Just so you know, we share cookies

Thanks for visiting, beautiful! BeautyMNL use cookies to ensure that we give you the best possible shopping experience. If you continue, we assume that you're happy to receive all of our cookies. At BeautyMNL, we respect your right to privacy and ensure your personal information is kept secure. Read on for our Privacy Policy

Christmas Customer Service Schedule:

In observance of Christmas, our Customer Service Team will be offline on December 22-25. We will respond to inquiries when office hours resume on December 26, 10AM.

Unlimited Free Shipping until December 31, 2018

My Signature C Source

Payment options available:
  • Credit Card
  • Paypal
  • Bank Deposit
  • Cash on Delivery

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!

131 reviews

Share your experience with this product
4.2 out of 5
5 stars
4 stars
3 stars
2 stars
1 star
Certified Buyer
  • Skin Type Oily
  • Skin Tone Fair
  • Facial Features Chinita
  • Age 27

Been using this for years! <3

I've been using the same product for 4+ years already, under its old name C20, and up until now. Before Vitamin C serum was a hit locally, I'm already using it. It's one of my important skincare products because it reduces the inflammation of my pimples, blackheads, & whiteheads, and keeps them at bay. I've tried both dear Klairs Vitamin Serum & Wishtrend C21.5 before, but I always find myself going back to this item because both items feel either too lacking or too rich which causes millia in my eye area. It's my HG item <3 Prolly the only con for me would be its storage. I still need to keep it in fridge every after use. Aside from that, this item is a good level up for Vit C serum users who doesn't find Vitamin Serum suitable for them. If you want to play in the safe side, Klairs Vitamin Serum is a good starter, before going for Tiam Vitamin C Serum, which is a crowd's favorite for me.

1 day ago
Certified Buyer
  • Age 21

Best Vitamin C Serum!

I used to purchase Klairs but decided to give this a try after finishing the my previous serum and I’m very glad that I made the switch. It made my scars fade away and the healthy glow it gives my skin were unbelievable. Don’t forget to place it on the fridge for maximum effect.

4 days ago
Certified Buyer
  • Skin Type Combination
  • Skin Tone Fair
  • Facial Features Chinita


Love this!! I do recommend this for all skin types. It is effective BUT as time goes by it seems like it doesn’t do anything as much as before. DO Keep this in your refrigerator so that it’ll not spoil since it is pure vitamin C. Overall i’ll give 4/5

8 days ago
Certified Buyer
  • Skin Type Combination
  • Skin Tone Fair
  • Facial Features Chinita
  • Age 25

Goodbye pimple marks!

I have been using this for almost a year and this really helped lighten my pimple marks, almost as if I didn't have the breakout I had before I used it. Now, whenever a pimp pops up I'd use it at night bec it somehow calms it down. Haha I only used up 2 bottles of the serum up to date where at first I used it together with the crema until I finished the entire tub and serum and decided to just continue with the serum. 4 stars bec it really is too sticky even after drying but nonetheless effective

13 days ago
Certified Buyer
  • Skin Type Sensitive
  • Skin Tone Fair
  • Facial Features Mestiza
  • Age 34

Managed my mega extra sensitive skin

I had terrible acne for years which was heightened when I got pregnant. I tried expensive topical brands which kind of worked when I can afford it, but it was hard to maintain a VMV / Clinique / Kiehl's facial routine when you'd rather spend your money on milk and nappies. :) Also, I could not put anything on my face when I was pregnant, so now, mas kailangan ko yata ng masilya kaysa skin care set. I also had combination skin which was also prone to pimples (hair, pillows, dust, insects, dirty fingers, rubber by face masks, name it, it can trigger an acne breakout). I tried this product due to good reviews. Thanks to everyone, I kept it in the fridge as soon as I got it, made sure not to shake it, and it did not oxidize (change color or get sticky) until I am down to the last drop. I am glad to have purchased because although it did not really clear my scars, it did lighten them and somehow toned up my skin to even out the moisture / oil. I am glad that I spent a bit more to get decent skin. I am definitely going to purchase another bottle. Salamat! I give 4 stars only because I expect to have my scars cleared out, but although it takes time, it works naman, albeit not cleared out. :) I use it once a day only, at night before I sleep. It gives my skin a nice feel in the morning when I wash. :)

20 days ago
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

Related Stories See all stories

Customer's Pick: The 20 Best Reviewed Acne Treatments of 2018

Customer's Pick: The 20 Best Reviewed Acne Treatments of 2018

Part 5 of our customers' favorite products of the year!

6 Korean Serums You Need to Try

6 Korean Serums You Need to Try

As recommended by our regulars.

Ph 1
Promo skin genie (1)