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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111 reviews

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  • Skin Type Combination
  • Skin Tone Medium
  • Facial Features Morena
  • Age 24

Perfect for ANNOYING pimples and scars!

This product is perfect for treating annoying pimples and scars. It does smell nice and the texture is not that watery. Sometimes it stings (esp if there's open wounds due to pimples). I love using this before going to bed because it keeps me fresh the next morning. Now I am almost make-up free!!! Just make sure you secure this in the fridge and wear sunscreen!!!

about 2 months ago
  • Age 21

It was great!

Love this product because it really worked with lightening my acne scars! It also prevented me from getting really large pimples. Just be careful to use it with sunblock if ever you're going out (I only used it at night tho). Also it's a bit hard to maintain because it's pure vitamin C, so make sure to put it in the ref and close it tight so that it won't oxidize right away. Overall good product I just wish it could last longer!

about 2 months ago
Certified Buyer
  • Skin Type Sensitive
  • Skin Tone Fair
  • Facial Features Mestiza
  • Age 20

MY HG! Life saver!

Definitely on my HG list! I just bought this at first for my dark spot near my nose caused by a cystic acne. At first, I just apply it on the dark spot but started putting it on my cheeks as well and within a week of constant use, my skin was glowing! The dark spot is clearing fast as well! VERY WORTH IT!

about 2 months ago
Top Reviewer
  • Skin Type Oily
  • Skin Tone Fair
  • Facial Features Mestiza
  • Age 21

Lightens scars but..

I got this one because It's Skin VC is out of stock. I had terrible hormonal acne around my jaw that I suffered for almost two months. It left me deep red hyperpigmentation. I opt for this one because of the high amount of vitamin c in the product. It did lighten my deep red scars, but it gives me this burning sensation and makes my face feel thin and vulnerable. That is why I only use this once or twice a week, depending on the state of my skin. This will last me a while because I dont put that much whenever I apply, just 2-3 drops will do. Will not be repurchasing though, It's Skin VC is better in my experience.

2 months ago
Certified Buyer
  • Skin Type Oily
  • Skin Tone Fair
  • Age 33

Might work better for healed skin

Bought this last Aug 2017 when I broke out so bad (as in multiple cystic pimples) because of a toner which contained essential oils, so my aim was to fade post pimple marks and discourage new pimples from popping up as vitamin c supposedly encourages cell turnover. A bottle got delivered to me but with spillage so beautymnl promptly agreed to replace it, so points for that. The product was slightly yellow when I first opened it and a bit sticky when applied. I used it every other night after cleansing and essence. Then stored it in the refrigerator, in its box, as recommended. Not sure if it was because my skin really needed a break from all the products, or if it was too sensitive to vitamin c, but after a month or so of still getting pimples and not seeing much of an improvement, I stopped using it. Also noticed that my fingertips started to have a yellow tinge eventually. It's now June 2018 and I just checked the bottle again last night and the remaining liquid (half bottle) is now very yellow even though the expiry date is officially still in July 2018. I'm not doubting its effectiveness though. I think this would work best if your skin has already healed and all you have to do is lighten pimple scars.

2 months ago
  • Skin Type Combination
  • Skin Tone Medium
  • Facial Features Morena
  • Age 24


I ordered because of the reviews! And It’s my first time to use a vit c serum. Sa unang application nagkapimple ako kinabukasan and parang gumaspang yung face ko :( pero ngayon lumiit na yung pimple and tinuluy-tuloy ko pa rin yung product. Siguro nabigla ang face ko sa product kasi di naman talaga ako nag-aapply ng kung anu-anong keme-keme sa face ko. As of now, hindi naman na ako tinitigyawat kaya tuluy-tuloy ko ng ginamit. Naggoglow na yung face ko pansin ng tricycle driver samin hahaha! Pag maubos yung cpg oil ko itry ko rin to sa ua ko hihi. Btw, I’m using it for almost 3 weeks!

3 months ago