What Is It:


Missing the K-beauty cult favorite OST C20 for its lightening, brightening powers? Well, stop missing it and get on this newer, better OST C20, now rebranded as Tiam My Signature C Source.  Formulated with the best, most effective vitamin C out there (ascorbic acid, and 20% of it!), the Tiam C Source offers four main benefits: 1) It brightens and evens skin tone, 2) It fades post-inflammatory hyperpigmentation (PIH, those discolored scars from healing acne), 3) It minimizes the appearance of pores by clearing out blackheads and reduces fine lines, and 4) It boosts collagen production. The result? Brighter, smoother, firmer skin. Consider this your facial in a bottle.
Important note: Make sure to keep this product in the fridge to prevent it from leaking or changing color!


Our insight:


Because vitamin C is notoriously unstable, store in the fridge, or at the very least, keep away from heat and light whenever possible. Also, avoid mixing with high levels of AHA, BHA, or retinoids to minimize irritation.


How to use:


Apply after your toner all over the face or on trouble areas. Make sure to wear a broad spectrum, SPF 30 or higher sunscreen during the daytime.


Ingredients:


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


Brand info:


You can expect Tiam to become one of your go-to favorite brands. After all, it’s the new rebrand of the cult favorite OST (hailed for their vitamin C serum C20). With active ingredients targeted for results, Tiam is always looking to create real solutions for your skincare concerns.


What Is It

What Is It:


Missing the K-beauty cult favorite OST C20 for its lightening, brightening powers? Well, stop missing it and get on this newer, better OST C20, now rebranded as Tiam My Signature C Source.  Formulated with the best, most effective vitamin C out there (ascorbic acid, and 20% of it!), the Tiam C Source offers four main benefits: 1) It brightens and evens skin tone, 2) It fades post-inflammatory hyperpigmentation (PIH, those discolored scars from healing acne), 3) It minimizes the appearance of pores by clearing out blackheads and reduces fine lines, and 4) It boosts collagen production. The result? Brighter, smoother, firmer skin. Consider this your facial in a bottle.
Important note: Make sure to keep this product in the fridge to prevent it from leaking or changing color!


Our insight

Our insight:


Because vitamin C is notoriously unstable, store in the fridge, or at the very least, keep away from heat and light whenever possible. Also, avoid mixing with high levels of AHA, BHA, or retinoids to minimize irritation.


How to use

How to use:


Apply after your toner all over the face or on trouble areas. Make sure to wear a broad spectrum, SPF 30 or higher sunscreen during the daytime.


Ingredients

Ingredients:


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


Brand info

Brand info:


You can expect Tiam to become one of your go-to favorite brands. After all, it’s the new rebrand of the cult favorite OST (hailed for their vitamin C serum C20). With active ingredients targeted for results, Tiam is always looking to create real solutions for your skincare concerns.


Beauty Expert Reviews 5

What's a Beauty Expert?
Beauty Experts consist of estheticians, cosmetologists, makeup artists, and beauty professionals who supplied documented proof of their industry experience.

Great for fine lines and wrinkles!

Great for treating aging skin, sun damage and uneven pigmentation. Can't beat that price either!

bluenighttian

For me , this is quite magical to use at night.
I put it on after I cleanse and then a simple moisturizer to follow.
I wake up brighter the next morning.
Pretty useful for fading acne scars.

redcyphers

I'll definitely have to try this. Ascorbic acid + alcohol seems like a sensible combo (enhanced penetration?)

thhl85

I have a love - hate relationship with this one.
LoooOve that is actually does ALL the things it claims to do, but hate that it leaves a sticky/tackiness feeling on my skin.

Related Article

October 10, 2018

This Cult Fave Vitamin C Serum Is Back — Rebranded But With the Same Formula

When K-beauty brand Tiam announced that they had rebranded the cult vitamin C serum OST C20, but kept the same formulation, skincare lovers everywhere rejoiced.