I’ve been testing Korean skincare for over five years now — from touring R&D labs to learn the science behind ingredients to making midnight mask runs through Seoul’s Myeongdong. So when I spotted the Medicube Deep Vita C Capsule Cream for under $20 during Amazon’s Prime Big Deal Days, it felt like finding a pot of gold at the end of a K-beauty rainbow.

Picture me, jet-lagged after a 15+ hour flight but determined, dragging my carry‑on through the winding streets of Seoul in search of the next glow‑giving formula. I’ve poked around Korean beauty labs, chatted with formulators in Gangnam and tried products that never even made it out of prototype. After all that, a deal like this feels extra special.

medicube Deep Vita C Capsule Cream

During regular times this cream already sits at a tempting $22, but on Amazon but during Big Deal Days? It’s even cheaper.

When a powerhouse vitamin C formula lands in the “under $20” zone, alarm bells go off in this beauty nerd’s brain. Plus, I reviewed nearly all of medicube, and this is one of my favorite formulas from the brand.

Bonus points: grab the medicube skincare device I love to pair with it, and it’s *chef’s kiss* even more.

Now, let’s talk about what makes this cream stand out (beyond its bargain price).

First, it’s not just a straight-up vitamin C cream. It uses a liposome capsule delivery system (hence “Capsule Cream”); you literally pop and blend capsules into a gel base so your vitamin C stays stable and fresh until the moment of use. That means less oxidation, which is critical because vitamin C’s performance degrades fast when exposed to air or light.

Ingredient-wise, it’s a party of brightening and skin health boosters. There’s 50 % sea buckthorn extract delivering carotenoids and vitamin E-friendly lipids; 5 % niacinamide for reducing discoloration, balancing the tone, and fortifying the skin barrier; and multiple forms of vitamin C, including sodium ascorbyl phosphate, ascorbyl glucoside, ascorbyl palmitate and 3‑O‑ethyl ascorbic acid to diversify the delivery and stability of that all‑star antioxidant. All in all, that’s a heavy-hitter lineup for a cream under $20.

How to apply

So, how do you apply this vitamin C skin-replenisher? First, always patch test (especially if you’re newer to acids or actives). On clean, toned skin, pump out 2 to 3 pumps (or the recommended amount per the packaging) and gently press or pat into your face using your fingertips. Because you’re blending capsules, you’ll want to swirl or press until it’s a uniform gel — that “pop and blend” action, so you’re not leaving uneaten bits of capsule on your face. This ensures more even absorption.

After that, if your skin is on the drier or thirstier side, follow with a lightweight moisturizer or hydrating toner to lock it in. Use it in the morning under sunscreen (vitamin C + zinc or broad spectrum SPF is a classic team) or at night. Just don’t layer it with harsh acids at the same time, unless your skin is very resilient.

Over my many years of testing, I’ve found that gentle layering and listening to your skin — rather than piling on everything — gives the most consistent results.

The bottom line

In all of that travel and testing, I’ve learned that a buzzy K‑beauty product is only as good as its formulation, concentration and delivery. The fact that medicube’s Deep Vita C Capsule Cream brings a smart capsule delivery, stabilized multiple vitamin C forms, barrier-friendly ingredients and a mid‑range price (especially on sale) tells me this isn’t just hype. It’s a strategy, made for real skin.

For someone like me who’s been scrutinizing textures in Seoul’s fluorescent labs and comparing glow results across lotions and essences, getting this for less than $20 feels like scoring a mini miracle.

Your Prime Big Deal Days FAQs, answered

What is Prime Big Deal Days?

This annual Amazon sale — which we like to call October Prime Day — is similar to the well-known July event: it’s a two-day blow out shopping event with deep discounts on bestsellers and everyday essentials. But the timing of this sale makes all the difference; shoppers can also score pre-Black Friday deals on top-rated toys and sell-out-risk gifts before the holiday rush.

How long does Prime Big Deal Days last?

Amazon’s fall Prime Day event only lasts two days. This sale starts on Tuesday October 7 at 12:01 a.m. PT and runs through Wednesday October 8 at 11:59 p.m. PT.

When does Prime Big Deal Days end?

Prime Big Deal Days 2025 ends on Wednesday October 8 at 11:59 p.m. PT, so east-coasters have until about 3 a.m. on October 9 their time to shop the deals.

Do you have to be an Amazon Prime member to shop?

Prime Big Deal Days is a member-exclusive sale event. Interested shoppers can grab a 30-day free trial to try Prime, and its many benefits, with no strings attached.

Prime Day vs. Prime Big Deal Days: What’s the difference?

Already familiar with July Prime Day? Then you’ll love Amazon’s fall version! Like its summer spectacular sale, Amazon’s Prime Big Deal Days offers major discounts for 48 hours, but with a bigger focus on holiday gifts, toys and tech to shop ahead of Black Friday and Cyber Monday.

What are the best deals?

From reporting on Amazon sales for years, we can tell you for certain that October Prime Day is the ideal period to stock up on household essentials, score great deals on gift-worthy items and toys, take advantage of Black Friday-level discounts on tech and appliances, refill your skincare empties, and comb through the massive catalog of Amazon best-sellers.

Is it worth it?

We certainly think so! October Prime Day is a great chance to score Black Friday-worthy deals on thousands of best-sellers, including everything from big-ticket tech to Post reader-favorite trash bags. Our team diligently sorts through all the offers to find you the very best items to grab on sale.

When is the next Prime Day?

Already wondering when Amazon’s next Prime Day is? Prime Day takes place in July each year, so it’s safe to assume it will take place in mid-July 2026 — similar to previous years. Can’t wait to shop more Amazon deals? Look out for Amazon’s Black Friday sales to kick off the holiday season in November.

Don’t miss Post Wanted’s around-the-clock coverage. Click here to find all of the best deals.