MediCube Kojic Acid Turmeric Resurfacing Toner

Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.

AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.

Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.

Overall, glycolic acid helps with:

Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.

To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).

The pH and concentration of a product are key to its effectiveness:

It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.

Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.

If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.

Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.

Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.

Read more about some other popular AHA's here:

Curcumin also has anti-inflammatory properties and can help soothe skin and reduce irritation. On top of that, curcumin has been shown to help prevent hyperpigmentation from sun damage.

The anti-microbial property of turmeric can make it effective in treating acne. This property has also been shown to help regulate the production of sebum.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

Studies show coating UV filters with dextrin prevents these ingredients from being absorbed. This helps UV ingredients last longer on the skin.

Studies have found adenosine may also help with wound healing.

In skincare products, Adenosine is usually derived from yeast.

By latching onto the copper that the enzyme tyrosinase needs to function, Kojic Acid prevents less pigment from being made. It's so well-established that researchers regularly use it as the go-to benchmark when testing new brightening ingredients.

Some other perks include documented antioxidant and antimicrobial properties. The The CIR (Cosmetic Ingredient Review) Expert Panel concluded Kojic Acid is safe for use in cosmetic products at concentrations up to 1% and the EU's SCCS (Scientific Committee on Consumer Safety) considers it safe as a skin lightening agent at concentrations up to 0.7%.

One thing to know about Kojic Acid is that stability is its weak spot; it is sensitive to light, heat, and air exposure and will oxidize/turn brown in formulations. Its derivative, Kojic Dipalmitate, was developed as a stable alternative.

Some individuals have reported contact sensitization so be sure to patch test if you have reactive or sensitive skin.

Fun fact: It was first discovered in 1907 and naturally occurs in the production of sake, soy sauce, and miso.

When exposed to air, these two compounds become strong allergens. This ingredient exhibits cytotoxicity at low concentrations; amounts of 0.25% have been shown to damage skin cells.

A study from Japan found this ingredient caused lavender sensitivity after widespread exposure.

Lavender essential oil has some antimicrobial, antibacterial, and anti-inflammatory properties. However, the cons of this ingredient may outweight the pros.

More research is needed to confirm lavender essential oil's effects when used in aromatherapy.

Lavandula Angustifolia is known as the English Lavender and famous for creating purple fields in Provence, France.

The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.

When used topically, Citrus Aurantium Bergamia Fruit Oil is a photosensitizer due to the furanocoumarin content. Furanocoumarins absorb UV-A and cause phytophotodermatitis; this can look like redness, blistering, and lasting brown pigmentation on sun-exposed skin.

Due to this, this ingredient is capped at 0.4% in leave-on products applied to sun exposed skin.

Many modern formulas used a "furanocoumarin-free" version that sidesteps the phototoxicity issue, but still contains the fragrance allergens.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

Because hydrolyzed hyaluronic acid is smaller in size, it can slip past your outermost layer of skin more easily than full-sized HA.

Most formulations will combine all sizes to get the best of both worlds.

Typical usage levels range from 0.01-1%. Any percentage higher than 2% might become goopy and tacky.

Read about common types of Hyaluronic Acid here:

The only catch is that HA isn't a single thing; it actually comes in a wide range of molecular weights (~50 - 2,000+ kDA) and size matters.

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

This is why the best HA serums blend the two sizes together so you get the best of both worlds.

The majority of cosmetic HA is produced by bacterial fermentation, typically using Streptococcus or Bacillus strains. Typical use levels in skincare sit around 0.1-2%.

A clinical study using a 0.2% low-molecular weight HA gel showed improvement in facial seborrheic dermatitis with excellent tolerance.

These are some other common types of Hyaluronic Acid:

A follow-up clinical trial found that a topical crosslinked HA serum applied after fillers, microneedling, or chemical peels was well-tolerated and enhanced skin quality at 14 / 28 days.

More recent research suggests that concentrations as low as 0.03% can act as a penetration enhancer for other skincare actives.

Fun fact: PH is used in eye drops and injectable treatments for joint disorders. It has lubricating and tissue-repair properties.

According to studies, low molecular-weight hyaluronic acid can:

One study from 2011 found ultra-low weight HA to show pro-inflammatory properties. Another study from 2022 found it to downregulate UV-B induced inflammation.

Hydrolysis is a process of changing a molecule using water or enzymes.

This ingredient is water-soluble.

This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

This ingredient is an emollient, emulsifier, and penetration enhancer. As an emollient, it helps soften and hydrate skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

Hydrogenated Lecithin can form tiny spherical structures made of phospholipid bilayers called liposomes. These liposomes are able to capture compounds inside their structure and deliver them through the skin barrier.

Because phospholipids are a natural component of our cell membranes, this ingredient is inherently compatible with skin.

A 2021 study found lecithin-based surfactants were less harsh and more tolerable comared to Sodium Lauryl Sulfate (SLS).

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Caprylic Triglyceride is made by combining glycerin with coconut oil, forming a clear liquid. Though it behaves like an oil, it is not technically one due to its chemical composition. It is very stable, resistant to oxidation, and unlikely to go rancid. In practice, that translates to a long shelf life and a consistently elegant skin feel.

While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Be sure to patch test if you have concerns.

Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.