ost vitamin c serum review





OST Original Pure Vitamin Serum C20 rose to become one of Korea’s best selling vitamin C in 2012 and was known as the ‘red bottle’ in Korea. It managed to compete with other famous international skincare brands such as Sisley and Estee Lauder as the Top 3 Serums at the prestigious SURE BEAUTY AWARDS. So what is this OST serum all about ?


Features :

+ Includes pure Vitamin-C 20%
+ Whitening /Recovering trouble scars
+ Removing blackheads
+ Ranked the best selling item in Singapore No.1 commerce. (2012)


Most of the products with vitamin C out there contain less than 2-3% of Vitamin C, but this contains a whopping 20%. Vitamin C is known to be one the most powerful anti-aging antioxidant. It is also extremely well known in whitening products. I will be talking more in depth about this in the ingredients section.







As this is known as the ‘red bottle’ in Korea, therefore you expect the packaging to be all red but it is more like silver orange. It comes in a nice glass tinted jar which is important as Vitamin C is extremely easily oxidized by sunlight therefore the packaging is extremely important to slow down the oxidation process of the Vitamin C. Store the product in a dark, cool place. I keep mine in the refrigerator.

The packaging of the serum itself comes with a dropper. When newly purchased, the pipette is packed separately and the cap of the bottle is sealed. So make sure that you get a product that is sealed and with the pipette packed separately. This also ensures the freshness of the product as well as to avoid any oxidation of the product. You would have to fix the pipette into the bottle yourself.





Shows both the manufacturing and the expiry date on the box of the packaging.








The serum has the typical texture of a serum – gel like, watery. It does smell fruity and citrus-y which is refreshing. The slimy gooey texture does absorb rather quick but however, it really leaves a very sticky and uncomfortable after-feel which is absolutely uncomfortable.




The colour of the serum is colorless initially, but it will gradually turn orange-yellowish after a few weeks due to the oxidation. Therefore I strongly advice you use the serum up ASAP. I do have a few tips on how to avoid a sticky-goey after feel and how to use it up asap!


What I do is that I mix my toner with the serum on a 2 to 1 ratio. This helps in making the serum less sticky, and also aids in making the toner sort of like a booster. You can also mix this with your emulsion or cream. You can even mix it with your sunscreens or sun products as they help to boost the efficiency of sunscreen actives.





Hydration and Oil Test



As you can see below, there is hardly any oil in this product.



Hydration level did improve drastically upon application of serum. High scores of hydration level in both cases.








Stickiness Test



As mentioned earlier, the biggest weakness of this serum is the stickiness. As you can see, it is really sticky.




And the stickiness improves when it is mixed with a toner.








Ingredients : Water, Ascorbic Acid, Alcohol, Sodium Lactate, Butylene Glycol, Glucose, PEG-60 Hydrogenated Castor Oil, Sodium Hyaluronate, Bis-PEG-18 Methyl Ether Dimethyl Silane, Methylparaben, Diethoxyethyl Succinate, Phenoxyethanol, Ammonium Acryloyldimethyltaurate/VP Copolymer, Xanthan Gum, PEG-180, Gluconolactone, Camellia Sinensis Leaf Extract, Beta-Glucan, Rosa Davurica Bud Extract, Citrus Aurantium Dulcis (Orange) Oil, Zinc PCA, Panthenol, Niacinamide, Carthamus Tinctorius (Safflower) Flower Extract, Glycerin, Tocopheryl Acetate, Lecithin, Caprylic/Capric Triglyceride, Ubiquinone, Diisopropyl Adipate


As you can see from this photo below, a bottle of this serum is equivalent to the vitamin C in 120 strawberries, 200 oranges and 40 grapefruits. This OST Serum uses 20% of L-ascorbic acid which is one of the most stable forms of VItamin C.



Vitamin C as a cosmetic ingredient became popular when a scientific research paper published their results regarding L-Ascorbic Acid ( the type of vitamin C used in the OST serum ) being able to reduce UVB damage when applied to the backs of hairless pics. The evidence also indicated that photodamage or sundamage could be repaired with the topical use of Vitamin C. Later on, much more studies showed the wonders of VItamin C effect on the skin which helped in the popularity of L-Ascorbic as a skincare ingredient.

Vitamin C helps in different ways. It is a strong antioxidant which helps to neutralize the free radicals caused by the sun.It promotes collagen production, strengthens the skin barrier response, improve the appearance of sun-damaged skin, improves skin texture, etc.

Besides Vitamin C, the serum also contains other beneficial skincare ingredients such as the moisturizing sodium hyaluronate and rose extract, camellia extract, panthenol and beta glucan to soothe sensitive skin. It also contains antiaging  Niacinamide, Vitamin E and Coenzyme-Q10.


The bad : Alcohol, phenoxyethanol and methylparaben quite high up the list.







In all honesty, I wanted to give up after using this product for 3 days. I just couldn’t deal with the stickiness of the serum, but I forced myself to give at least one week to see if there were any difference with my acne and skin texture in general. I am glad I did because it did reap some positive benefits on my skin.


I have always had doubts when I see photos like this below. But when I took a photo to see the progress after two to three weeks, I was quite surprised to see the results. It not only helped in smoothening the general texture of my skin, but also helped in my pimples as well as the red spots. 




My before-after photo after 2-3 weeks :




While using this routine, I coupled it up with Skin&Lab Vitamin C Cream and used a very generous amount of the serum especially during the night period as I wanted to finish using up as soon as possible due to the quick oxidation of Vitamin C.


Other tips on how you could use the Vitamin C :

  • Mix it with your toner
  • Mix it with your cream – I was using it with
  • Mix about a whole pipette of serum with your normal sheet masks.


Those with skin problems, I would recommend to give this a try as it really is affordable compared to the Vitamin C serums which are at 20% concentration out there. For those without any major problems, I would recommend another Vitamin C serum as it is just tooo hard to deal with due to the texture of the serum. Those who are looking for a powerful skin brightening whitening duo can try the serum together with the Skin&Lab Vitamin C Cream.


The OST VItamin C Serum can be purchased here at Wishtrend at only USD24.99. The Skin&Lab Vitamin C can also be found here. You may also find some interesting promotions at Wishtrend on their Beauty Steal section here. And to top it off, Wishtrend has generously donated a special 15% discount coupon which is available for any purchase on Wishtrend.com, so if you have been wanting to try this or the other stuff available on Wishtrend, this is a time.


Coupon 15% Discount Code : 4S6KT1WZ ( For orders above $30USD )

Categories: beauty reviews, OST
Posted on by admin
  • Sunita

    I buy everything you review. -.-”

    • hopeinablog

      awwww not good at all ! ;)

      • Sunita

        Do you think that you will repurchase this? =) I have yet to get mine in the mail.

  • LaStrasbourgeoise

    I’m in love with this serum!

    • hopeinablog

      you didnt find it too sticky??

  • Laura

    Wishtrend really went full force with this vitamin-c serum thing, I’ve seen 5 other blogs with their wishtrend intro/vitamin c thing in the past couple of days!

    • hopeinablog

      indeed they have. They seem to really believe in the potential of this serum though!

      • Kevin J.

        Kiehl’s has a Vitamin C suspension product too, which they call the Line Corrector. I looked at the ingredients list for the samples which I had, and noted that it is very short and minimalist, but there is ascorbic acid in a phosphate form or something of that sort. It might be a trend that most skincare companies are picking up on after peptides and fruit acids.

  • yen

    hey hope, haven’t commented on one your posts in quite a while and don’t mean to be a party pooper with this one but MAP (magnesium ascorbyl phosphate) is more stable than l-ascorbic acid AND it doesn’t have that acidic/tingling effect l-ascorbic acid does; MAP is light- and oxygen- stable. hope all is well in shanghai :-)

  • Kevin J.

    Unfortunately, Vitamin C suspensions do not do as much to stop acne as much as lighten their marks. I was looking at your before and after pics inside this post, and wonder if you use an exfoliating wash with something like salicylic acid or lactic acid to prevent acne flares and breakouts? (I am basically past that age of breakouts, but if I do get occasional pimples, or post-pimple red spots, I normally use exfoliating face washes more frequently, alongside my normal skincare routine, and they help better than just relying on Vitamin C suspensions.)

  • jen

    Hi Hope, I love reading your beauty product reviews…. I wanna ask u what is the name of the machine u used to test the skin moisture? Where can I buy one? Are the result reliable? Thanks…

  • charlie

    This is really an awesome review!!! Good job and thanks!! xoxo

  • Liz

    Hi, I am 20 and quite a bit of acne and scaring, you mentioned of major problems, there is another Vitamin C serum that you would recommend, can you tell me what it is. Thanks

  • iqskincare.net

    This product uses very much natural ingredient like vitamin c serum and etc.it uses the good technique in packing and attractive packing of product.The result that has been shown in images it create good impact on my mind.

    Thank You,
    IQ Skin Care.

  • okidoki

    I have terrible hyperpigmentation/melesma on my cheek. Would the combination of the two vitamin c serums that you mentioned above would at least fade the spots on my face? Also how long it took you to see the effect of the serum on your face?

  • kokonut

    I have tried this vitamin c serum but I liked Maxlife vitamin c better. It gave me better results than the ost without the stickyness as well. also it did not crust like ost. they’ve been selling this product in japan and korea as I got mine through rakuten. however it seems like they are selling in online. i know they are an US based company. maybe you want to try out their vitamin c serum as well.

  • jenni

    where did u buy it in korea??

  • http://filipinamacbarbie.com/ Juvy FilipinaMacBarbie

    Very nice results! I just started using one.

  • Anita

    Just wanted to say that you don’t want to mix the vitamin C serum with anything. Some types of vitamin C needs an acidic pH to be effective, by mixing it with something else, you run the risk of altering the pH too much so that it’s ineffective.

  • Diya

    Hi Hope,
    I have just purchased the ost and the vit c cream. what order should I follow to use both together or can they be mixed? I have freckles, brown spots and hyper pigmentation marks as well as dark circles. Please advise.Look forward to hearing from you! Thanks.

  • Elle

    I bought the ost vitamin c serum and cream. I was really excited to try it for my acne. Unfortunately it break me out even more. I only have acne on my chin area. After using the ost serum for 5 days, I discovered small pimples on my forehead and cheeks. I stopped using it and use my trusted benton small bee essense to rescue it.

    • GTea

      How much did you use each day? Like a dime size or more/ less? I really want to try it since everyone seems to get good results, but I’m scared since I have sensitive skin. I also rely a lot on my Benton essence haha

    • Loli La

      maybe at first the underskin acne will go out then it will be cleared , im not sure but some treatments do that

  • Kame Kame

    I notice that it did fade your indented as well! did it? or because of the lighting? If it did, how long did you get those scars? Thank you :D

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