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.

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122 reviews

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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 days 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.

10 days ago
Certified Buyer
  • Skin Type Combination
  • Skin Tone Medium
  • Facial Features Chinita
  • Age 20

can't stop touching my face!!! so smooth!

Ever since, i've always had whiteheads around my nose and milia on my forehead and eyes, and my skin texture has always been a bit rough because of it. But when i used this, WOW!!! I noticed such a huge improvement on my skin texture after my 2nd use! Now i have to keep myself from touching ny face because of how unbelievably smooth and soft it is. Amazing! However i am giving it 4 stars because after my first use, i started having small bumps on ny forehead and my boss commented that my face got darker 😭 good product still though

12 days ago
Top Reviewer
  • Skin Type Oily
  • Skin Tone Fair
  • Facial Features Morena
  • Age 21

Time will tell

I'm in the verge of exploring products that will help me lighten my acne scars, so this came to my mind. It's a good product for skin because of its ingredients which has vitamin C. but in lighting up my spots i really did not see any effect... UNTIL i've used it for months. its not fast but its effective. time will tell <3

12 days ago
Certified Buyer
  • Skin Type Sensitive
  • Skin Tone Medium
  • Facial Features Morena
  • Age 23

Not for me.

At first, i am loving this product. It really feels good on the skin when you store it in the fridge. And at first I saw its effect. Its a little bit tacky but it will dries up in a couple of minutes. But as time goes by, i think the effect of the product is not that good as before. Maybe because there will be a change of color, and with that, its effect also change and fades. But im not saying that this is not good. Its just, that it is not for me. What works for me might not work for you, and what works for you might not work for me.

19 days ago
Certified Buyer
  • Skin Type Oily
  • Skin Tone Medium
  • Age 26

Worth the Try

I was searching for a great face serum last March and I have read good reviews about this product. Now that I have finished the bottle, I can definitely say that this is a good product. There is sometimes tingling feeling on the skin. I think on what I have read on other comments, the vitamin c in this serum may react to some ingredients in our skin care because of that, I just use this during the night and wait for 20 mins to make sure that it has been conpletely absorbed by my skin. Will definitely repurchase this :)

about 1 month ago

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