My Signature C Source by Tiam

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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Top Reviewer

Yay! C20 is here! My HG in preventing hyperpigmentation, lightening pimple marks and evening my skin tone!

I am so thrilled that BeautyMNL finally has this and I'm waiting for it to be in stock again. I have been a user of this product for a couple of months now, so I am so happy that BeautyMNL has made it available locally. :) Just a few tips in the usage of this product and hopefully this can help users: (1) To make sure of its effectiveness, use it after cleansing with a low pH cleanser (like COSRx's Good morning low-pH cleanser). This Vit C product is a low pH dependent product, so if you do not prep your skin prior to its application, then you decrease or even negate its effectiveness. If you are not sure about the pH of your cleanser, then make sure that you have a prepping toner that lowers the pH of your skin before using this serum. (2) You need to wait 15-30 minutes before using other products in your skin care routine, especially those with niacinamide as niacinamide cancels out the Vit C. I know it's a long wait, but if you want to really see it working, you need to be diligent about this. (3) This product is an LAA type of Vit C, and is known to do "purging". You will experience some tingling on the skin, maybe even some heat. That being said, always wear sunscreen if you're using this during the daytime, or else you will experience more darkening of the skin or worse get sunburned. This is why it is recommended to use this product at night only. However, I have known others who use this during daytime, but they are COMMITTED to wearing a sunscreen (not just a bb/cc cream or cushion compact). If you can't commit to wearing a sunscreen during the day, then I suggest to use this product only at night. (4) Do your research when you are also incorporating other "actives" on your skin, like BHA's and AHA's. Unlike other skincare products, if you mess up with your "actives", you will end up with worse skin than before and it will take a long time to repair. (5) Finally, because this is an unstable form of Vit C, you need to store it properly as this is sensitive to light, heat and oxygen (air). I suggest to keep the box container and in-between uses, store it in your refrigerator. That way, your serum will last longer. Good luck!

over 1 year ago
Top Reviewer
Certified Buyer


LOVE. Got this when it was on sale for around 800 bucks. I have been using it for two weeks already and I am very happy! First off, if you check online this is a very popular vitamin C serum. Second, despite it's popularity and effectiveness, it's reasonably priced. A review here said that it used to be a lot cheaper but to be honest I'm willing to pay this current price for the quality. Other vitamin C serums on par with this one would easily cost over P3,000 (Kiehl's and Mario Badescu for example), so this is a steal! Anyway, I use this with Pixi Glow Tonic first, wait 20-30 minutes, apply a few drops of this, and wait another 20-30 minutes before I moisturize. The waiting time are supposed to let your skin settle into the product you used first, and adjust its pH, before you layer another for maximum effect (Google this!). My dark marks gave reduced significantly and any isolated break out doesn't last very long! Skin texture has improved as well. Please always have this Beauty MNL (and don't raise the price again lol)!

over 1 year ago
Certified Buyer


I have oily skin with small dry patches around my nose and chin. My skin also has a problem with healing scars from pimples i or my husband pop sometimes (i mean, who's not tempted to get rid of pesky zits?). It takes months and months for those dark brown spots to fade and i was DYING to get rid of them coz i look like i have a really bad case of acne when i'm not wearing my trusty foundation and concealer. BUT, when i tried this, i noticed that my dark marks lightened just after 3 days! The scent sets me off a bit when i apply it though but it fades when i let it set for 20 mins and apply my moisturizer. I'm 2 weeks in now and it significantly helped my complexion and i don't have as much breakouts as i did before. Can't wait to see more improvements in the upcoming weeks. And oh, now i can go out with just sunscreen and transluscent powder on. Yey! Girls, get one! Now!

over 1 year ago
Top Reviewer

Potent Stuff

I am such a believer in Vitamin C for great skin. However, Vitamin C is so sensitive... so you need to a lot time when applying it... And because I wanna take full advantage of the benefits of this product, I only use it at night when I know I've got nothing else to do. I use this after my shower, making sure my face is dry - free of water so as not to dilute the product. Then I take 2-3 drops, rub my palms and pat it on to my face, avoiding my eyes and areas near my nose and lips are that extremely sensitive. I use it alone so as not to counteract the Vitamin C content... And I make sure to use sunblock the day after. Vitamin C is known to brighten the skin - even out dark spots and I've noticed my sun spots lighten since 1 month of thrice a week use. I find the formula of this one super potent, thus, worth the price. I highly recommend!

over 1 year ago
Certified Buyer

If it's overnight results you need, look no further

I thought I'd step up my Vit C game to 20%, coming from 5% KLAIRS Freshly Juiced Vitamin C Serum, and boy am I glad I did. Deep scars and hyper pigmentation healed in less that 2 weeks for me, which usually takes months, and my usual monthly acne spurts were definitely under control. A couple of fair warnings tho, this serum has an unstable kind of formula and definitely needs to be refrigerated to extend shelf life. Therefore, the entire bottle after initial opening needs to be consumed in 3-4 months or before the liquid oxidizes and therefore loses its potency, and is not good for travel. Also another heads up, this will explode a little bit when first opened which I assumed is due to courier routine. Just be sure there is a lot of skin surfaces available to apply this on so no product goes to waste, hehe

6 months ago
Certified Buyer

No need to use foundation or concealer

I have been using this serum on my face for more than 2 months now and my skin has never been better. I have acne-proned skin and had acquired a number of acne marks from previous breakouts and this product has helped reduced their appearance in just a few weeks. It also brightened my face. Although my skin is far from being perfect, I am proud to say that I can get away without foundation or concealer now. I only apply sunblock, cheek tint, do my brows and I'm all set. This product has an orange scent to it but disappears quickly after application. Also, a little goes a long way. I'm towards my 3rd month of using it and I still haven't consumed half of the bottle. I store it in the fridge for added shelf life.

6 months ago