The Mediheal Madecassoside Derma Serum is the brand’s upgraded “moisture and marks” serum, sold at Olive Young under the tagline “upgraded moisture-blemish serum.” It has been showing up in Korean blog routines since August 2026, mostly as an everyday hydrating step rather than a targeted treatment.
Mediheal is best known in Korea for sheet masks and toner pads, so a dropper serum built around its signature madecassoside line is a natural extension. Here’s what the official label shows and how Korean reviewers are using it.
Why It’s Getting Attention in Korea
Korean blog reviews of the upgraded serum began appearing in early August 2026, and Olive Young currently lists both a 50 mL bottle and a 50 + 50 mL set. Mediheal is also rolling the same derma serum line out in Japan this fall, according to Korean trade outlet The Guru.
The appeal in Korean posts is simple: one lightweight serum that covers hydration, calming, and the look of leftover marks. The three Naver reviews this article draws on describe it as a daily step that fits into an existing routine without much thought.
What’s in the Mediheal Madecassoside Derma Serum
The full ingredient list on Olive Young gives a clearer picture than the marketing does.
- Madecassoside at 1,080 ppm (about 0.1%). This is the purified compound from centella asiatica. Mediheal labels the serum “High Purity 98,” which refers to the purity of the madecassoside it uses, according to the brand.
- Niacinamide sits fifth on the list, right after the base ingredients. The serum is registered in Korea as a functional cosmetic, the category that covers approved brightening and anti-wrinkle claims.
- Hydrators and supporting ingredients include glycerin, panthenol, betaine, sodium hyaluronate, beta-glucan, and ceramide NP, plus several centella extracts.
- Essential oils. The list includes juniper (pencil cedar), patchouli, mugwort, and rosemary leaf oils. That’s worth knowing if fragrance-type ingredients tend to bother your skin.
Some Korean blog posts say the upgrade doubled the niacinamide level. Mediheal’s product page doesn’t state a niacinamide concentration, so we couldn’t confirm that.
What the Brand’s Testing Says
Mediheal’s product page lists several tests run in spring 2026 by a Korean skin research institute: a non-comedogenic test with 21 participants and a sensitive-skin irritation test with 32 adults, which the brand reports as an irritation score of 0.00. It also carries a 2026 “Excellent” seal from German testing service Dermatest.
In company-reported testing, Mediheal says the look of marks in breakout-prone areas improved by 17.03% after four weeks. Treat that as supporting product information, not a guarantee of the same result for everyone.
The bottle also uses a refill system. Mediheal’s product page says you keep the bottle and replace only the contents.
How Korean Reviewers Use It
The Naver reviews we looked at describe a watery, light serum that absorbs quickly and leaves a dewy feel without a tacky film. Their routines look similar:
- After toner, morning and night, before moisturizer and sunscreen
- Two or three thin layers on days when skin feels dry or stressed, since the texture doesn’t build up
- A thin double layer before foundation, so base makeup is less likely to cling to dry patches
- A rich cream on top at night for reviewers with drier skin
One reviewer in their 40s with dry skin described it as a serum they’d use year-round rather than swap out by season.
Who It May Suit — and Who Might Skip It
The serum may suit people who want a simple, lightweight hydrating step with calming ingredients and a niacinamide-based brightening angle, especially if heavier serums feel sticky.
It isn’t a replacement for a moisturizer on dry skin, and Korean reviewers themselves note it’s a daily serum, not a stand-in for stronger actives. If you react to essential oils, check the full ingredient list first.
What Stands Out — and What Remains Unproven
What stands out is how much is on the record: a disclosed madecassoside level, functional cosmetic registration, dated test conditions, and a refillable bottle at a mid-range Korean price.
What remains unproven is how much the upgrade changed compared with the previous version, since the claimed niacinamide increase isn’t stated on the official page. The 17.03% figure and the irritation score both come from brand testing.
Product Snapshot
- Product Name: Mediheal Derma Serum Madecassoside Moisture Blemish (Korean listing: Madecassoside Derma Serum)
- Brand: Mediheal
- Size: 50 mL
- Korean List Price: ₩26,000 at Olive Young (as of October 7, 2026); 50 + 50 mL set listed at ₩43,000
- Key Ingredients: Madecassoside (1,080 ppm), niacinamide, panthenol, betaine, sodium hyaluronate, ceramide NP, centella asiatica extracts
- Texture / Format: Watery serum in a refillable dropper bottle
- Best Suited To: People looking for a lightweight daily hydrating and calming serum
- Source & Sponsorship Note: Korean reviewer impressions are drawn from three Naver blog posts; we couldn’t confirm whether they were sponsored. Product specifications, price, ingredients, and test details were checked against Mediheal’s official listing on Olive Young.
Last checked: October 7, 2026