FOR THOSE who barely passed 10th grade biology, reading skincare ingredients might feel like another midterm you forgot to study for. BHA is good for oily skin. Vitamin C is good for dark spots. Cica is good for sensitive skin...or was it Centella asiatica? Trick question: Those are actually the same thing. The world of skincare seems to get more and more confusing these days; various brands compete to sell you their products by advertising the next magic ingredient that will get rid of your acne or repair your skin. But what is being advertised to you might not always tell the whole story; the benefits of different ingredients are often anecdotal, with few clinical trials to back them up. Here is the science behind this overwhelming selection of ingredients so you can understand what exactly they are doing to your skin.

  

   The first ingredient on our list is BHA, and yes, it is good for oily skin. BHA stands for beta hydroxy acids, the most common one being salicylic acid, everyone’s favorite acne-fighter. Because it is oil-soluble, it is able to penetrate the outermost layer of your skin and help you exfoliate as well as dissolve and loosen the gunk in your sebaceous follicles*. BHA is found in most acne-fighting skin care products, though a cult favorite is the COSRX BHA Blackhead Power Liquid.

   Another popular ingredient is AHA, or alpha hydroxy acids. This family of acids includes glycolic acid, derived from sugarcane; lactic acid, made from sour milk; and mandelic acid, which is derived from almonds, according to Healthline. Unlike BHA, AHA is water-soluble, so it works on the outer layer of your skin rather than penetrating deeper**. In milder concentrations, it is used as a mild exfoliant, and in stronger concentrations it is used as a chemical peel***. It also helps stimulate collagen production by fibroblasts, which are collagen-producing cells in the skin, according to Dr. Kenneth Howe in an interview with Byrdie. However, AHA can also make your skin more vulnerable to damage from UV-rays; there have been conflicting studies on whether AHA can do more damage to your skin than it brings benefits****.

   You have probably seen hyaluronic acid in a number of serums and sheet masks; it is actually something our skin naturally produces to maintain moisture*****. It is a hydrophilic molecule that can hold a thousand times its weight in water molecules, and when used on your skin, it can help keep your skin moisturized throughout the day, according to Dr. Rachel Nazarian in an interview with Harper’s Bazaar. However, the key is picking the right product, as the molecule is often too large to penetrate the skin—otherwise, it just sits on top of the skin “without it being helpful,” said Nazarian.

   Everyone knows Vitamin C is good for your immune system, but should you also be putting it on your face? People seem to think so; Goodal’s Green Tangerine Vitamin C Dark Spot Serum has recently been advertised in the most popular products section of Olive Young, though Vitamin C has been a widely talked about ingredient in skincare for a long time. The Dear Klairs Freshly Juiced Vitamin C Serum is fairly popular as well. Vitamin C is touted to brighten your complexion and fade dark spots, including acne scars, and like hyaluronic acid, it is naturally found in the skin. According to a paper published by the U.S. National Institute of Health, it promotes collagen production, reduces scar formation when used in wound healing, and inhibits melanin production, melanin being the pigment that gives skin color. However, the paper suggests that delivering Vitamin C to the skin by topical application “remains challenging,” so it is unclear how effective Vitamin C skincare products can be. 

 

   Mugwort, also known as Artemisia princeps, seemingly popped up in products out of nowhere, including Allure Korea’s Best of Beauty pick, the Hanyul Pure Artemisia Deep Cleansing Oil. It is a leafy green herb that is a member of the same family as tarragon and wormwood. In South Korea, mugwort is regarded as a healing herb and can be found in rice cakes, teas, and baths. According to Korean myth, a bear and a tiger who wanted to become human were instructed by the son of Heaven to stay in a cave for 100 days with only garlic and mugwort. Only the bear succeeded and was turned into a woman who later gave birth to Dan-gun, the founder of the first Korean dynasty. Dr. Rachel Lain told Allure that trials have shown that mugwort acts like an antioxidant, which helps prevent skin damage caused by UV rays from the sun. Though clinical trials to test its effect on acne have not been done, it has been proven to help decrease inflammation and kill bacteria, according to cosmetic chemist Ginger King in an interview with Allure.

   Cica has seemingly made its way into every other Korean skincare line; Dr. Jart+ has an entire Cicapair line filled with cica-infused products. You might have seen it referred to by its scientific name, Centella asiatica, but know that they are the same thing. It is a leafy green herb filled with amino acids, beta-carotene, fatty acids, and a whole myriad of vitamins—C, A, B1, and B2, according to Dr. Shari Marchbein in an interview with Allure. Cica has been used in Chinese medicine for centuries to treat wounds and burns, and it is sometimes referred to as “tiger grass” because tigers rub it on their wounds to heal themselves, according to Allure. In terms of scientific studies, one found that cica significantly improves skin hydration and reduces moisture loss, and another found that it speeds up wound healing and reduces inflammation******.

 

   The Mizon Snail Repair Intensive Ampoule and COSRX Advanced Snail 96 Mucin Power Essence, which touts having a 96 percent snail secretion filtrate, are famous in the skincare world. It claims to do a number of things, from repairing skin damage and reducing the appearance of wrinkles to preventing acne breakouts and fading acne scars. And it is not just skincare; a Japanese skin clinic launched “snail facials” in 2013, where you can let snails crawl directly on your face*******. Apparently, it is the power of snail slime. Most of the snail mucin for skincare comes from Cryptomphalus aspersa, the common garden snail. According to Dr. Sejal Shal in an interview with Allure, snail mucin contains a mix of peptides, glycosaminoglycans, hyaluronic acid (a previously mentioned ingredient for skin moisture and collagen production), and metal ions such as zinc, copper and iron. Because snail mucin is produced under stress, it is meant to repair or protect the snail from injury — meaning it could do the same for your skin, according to the Quarterly Journal of Microscopical Science. Another ingredient, allantoin, supposedly soothes irritation. A scientific study found that snail mucin reduced melanin production, which is likely why it can be used to treat hyperpigmentation********. Another study even found some anti-aging effects in terms of reducing wrinkles and improving skin elasticity*********. Due to the limited number of research studies however, specifically related to snail mucin use in skincare, most of the skin benefits attributed to snail mucin are theoretical based on what we know about its composition.

   For those with oily skin, clay seems to be a ubiquitous member of your skincare products—specifically, volcanic ash clay. Innisfree has a whole line of products made from volcanic ash, including the Super Volcanic Pore Clay Mask and Jeju Volcanic Pore Clay Mask. They are supposedly made from “minerals released by volcanic explosions in Jeju,” according to its website. Other commonly used types of clay are bentonite clay, which is popular in the United States, as well as kaolin clay, a mineral clay which derived its name from the Chinese village of Gaoling. The main benefit of clay seems to be its ability to absorb oil like a sponge. Volcanic ash particles are tiny and porous, adding to its ability to soak up things on your face. They also have antioxidant and antibiotic properties, according to Dr. Adarsh Vijay Mudgil in an interview with Byrdie. However, overusing volcanic ash and clay products can also make your skin too dry, said Mudgil, so picking the right product that hydrates as well is important.

 

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   At the end of the day, everyone’s skin is different. Someone else’s perfect nighttime skincare routine might be the cause of your latest breakout. With a better understanding of what is in your skincare products, you can be a better judge of what is right for your own skin.

 

 

*Healthline

**Healthline

***Healthline

****Molecules

*****Dermato-Endocrinology

******BMC Complementary and Alternative Medicine

*******Telegraph

********Biomedicine & Pharmacotherapy

*********Korean Journal of Dermatology