Silane, Xanthan Gum, Diethoxyethyl Succinate, Ammonium Acryloyldimethyltaurate/VP Copolymer, Carthamus Tinctorius (Safflower) Flower Extract, Citrus Aurantium Dulcis (Orange) Peel Oil, Glycerin, Zinc PCA, Panthenol, Niacinamide, t-Butyl Alcohol, Camellia Sinensis Leaf Extract, Beta-Glucan, Tocopheryl Acetate, Lecithin, Caprylic/Capric Triglyceride, Ubiquinone, Diisopropyl Adipate

STEP 1: Apply after cleansing and toning. Use 2~3 drops and smooth in gently all over face (especially over the aged areas such as pigmented or wrinkled lesions).
STEP 2: Initially, a slight tingling sensation may be experienced (a passing phenomenon).
STEP 3: Mix with several drops of toner to make your skin refreshed without feeling gooey.
STEP 4: After applying vitamin source C20, apply moisturizer to increase efficacy.

If you desire more hydration, use this product with the C20 Vitamin Sleep 9 to 5 Crema Sleeping Cream. After applying the C20 Vitamin serum, apply the sleeping cream over this layer. This combination will amplify the effects of Vitamin C.

Caution: When you use this product, please avoid using any products that contain high levels of AHA, BHA (include Betain Salicylate), Retinal, Vitamin C (Ascorbic Acid). Because of the hot weather, some vitamin serum can be leaked. But this is a natural phenomenon that can only happen to pure vitamins. When this happens, wipe leaked liquid, and keep it in fridge. Then you may use it without any problems.


Formerly known as C20, Tiam has one simple mission: “Helping you to be more beautiful.” Tiam believes that as long as you wish to be beautiful, you will be beautiful! This South Korean brand explores, all over the world, to find the best beauty products and introduce them to inspiring beauty explorers.

View all from this brand
Sit tight, beautiful things
are worth the wait!

126 reviews

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4.2 out of 5
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Certified Buyer
  • Skin Type Sensitive
  • Skin Tone Fair
  • Facial Features Chinita
  • Age 22

The Worst Skincare Purchase EVER

I had high hopes about vitamin C serums to address the dullness of my skin and all the hyperpigmentation. I tried this out in hopes to finally get rid of my redness and acbe scars - but I was wrong. The first time I tried it, my face was so itchy, so red, and even in pain (I'm not even kidding). I stil gave it a chance because the dumb me was thinking maybe my skin is just adjusting and whatnot. BUT I WAS WRONG. The next morning, my face was so red and full of bumps! There's no way I will put this serum on my face again. This is just the worst. P.S. This is just my personal experience so it doesn't mean the same thing will happen to you if you try this out. Just purchase to your own discretion. - Aki, male, 22

2 months ago
Top Reviewer
Certified Buyer
  • Skin Type Dry
  • Skin Tone Fair
  • Age 21

Multi-purpose product!

It's a great product especially for reducing hyperpigmentation, acne scars and blemishes. It also helps improve texture and diminish fine lines. I sometimes dilute it with water and use it as replacement for acv whenever i do a clay mask. The only downside is that it is very unstable and expires easily. But it's still worth every cent!!

2 months ago
Certified Buyer
  • Age 27

Good Product

I am not really sure if this product does the changes in my skin but it is one of the new products that I used. I noticed that my skin becomes smooth ann clearer after using the product. The effect is not instant and you need to wait months to see visible results.

3 months ago
Certified Buyer
  • Skin Type Oily
  • Skin Tone Medium
  • Facial Features Morena
  • Age 27

Not for me and my pillow sheets

I was really excited when I finally got my hands on this one so I immediately tried it on my face that night. 3 drops were enough but you've got to spread it on immediately because it dries pretty fast. I used it every night for a month. Unfortunately, it did not work for me. My acne scars didn't fade, though I did not breakout. It did stain my pillow sheets, too. I guess it just wasn't for me.

3 months ago
Certified Buyer
  • Skin Type Oily
  • Skin Tone Medium
  • Facial Features Morena
  • Age 25

Real brightening effect

When I learned about serums and essences Ive searched for products with good reviews and that’s when I discovered my signature c serum. Before I used this product I was suffering from an “after travel” breakout and the products I used seems like no effects at all that’s why I bought this serum together with its sleeping cream. After a month of using this , people started complementing my skin and even asked what I am using. This product really brightened my face as well as my acne scars. The downside of this product is just its kinda sticky when applied(tolerable anyway). I will definitely repurchase this product but I want to try some other serums first for comparison.

3 months ago
Top Reviewer
  • Skin Type Oily
  • Skin Tone Medium
  • Facial Features Morena
  • Age 26

No results yet

Bought this for my mom for her melasma, no results yet. She uses this every night. And no bad reactions, oily face din sya. Tried it myself once, it's kinda oily after applying. Never applied it after that one time, 'cause I researched that it's not good to be in a skincare routine with products that has AHA&BHA. Hopefully, gumana.

3 months ago

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