Review: OST/C20 Original Pure Vitamin C20 Serum

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Today I'd like to introduce you to a wonderful skincare product that gives me that warm and fuzzy feeling: C20 Original Pure Vitamin C20 Serum. (Literally. It tingles for a few minutes after I apply it.) In all seriousness though this is a good Vitamin C serum available at a very reasonable price (in my opinion), so read on if you're in the market for such an item!

Quick note about the name: Some of you may have seen a similar-looking product branded as OST Original Pure Vitamin C20 Serum—it's the same thing as this. They rebranded it as "C20 Original Pure Vitamin C20 Serum" earlier this year. Not sure why as the new name is a bit redundant, but in any case it's the same thing inside the bottle.

Speaking of bottles, OST/C20 serum comes packaged in a standard glass vial to prevent leaking, but there is a handy-dandy dropper in the box for you to use once it's safely unboxed and in your hands.

Fancy. Ingredients:

The only weird thing I see on this ingredients list is Niacinamide—not a bad ingredient by itself, but my understanding it loses its effectiveness when mixed with Vitamin C, and can sometimes cause flushing if present in an acidic formula (which this is). So why is it in there? Shrug.

According to the product page on WishTrend, this serum is meant to:

• Whitening (in the sense of overall skin tone brightening)
• Recovering trouble scars (reducing PIH/post-acne marks)
• Removing blackheads (by exfoliating, I imagine?)

The form of Vitamin C present in this serum is Ascorbic Acid, which is supposedly makes up about 20% of the overall formula. I obviously don't have a way of testing that, but what I can tell you is that I tested a bit of the formula on some home testing pH strips, and got a result of about 3 (accuracy not guaranteed, of course). That would make this product acidic enough to actually penetrate the skin, which makes me think the blackhead-reducing claims are probably true. (I don't have an especially large amount of blackheads myself, so it's difficult for me to notice real results in that regard.)

The texture of the serum is sort of viscous and slippery—thicker than water, but still very runny. It has a very faint yellowish color and smells vaguely sour (like citrus, not rotten milk). It's actually a good idea to keep an eye on the color of your Vitamin C serum, because if it darkens noticeably that probably means the product has oxidized and is no longer good to use. Make sure to store the product in its original bottle (which is made of dark glass) and keep it away from heat/sunlight to increase its longevity. With that said, the shelf life of the product is still only about three months, so use it while you can!

Aaaaaanyway. I use this serum as part of my daytime routine because I don't want it to interact badly with the Tretinoin/Paula's Choice BHA I use at night. (FYI, I used to use the BHA during the day, but now I alternate it with Tretinoin as part of my nighttime routine. You don't want to mix the two. Exciting!) I think C20 might actually be better to use this as a nighttime product as well because the Ascorbic Acid could get broken down by exposure to the sun, but if you're the indoorsy type (like me!) that is perhaps not such a big issue. Plus sunscreen and floppy hats are a thing.

Here's where it fits into my routine:

• Wake up
• Lament on the onset of the day
• Cleanse face (I usually use CeraVe Foaming Cleanser in the morning, if anyone cares)
• Apply a few drops of OST/C20 serum to face
• Experience a mild to moderate tingling sensation from the serum
• Wait 10-15 minutes for the tingling to neutralize
• Apply other skincare (moisturizers and whatnot)
• Lament the onset of the day

Some people probably apply this over or mixed with a toner, but I like to just go all in like a wild woman. The result is a slightly tingly, flushed feeling immediately after application, but I find that it goes away after a few minutes. YMMV so be sure to test patch if you have sensitive skin.


Overall impressions:
I've been using this serum for about a month now and I *LOVE* it! I have no idea if it's doing anything to remove blackheads, but my skin definitely feels supple and my overall complexion looks a bit brighter, in my opinion. I also had some acne scarring which seems to have faded a bit more rapidly than normal since introducing this into my routine. OST/C20 is the third Vitamin C serum I've tried, and so far I think I like it the best—jury's still out on Paula's Choice C15 serum (another popular choice that I have dabbled with but will test more extensively and review in another month or so). But the bottom line is that I do think OST Original Pure Vitamin C20 Serum is effective and quite reasonably priced too.


Where to buy + coupon codes:
You can purchase OST/C20 Original Pure Vitamin C20 Serum from WishTrend, where it is currently on sale for $14.99 plus free shipping (regularly $24.99 for 30ml). Even better yet, new customers can get a $5 voucher to use towards their purchase of $30+ by entering my referral code in the "Friends Invitation Program" field when signing up or filling out the "Additional Information" section of their profile: 252963208. All orders over $69 ship free at WishTrend, just FYI.

What do you think of OST/C20 Original Pure Vitamin C20 Serum? Do you have any favorite Vitamin C serums you'd recommend?


Disclosure: The item featured in this post was provided to me for review purposes, however any opinions expressed above are honest and my own. I did not receive any other form of compensation. This post contains affiliate links. For more information, check out my full disclosure policy.