The Beautictionary: Everything You Need to Know About Beauty’s Buzziest Ingredients
There are few things I love more than flexing my skincare ingredient knowledge. Mostly because it makes me feel very smart and like my high school chemistry lab partner didn’t have to do all of our labs on his own because I somehow messed up every single time (which I did). Sorry Jonny.
But science class trauma aside, it’s also helped me really understand what I’m putting on my skin. Let’s be real: an ingredient list filled with hard-to-pronounce words is kind of unsettling—at least for the control freak in me.
I don’t understand why this information isn’t readily available for the masses, so I figured I’d do just that. Allow me to introduce the poorly named but highly informative Beautictionary. Here, you’ll find a comprehensive list of trendy and oft-used skincare ingredients. Each ingredient is broken down by type, benefits and side effects, who should use it, how often it should be used, and other ingredients that should not be used with it.
Alpha Hydroxy Acid (AHA):
Type of Ingredient: Acid/chemical exfoliant
Main Benefits/Side Effects: AHAs, first and foremost, exfoliate the top layers of skin by dissolving the “glue” that holds dead skin cells together and helping them slough away. This generally results in radiance, a smoother texture, and fewer/lighter dark spots. AHAs also promote collagen development, though none more than glycolic acid (more collagen means fewer fine lines and wrinkles.) Several AHAs are humectants, which means they attract water to the skin.
There are a ton of different AHAs on the market, all of which differ in size, penetration, and potency. A general rule of thumb is that the smaller the molecule, the deeper it can penetrate the skin, which means both increased efficacy and increased likelihood for irritation.
Who Should Use It: Because there are so many different types of AHAs, really anyone can benefit from using them. It’s all about finding the right type and concentration for your particular needs.
How Often Can You Use It: It really depends on the particular acid and the particular person using it. In general, I suggest starting slowly, using any AHA only once or twice a week and gradually increasing frequency as skin can tolerate.
Don’t Use With: Retinoids
Arbutin:
Type of Ingredient: Brightener
Main Benefits/Side Effects: Arbutin, which is derived from natural ingredients, prevents the formation of melanin, thus lightening and brightening the skin. It’s also gentle on the skin thanks to its slow-release active component. Arbutin also has some sun protection properties given that it can reduce the degree of skin darkening after sun exposure.
Arbutin is particularly appealing thanks to its versatility—the product is completely safe to use with all other skincare products and can be used twice a day.
Who Should Use It: Really anyone can use Arbutin, though it might be particularly appealing for those with sensitive skin who can’t use other brightening ingredients.
How Often Can You Use It: Twice a day, every day, baby!
Don’t Use With: N/A
Azelaic Acid:
Type of Ingredient: Chemical exfoliant
Main Benefits/Side Effects: Azelaic Acid is a bit of an overachiever. Not only does it gently exfoliate and remove dead skin cells, it’s also comedolytic (prevents comedones AKA pimples.) It reduces inflammation and soothes irritation while simultaneously evening out skin tone and treating rosacea. I told you, it’s a lot.
Though it’s possible to experience slight irritation, Azelaic acid is, by and large, a mild type of acid. Another major benefit of Azelaic Acid is that it’s one of the few acne treatments safe for pregnant women to use. It’s also gluten-free for all of you who pretend to have Celiac!
Who Should Use It: Acne-, rosacea-, and hyperpigmentation-prone skin will benefit most from Azelaic Acid.
How Often Can You Use It: Since it’s a more mild acid, I think most people can probably get away with using it once every other day—though I might stick to three days a week to be safe.
Don’t Use With: N/A
Bakuchiol:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: Bakuchiol is generally seen as a more natural, less irritating version of retinol (see below.) So, much like retinol, bakuchiol evens skin tone, reduces the appearance of fine lines, speeds up skin cell regeneration, and helps soothe and heal skin.
Unlike retinol, it’s non-drying/irritating, safe to use twice a day, and suitable for all skin types.
Who Should Use It: Discounting specific allergies, bakuchoil is generally safe for all skin types.
How Often Can You Use It: It’s technically considered safe to use twice a day, every day, but I am very cautious about overwhelming the skin, so I’d probably say to use once every other day.
Don’t Use With: While it won’t cause any irritation, glycolic acid could degrade the formulation.
Benzoyl Peroxide:
Type of Ingredient: Anti-bacterial
Main Benefits/Side Effects: Benzoyl Peroxide is for all my fellow acne-havers. The organic ingredient kills acne-causing bacteria, removes excess oil, and removes dead skin cells.
That being said, benzoyl peroxide can be quite drying and irritating, sometimes leaving behind patches of extreme dryness and/or redness
Who Should Use It: Anyone looking to treat mild to moderate acne.
How Often Can You Use It: Up to twice per day, at absolute most. But it’s important to note that you should only be using one form of benzoyl peroxide a day. So, if you use a benzoyl peroxide cleanser in the morning, don’t use a benzoyl peroxide spot treatment at night.
Don’t Use With: Other benzoyl peroxide products. It also may reduce the efficacy of vitamin C products when used at the same time, so try to separate the two.
Butylene Glycol:
Type of Ingredient: Humectant/Solvent/Emollient
Main Benefits/Side Effects: Butylene Glycol fucks, and by that I mean it improves penetration. Albeit, I am talking about a slightly different type of penetration than the one that comes to mind. By breaking down hard-to-dissolve active ingredients, butylene glycol helps products reach deeper into the skin and thus perform more effectively.
Beyond its active sex life, butylene glycol attracts water, pulling in hydration to the outermost layer of skin. It also creates a barrier on the skin, which prevents water loss and softens and conditions the skin.
I do think it’s important to mention that butylene glycol is an organic alcohol derived from petroleum and used in antifreeze, which is definitely a little freaky. That being said, it is absolutely not considered to be toxic—the EWG rates propylene at a whopping 1 out of 10 on their danger scale (10 being the most hazardous and 1 being the least.) Just remember that even the safest of ingredients can cause irritation for certain people.
Who Should Use It: Anyone looking to effectively moisturize the skin.
How Often Can You Use It: Generally safe for daily use.
Don’t Use With: N/A
Caffeine:
Type of Ingredient: Anti-inflammatory
Main Benefits/Side Effects: There’s a ton of hype around caffeine in skincare, which unfortunately means there’s also a ton of contradicting information about caffeine. It is perhaps best known (at least in the skincare industry) for its de-puffing properties. It’s widely used in under-eye creams and serums, though it’s important to note that the results are immediate, not long-lasting.
Caffeine actually does quite a bit more for the skin though. It reduces cellulite, protects the body from free radicals (via antioxidants), and helps with collagen production. Because it increases circulation, caffeine can cause some redness.
Who Should Use It: People concerned about wrinkles and/or signs of aging.
How Often Can You Use It: It’s usually used one a day, in the mornings.
Don’t Use With: N/A
Castor Oil:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: This thick, goopy oil has a few key benefits. It’s likely best known for helping speed up hair growth, but it also protects against wrinkles, soothes problematic skin, and fending off split ends.
Castor oil also helps stimulate the body’s own production of collagen and elastin, which can ultimately soften and hydrate the skin. However, it’s generally suggested to stay away from castor oil during pregnancy because it can apparently induce labor (which is…wild.)
Who Should Use It: People with problematic skin; people who want to prevent wrinkles.
How Often Can You Use It: Once a week (can use more often on hair.)
Don’t Use With: Possible irritants.
Ceramides:
Type of Ingredient: Moisturizer
Main Benefits/Side Effects: I’m a huge fan of ceramides, thanks to their wide-reaching benefits. Ceramides restore the skin barrier (which can be compromised by aging, the overuse of exfoliants, or other sorts of irritation), lock in moisture, protect against environmental aggressors, help with inflammatory skin conditions, soften and smooth the skin, and even reduce the visible signs of aging.
But my favorite part about ceramides? They make the skin more tolerable to active ingredients that might otherwise cause irritation. This is huge for someone like me, who is still trying to reverse the damage of years of over-exfoliating.
Who Should Use It: Anyone with dry or dull skin; I’d really say anyone who isn’t super oily.
How Often Can You Use It: Ceramides are safe for frequent use, though it’s generally recommended to be applied twice daily.
Don’t Use With:
Cetearyl Alcohol:
Type of Ingredient: Emulsifier
Main Benefits/Side Effects: Cetearyl alcohol isn’t used for its effects on the skin so much as it’s used for its effects on the composition and function of a product. Cetearyl alcohol prevents the separation of products, which in turn encourages more even application and increased effectiveness. It also thickens formulas to enhance texture and feel. And, though it’s not primarily included in a product for this reason, it does soften and smooth the skin.
Cetearyl alcohol is confusing, because it’s often found in “alcohol-free” products. While, yes, it is an alcohol by definition, cetearyl alcohol is not the same as traditional, drying, sensitizing alcohols. It’s actually pretty safe.
Who Should Use It: While there’s a slight chance for irritation (like any ingredient), cetearyl alcohol is generally safe for all people.
How Often Can You Use It: Daily.
Don’t Use With: N/A, but it could be comedogenic when used in conjunction with ceteareth-20.
Charcoal:
Type of Ingredient: Absorbent
Main Benefits/Side Effects: I was actually shocked to learn that there are technically no proven benefits of charcoal in skincare. But it’s important to know what that really means. This doesn’t mean that there are no skincare benefits from charcoal; rather, any claims currently lack the science and research to back them up. Most charcoal products are promoted for acne-prone skin, which does make sense given the claims that charcoal helps remove toxins.
Who Should Use It: Because charcoal theoretically helps remove excess oil, it’d be most beneficial to those with oily skin.
How Often Can You Use It: There isn’t enough research to say. I’d go with one to three times a week.
Don’t Use With: N/A
Cocoa Butter:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: Cocoa butter is jam-packed with fatty acids and antioxidants, meaning it’s über-moisturizing and anti-inflammatory. It also protects skin from free radical damage, reduces stretch marks and scars, and heals sensitive skin.
But caution should be exercised if you’re acne prone, since this can seriously clog pores.
Who Should Use It: Anyone, unless you're acne-prone.
How Often Can You Use It: Pretty much whenever you’d like.
Don’t Use With: Other potentially pore-clogging ingredients.
Collagen:
Type of Ingredient: Protein
Main Benefits/Side Effects: Everyone and their mother is obsessed with collagen powder, pills, and the like, which I kind of think is one big eye roll. News flash: putting collagen into your skin is not going to stimulate other collagen. Oral forms of collagen have wide-reaching claims ranging from skin elasticity to improved wrinkles and glowing skin. Studies are limited, and it isn’t FDA-regulated, but as long as you do your research and feel like you’re getting at least some sort of benefit from it, go for it.
That being said, when applied topically, collagen has some serious moisturizing benefits, which make skin softer, smoother, and plumper.
Who Should Use It: Anyone interested in moisturizing and anti-aging products can benefit from collagen in skincare.
How Often Can You Use It: Both topical and oral collagen can be used on a daily basis, at any time of day.
Don’t Use With: N/A
Dimethicone:
Type of Ingredient: Emollient
Main Benefits/Side Effects: Dimethicone is a synthetic polymer of silicon (no shame, I fully had to look up what that means, it’s basically just a human-made version of a natural element on Earth). Dimethicones (like all silicones) are mainly used in skincare products for sensory reasons. They provide a silky smooth finish and allow products to have a quick-spreading, non-greasy texture.
Dimethicone is occlusive, which means it seals in hydration and keeps out external moisture and irritants. By doing this, it helps to control the shine of an oily complexion and helps to protect the skin from outside irritants. Despite this, it is technically non-comedogenic and non-acnegenic, thanks in part to its lighter, less greasy finish.
Who Should Use It: Anyone, especially those who want to prevent rough, dry skin.
How Often Can You Use It: Whenever.
Don’t Use With: N/A
Ferulic Acid:
Type of Ingredient: Antioxidant
Main Benefits/Side Effects: Ferulic acid is an antioxidant, so it works to stop aall the damage that comes from extrinsic aging. It also reduces dark spots, boosts the effects of vitamin C and vitamin E (see below), decreases redness, reduces the formation of brown spots, reduces the potential for sagging skin, and reduces inflammation. So, it’s a lot.
However, it can be irritating or acne-inducing for certain users, so do your research and spot-test before using.
Who Should Use It: Really anyone can benefit from ferulic acid, but especially those interested in an anti-aging.
How Often Can You Use It: Once daily.
Don’t Use With: Exfoliating acids like glycolic, lactic, and salicylic acids.
Glycerin:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: Derived from plants, glycerin is used in a lot of pharmaceutical creams, mostly because of how moisturizing it is. It also helps keep skin soft, supple, and hydrated, which helps protect against harsh products.
Glycerin supports the skin barrier and prevents loss of moisture by covering the outside of the skin rather than penetrating the skin barrier like most ingredients. There are no known side effects of glycerin when used in skincare, but it can be quite irritating if used in its full concentration.
Who Should Use It: It’s generally safe for all skin types.
How Often Can You Use It: Multiple times a day, every day.
Don’t Use With: There are no known interactions, but be sure not to use an 100-percent concentration.
Green Tea:
Type of Ingredient: Antioxidant
Main Benefits/Side Effects: Green tea is another favorite ingredient for me. It protects the skin against free radicals, minimizes the signs of aging, reduces excess sebum, and soothes the skin. Thanks to its anti-inflammatory and antibacterial properties, green tea is a great ingredient for those suffering from acne.
Because it’s both protective and corrective, green tea is available in a very wide range of formulations.
Who Should Use It: Almost all skin types, unless you have a known hypersensitivity to it.
How Often Can You Use It: Green tea can be both consumed and topically applied daily.
Don’t Use With: N/A
Hyaluronic Acid:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: The beauty industry loves hyaluronic acid, mainly because of its ability to retain moisture so well, which leads to hydrated, plump skin. But the fun doesn’t stop there. It also reduces the appearance of wrinkles and is fast absorbing and non-irritating.
There aren’t any known side effects of hyaluronic acid, mainly because it’s a molecule that can be naturally found in the body already. And, here’s a fun fact: one gram of hyaluronic acid can hold up to six liters of water.
Who Should Use It: Literally everyone!
How Often Can You Use It: Hyaluronic acid can be applied topically twice a day; ingestible and/or injected hyaluronic acid should be administered by a doctor.
Don’t Use With: N/A
Hydrocortisone:
Type of Ingredient: Anti-inflammatory
Main Benefits/Side Effects: There are few things more magical to me than cortisone injections. Dermatologists often use them to quickly calm and heal large, angry pimples. It just works so damn well. But I can’t go to the derm every single time I get a pimple. That’s where hydrocortisone comes in.
It’s important to first note that hydrocortisone isn’t meant for blackheads or whiteheads but rather for red, deep pimples. It’s best used as a spot treatment to reduce redness and inflammation and works particularly well with benzoyl peroxide, salicylic acid, sulfur, and retinoids (obviously not all at once, though). A lot of over-the-counter hydrocortisone products are marketed as anti-itch creams but also work effectively as spot treatments.
Who Should Use It: Anyone looking to target specific breakouts rather than an entire area of the face.
How Often Can You Use It: Hydrocortisone can be used up to twice daily for no more than two weeks.
Don’t Use With: Other hydrocortisone products or on cortisone injection sites.
Isopropyl Myristate:
Type of Ingredient: Emollient
Main Benefits/Side Effects: Isopropyl myristate is the synthetic oil version of that girl who’s always a bridesmaid, never the bride. It’s not necessarily a skincare star that you’ll find touted as a main ingredient, but it is used in a wide array of beauty products, mainly because of its formulation and skin benefits.
The hard-to-pronounce ingredient thickens formulas and helps create that desirable silky texture. As an emollient, it softens the skin and strengthens the skin barrier. And, while scientists still aren’t sure exactly how, isopropyl myristate actually changes the structure of the most external layer of skin, making it easier for active ingredients to absorb and increases efficacy.
One caveat: isopropyl myristate can clog pores, so those with acne or who are prone to breakouts should try to steer clear.
Who Should Use It: People with normal to dry skin looking for moisturization benefits will benefit most from isopropyl myristate.
How Often Can You Use It: For this ingredient, I’d suggest following product instructions, though daily or twice daily use should be fine.
Don’t Use With: It doesn’t necessarily react badly with any ingredients itself but because isopropyl myristate enhances penetration, it’s important to assess the other ingredients you’re using and whether this increased penetration might cause unexpected issues like irritation.
Jojoba Oil:
Type of Ingredient: Emollient
Main Benefits/Side Effects: As is the case with all emollients, jojoba oil helps soften and smooth complexion via hydration maintenance. Actually, jojoba oil acts so similarly to our skin’s oil that it helps balance those levels out, making it particularly useful for those with either super oil or super dry skin. It’s also rich in vitamin E, a potent antioxidant that fights against oxidative damage and signs of aging.
Jojoba oil also reduces redness and inflammation, which is especially helpful to those with sensitive complexions and acne-prone skin. It’s also non-comedogenic, which is a must for anyone with acne-prone skin. There aren’t really any drawbacks to jojoba oil, as it’s generally well-tolerated and has a low risk of irritation. You can even use 100-percent concentrations, which is fairly rare.
Who Should Use It: Suitable for all skin types, but especially beneficial for those with dry skin or those prone to acne or redness.
How Often Can You Use It: It’s safe to use daily—even multiple times a day.
Don’t Use With: N/A
Kojic Acid:
Type of Ingredient: Brightener
Main Benefits/Side Effects: While other acids dissolve the bonds between cells to exfoliate the skin, kojic acid works by inhibiting pigment production, which ultimately helps lighten and prevent hyperpigmentation. It’s also an antioxidant, meaning that it protects skin against free radicals, and has anti-inflammatory and anti-viral properties (though they’re definitely secondary to its skin-lightening benefits).
Kojic acid is less likely to cause an overly-white appearance of the skin than other traditional brighteners, making it a good option for people with darker complexions. And, while kojic acid tends to be better tolerated than most acids, it can still cause potential irritation.
Who Should Use It: Kojic Acid is great for anyone dealing with discoloration and hyperpigmentation.
How Often Can You Use It: It depends on what else you’re using and the kojic acid concentration, but it can generally be used once a day.
Don’t Use With: While it does work well with other brightening/exfoliating ingredients, it also increases the likelihood of excessive dryness and/or irritation. Tread lightly when mixing kojic acid with other actives.
Lactic Acid:
Type of Ingredient: Acid/chemical exfoliant
Main Benefits/Side Effects: God damn, I love me some lactic acid. Yes, it’s technically sour milk, but it’s so effective that I truly could not care less. The most important benefits (in my opinion) are its bacteria-killing and acne-reducing properties, which help keep my skin at bay. Lactic acid also increases cell turnover, diminishes wrinkles, and helps skin hold moisture.
The lactic acid molecule is actually fairly large, meaning it can’t penetrate as deeply as other acids. This might sound like a down-side, but it actually makes the product far more tolerable and less likely to disrupt the skin barrier (which is bad).
Who Should Use It: Anyone with acne-prone skin (me).
How Often Can You Use It: So, you can technically use it once a day at maximum, but I’d highly suggest using it two to three days a week. As someone who’s tried both frequencies, the latter is definitely less irritating.
Don’t Use With: Other acids and exfoliants (AHA's, benzoyl peroxide, etc.) and retinol.
Lanolin:
Type of Ingredient: Emollient
Main Benefits/Side Effects: Lanolin has historically been used as a nipple ointment for sore nursing mothers and as an ingredient in both diaper rash creams for babies and lip balms. So when we talk lanolin, think dry, tight, cracked skin. It’s incredibly healing and lightweight, and it can retain up to twice its weight in water.
It is wool-derived, so those allergic to wool should steer clear. Also, since it is so occlusive, lanolin should be avoided if you have congested pores or problematic skin.
Who Should Use It: Those with dry, damaged skin.
How Often Can You Use It: As often as you want!
Don’t Use With: N/A
Malic Acid:
Type of Ingredient: Acid/chemical exfoliant
Main Benefits/Side Effects: Malic acid is perhaps the most gentle AHA thanks to its large molecule size (which is even larger than lactic acid’s). So, like other AHAs, it exfoliates the top, superficial layer of skin, which helps smooth texture, fade discoloration, and unclog pores.
The real magic of malic acid, however, is its hydrating effect. It effectively attracts and retains moisture in the skin, creating a plump, dewy complexion. It also helps balance skin pH. It’s important to note that while it is a quite gentle acid, it’s still an acid, so irritation is always a possibility.
Who Should Use It: Malic acid is ideal for anyone looking to fade discoloration and/or achieve more radiant skin. It’s also great for those with sensitive or acne-prone skin.
How Often Can You Use It: Depending on what other ingredients it’s combined with, malic acid can be used daily.
Don’t Use With: Be extra cautious when using with other acids or harsh ingredients like retinoids.
Mandelic Acid:
Type of Ingredient: Acid/chemical exfoliant
Main Benefits/Side Effects: It’s a good thing mandelic acid sounds just like malic acid because they’re same same but different. Both are on the milder side of the AHA spectrum, making them ideal for sensitive skin. Mandelic acid exfoliates the skin, promoting cell turnover, brightening complexion, clearing pores, and reducing hyperpigmentation.
Mandelic acid is particularly great for sensitive, acneic skin thanks to its ability to clear deep within the pores. Again, as with any AHA, there’s potential for irritation, but that potential is quite small.
Who Should Use It: People with sensitive or acne-prone skin who are looking for a less harsh AHA.
How Often Can You Use It: I’d suggest using mandelic acid a maximum of two to three times a week.
Don’t Use With: Avoid other AHAs, peels, retinol, and retinoids.
Manuka Honey:
Type of Ingredient: Antibacterial/anti-viral/anti-inflammatory/humectant
Main Benefits/Side Effects: Manuka honey is a star in the honey community (I assume). This particular type of honey addresses a variety of skin concerns—it promotes wound healing, offers antioxidant-like protection, draws and retains moisture to the skin, and possesses strong antibacterial properties.
Given its antimicrobial content, manuka honey has a long history of being used to treat wounds, burns, and legions, though it’s only recently gained popularity in the skincare industry.
Who Should Use It: Anyone looking to hydrate and soothe skin, especially those with eczema and/or acne, will benefit from manuka honey.
How Often Can You Use It: Once or twice a day.
Don’t Use With: N/A
Marula Oil:
Type of Ingredient: Emollient
Main Benefits/Side Effects: Marula oil is a great hydrator and really seals moisture in the skin, but unlike most other oils, the benefits don’t stop there.
Marula oil is non-comedogenic and anti-inflammatory, making it a great option for those with acne-prone skin. It also has anti-aging benefits via its antioxidants, which help protect from free radicals and inhibit enzymes that break down collagen and elastin. And, perhaps best of all, marula oil has a very low risk of any type of side effect.
Who Should Use It: Marula oil works for all skin types, though it’s an especially good choice for those with dry and/or cracked skin.
How Often Can You Use It: Daily.
Don’t Use With: N/A
Methylparaben:
Type of Ingredient: Preservative
Main Benefits/Side Effects: Though not as popular as, say, hyaluronic acid or vitamin C, Methylparaben is one of the most popular ingredients in beauty products. It’s a paraben, meaning it’s used to preserve formulas and is not directly beneficial to skin health. That being said, it does help your products themselves, by preventing fungus growth and preserving ingredients.
While it is antibacterial, methylparaben can also potentially contribute to skin sensitivities and breakouts—though there isn’t a ton of scientific evidence to back this up currently.
Who Should Use It: Generally recommended for all skin types except sensitive or eczema-prone skin.
How Often Can You Use It: Multiple times a day (it’s found in many daytime and nighttime products).
Don’t Use With: N/A
Mineral Oil:
Type of Ingredient: Moisturizer
Main Benefits/Side Effects: Mineral oil is a bit of a controversial ingredient because it’s a derivative of petrolatum, though it does not contain the contaminants that unrefined petroleum is known for. Still, a lot of “clean” brands will avoid the ingredient. That being said, mineral oil can be found in most healing and moisturizing products, like Vaseline, Aquaphor, and baby oil. It’s largely occlusive, meaning it seals moisture into the skin, and, like any oil, it smooths and softens rough skin.
While the acne-prone are generally told to avoid mineral oil, we don’t really have any scientific confirmation of its comedogenicity. I say proceed with caution.
Who Should Use It: I’d recommend mineral oil to those with dry and/or sensitive skin but not to anyone with acne-prone skin.
How Often Can You Use It: This depends on the specific product being used and how dry your skin is, but it can generally be used once or twice a day.
Don’t Use With: Pore-clogging ingredients.
Niacinamide (Vitamin B3)
Type of Ingredient: Brightener
Main Benefits/Side Effects: Niacinamide is another Dani-approved ingredient. It’s particularly adept at fighting premature signs or aging and repairing a damaged skin barrier. It reduces redness and dark spots, preserves hydration, and deeply moisturizes and brightens skin.
When used in high concentrations, niacinamide can be potentially irritating. So, I suggest looking for products with low concentrations (1-2-percent) of niacinamide.
Who Should Use It: Niacinamide is ideal for anyone who wants to brighten skin or prevent the signs of aging.
How Often Can You Use It: Twice a day, every day.
Don’t Use With: N/A
Polyhydroxy Acid (PHA):
Type of Ingredient: Acid/chemical exfoliant
Main Benefits/Side Effects: PHAs are actually part of the AHA family—they are much larger in size compared to more common AHAs like glycolic and lactic. Their larger structure means that PHAs are less sensitizing and gentler than most other chemical exfoliants. Still, they share similar properties to other AHAs in that they all exfoliate the skin, smoothing texture, reducing acne, and lightening dark spots.
Unlike other AHAs, PHAs are generally non-irritating and anti-inflammatory, with tons of antioxidant properties. They also keep skin moist and fight glycation, a process that weakens collagen and elastin in the skin. Basically, the whole point of PHAs is that there are virtually no side effects.
Who Should Use It: Generally safe for all skin types, but especially beneficial for those with oily and/or acne-prone skin.
How Often Can You Use It: I’d say use it no more than three times a week.
Don’t Use With: Other acids in very high concentrations.
Phenoxyethanol:
Type of Ingredient: Preservative
Main Benefits/Side Effects: Like other preservatives, phenoxyethanol is not used for its effects on the skin so much as its effects on formulas themselves. Phenoxyethanol prevents bacteria contamination and helps stabilizes products since it doesn’t react with other ingredients, light, or air. It’s a widely used ingredient thanks to its ability to effectively fight off pathogens in a variety of products. It also prolongs product shelf life.
Who Should Use It: Everyone, unless you have sensitive skin or eczema.
How Often Can You Use It: Daily.
Don’t Use With: N/A
Polypeptides:
Type of Ingredient: Protein
Main Benefits/Side Effects: Peptides tell your cells to produce more collagen (which we want!). So topical application of peptides tells your body it needs to make more collagen, which I find really cool for some reason.
That being said, it makes sense that the benefits of polypeptides are really just the benefits of collagen—reducing the appearance of fine lines, strengthening the skin barrier, firming skin, and locking in hydration. Antioxidants found in peptides also help calm and soothe the skin, leading to less inflammation and an overall smoother complexion.
Who Should Use It: Generally safe for everyone!
How Often Can You Use It: Twice a day, every day.
Don’t Use With: AHAs reduce the efficiency of polypeptides.
Retin-A (Tretinoin):
Type of Ingredient: Chemical exfoliant
Main Benefits/Side Effects: Retin-A is was the first (and therefore most famous) Vitamin A derivative used for anti-aging. Retin-A has proven to be more effective on fine lines and wrinkles than retinol, though otherwise the two are fairly similar. Packed with antioxidants, Retin-A increases cell turnover and soothes irritation in the skin.
Here’s the thing: Retin-A also has some serious side effects. It makes skin more susceptible to sun damage, meaning you've got to be very careful with your sun exposure. Also, it can initially cause redness, peeling, and flaking—which causes a lot of people to give up after just a few weeks of using Retin-A because they’re alarmed by the initial effects. That’s why it’s important to start very slowly and work your way up to more frequent use. Retin-A can also potentially cause long-lasting dryness.
Who Should Use It: Anyone who wants to prevent acne and/or wrinkles. Retin-A is not safe for pregnant women.
How Often Can You Use It: Once a day at the absolute most. I’d suggest starting at three times a week and building up to every other day.
Don’t Use With: Vitamin C, physical and/or chemical exfoliants, and other retinol formulas.
Retinol:
Type of Ingredient: Chemical exfoliant
Main Benefits/Side Effects: Much like Retin-A, retinol is derived from vitamin A. In this case, retinol is the term used for over-the-counter vitamin A derivatives. Retinol is intense. It has anti-aging, anti-inflammatory, antioxidant, and anti-microbial properties. It also enhances anti-acne properties, if that wasn’t enough to sell you. Retinol works over time by retexturizing and resurfacing the skin, lessening visible wrinkles, lines, hyperpigmentation, large pores, and scarring.
Sounds great, right? But it’s a double-edged sword. First of all, retinol takes about two months to show visible improvements in the skin, and that two-month adjustment period is not pretty. Think thin, fragile skin with increased sensitivity that leads to peeling, flaking, and purging. Spooky. In fact, a lot of the people in the K-beauty community advise against retinol completely.
So, there are two reigning perspectives on retinol: those who trust the process and struggle through the initial adjustment period for a serious payoff; and those who believe that products should keep your skin happy from day one. I’m still not sure where I land myself.
Who Should Use It: Ideal for people with acne and/or people who want to prevent and reduce wrinkles. It’s not recommended for people with sensitive skin.
How Often Can You Use It: Typically once every few days, I’d say between three times a week to every other day.
Don’t Use With: Vitamin C, astringents, other exfoliants.
Rosehip Oil:
Type of Ingredient: Emollient
Main Benefits/Side Effects: Rosehip oil has been used since ancient times, during which it was lauded for its many healing properties. While it boasts a long list of benefits (more in a moment), its first and foremost a great emollient, deeply moisturizing and hydrating the skin.
Let’s talk benefits. Beyond moisturizing and hydrating, rosehip oil also regenerates and heals the skin, increases collagen production and skin elasticity, helps brighten and even out skin tone, fights against free radicals, calms inflammation, and combats acne. Did I mention it has literally zero known side effects?! Everyone should use rosehip oil.
Who Should Use It: Everyone!
How Often Can You Use It: All day, every day, baby.
Don’t Use With: Be cautious when using products with retinoids (Retin-A and/or retinol), since rosehip oil is high in vitamin A.
Shea Butter:
Type of Ingredient: Hydrator
Main Benefits/Side Effects: Shea butter is great for hydration and calming the skin—it even helps fade scars (both from acne and non-acne related causes). It has anti-aging properties that help plump the skin, reduce fine lines and wrinkles, and protect against free radicals.
While shea butter is technically non-comedogenic, some people with acne-prone find that it can clog pores. I’d suggest a patch test if you’re acne-prone and interested in shea butter.
Who Should Use It: Anyone with dry skin. It should be avoided by those with allergies to tree nuts and/or acne-prone skin.
How Often Can You Use It: As much as you want.
Don’t Use With: N/A
Snail Mucin:
Type of Ingredient: Moisturizer
Main Benefits/Side Effects: Weirdly enough, snail mucin is one of the first ingredients that got me really hooked on skincare. It just seemed so weird, and I wanted to know more. It’s a popular ingredient in K-beauty products thanks to its noticeable benefits on the skin. Snail mucin is largely used to moisturize the skin, though it also soothes irritation and stimulates collagen production, making it a fairly powerful anti-ager. It also delivers a ton of good-for-the-skin nutrients upon application, making it an adept multi-tasker.
Because research on snail mucin is still somewhat limited, there aren’t any well-documented side effects at this point.
Who Should Use It: Anyone can benefit from snail mucin, but it’s an especially good choice for people with dry skin.
How Often Can You Use It: Once or twice a day.
Don’t Use With: Research is limited, so we can’t conclusively say whether or not it interacts poorly with any other ingredients.
Sodium Hyaluronate:
Type of Ingredient: Humectant.
Main Benefits/Side Effects: Since sodium hyaluronate is derived from the beloved hyaluronic acid, it can hold up to 1,000 times its own weight in water. Unlike hyaluronic acid, sodium hyaluronate can penetrate deeper within the skin. It’s also more stable in cosmetic formulations, meaning it will last longer. Its hydrating benefits stretch far and wide, addressing a number of skin concerns caused by dehydration.
Sodium hyaluronate combats dry skin, repairs compromised moisture barriers, improves signs of aging (since we lose moisture within in the skin as we age), improves breakout-prone skin (if you’re overly drying it with harsh exfoliants, which a lot of people do), plumps the skin, and helps heal the skin. People also praise the non-greasy glow it leaves post-application. And it has no known side effects, though spot testing is always a good idea. An important disclaimer: if you live in a very dry environment, there might not be enough moisture in the air to pull into the skin, which could render the ingredient ineffective.
Who Should Use It: Anyone, but especially those with dry, dehydrated skin.
How Often Can You Use It: Concentrations of up to 2-percent are safe to use twice daily.
Don’t Use With: N/A
Sulfates:
Type of Ingredient: Surfectant
Main Benefits/Side Effects: Sulfates have suffered a wide-spread smear campaign that’s sullied its name. Despite this, most of the horror stories we hear about sulfates (especially in haircare products) are just that: stories, not science. Technically, sulfates are molecules that attract both water and oil, which, when used in various soaps, separate dirt and oil from the skin and/or hair. That dirt and oil is then carried off with water when you rinse, leaving you squeaky clean. While they’re not dangerous, it’s important to note that sulfate-free products are generally gentler than those with sulfates.
I want to say it again: there is absolutely no evidence that sulfates cause cancer or any other health problems when used as directed. That being said, they can potentially be irritating and drying, because they are so good at removing dirt that they have the possibility of stripping the skin and/or hair of natural oils. Sulfates can also cause premature fading of hair color and keratin services. Just be sure to ask your hairdresser if you should be avoiding sulfates or not.
Who Should Use It: Most people. People with sensitive skin and/or with colored/treated hair should probably avoid it to be safe.
How Often Can You Use It: All the time.
Don’t Use With: N/A.
Vitamin C:
Type of Ingredient: Antioxidant
Main Benefits/Side Effects: Bitches love vitamin C thanks to its well-loved benefits. Vitamin C fights free radicals, brightens/lightens hyperpigmentation, stimulates collagen production, reverses oxidative damage, and diminishes the appearance of fine lines and wrinkles. In general, it’s one hell of an anti-ager.
However, like most good things, high concentrations of vitamin C can be quite irritating to the skin. Also, vitamin C is highly reactive and can easily lose antioxidant properties when exposed to head, light, air, and other chemicals. So it’s important to prevent vitamin C products from oxidizing. Look for products in air-tight, opaque packages, and be sure to store them in cool, dark places. A key indicator of oxidization is a change in color (often to brown). If this occurs, I’d suggest tossing it and getting a new bottle.
Who Should Use It: Most people, just be careful if you have extremely sensitive and/or oily skin.
How Often Can You Use It: Daily! Or every other day if you find it’s a bit strong.
Don’t Use With: Benzoyl peroxide, other acids, and retinol.
Vitamin E:
Type of Ingredient: Barrier booster
Main Benefits/Side Effects: Vitamin E is all about hydrating and healing the skin. It protects the lipid barrier (we’ll discuss this another time), allows for long-lasting moisture retention, accelerates skin damage healing by up to 50-percent, soothes the skin, and helps protects from the sun (though it is not a replacement for sunscreen). It’s also an antioxidant, which we now know means it protects against free radicals.
Vitamin E is also known for its potential to cause dermatitis-like reactions (which is just a blanket term for any inflammation of the skin). It can also clog pores, which is especially problematic for those with acne-prone skin.
Who Should Use It: Anyone with dry skin. Those with sensitive skin should avoid.
How Often Can You Use It: Once a day, preferably at night, since it’s pretty thick.
Don’t Use With: Retinol/Vitamin A.
