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Before I was old enough to know what aging meant, adults were quick to tell me, “Beauty may fade but respect lasts forever.” (Or diamonds, depending on the adult.) Now, nearing the age of 30, I can say that’s a load of… perspective masquerading as fact.

Beauty is an opinion, just as respect depends on whom you want it from, and neither of those values have to be independent from aging — but the option to be should be respected. How I look shouldn’t dictate whether or not I feel beautiful or heard.

And yet this reality can be difficult to hold in a digital era of attention-seeking. So, let’s bring beauty back to the basics: what brings pleasure and when it comes to skin, I find pleasure in knowing exactly what I’m actually putting on my face — and why.

We partnered with Michelle Wong of LabMuffin to create an A to Z list of skin care ingredients that does your skin good, with a load of science to back it up. — Christal Yuen, Senior Editor

For several of the ingredients, we also included product recommendations based on reviews, our experience, and whether or not we’d repurchase. Keep in mind you don’t need everything on this list. Sometimes just one serum can really do it all. Or maybe ~ the ingredient is not the problem ~!

Also a beloved houseplant, aloe vera gel comes exactly from where it sounds like it should: from the sticky, clear flesh inside the plant leaves. You can grow your own aloe for DIY treatments, but test before going all-in on your skin. Natural, unfiltered aloe may induce allergic reactions in some.

Your skin’s gonna love this: Got a burn? Put aloe vera gel on it. This is a common home remedy for soothing burns and healing wounds (although the evidence for its effectiveness is not that strong). There are other potential benefits: Keeping your skin plump and moisturized, with its anti-inflammatory, antioxidant, and antimicrobial compounds (including vitamins).

While aloe can help your skin hold onto water, it can also dry out your skin too. It’s best to layer a moisturizing balm over 100 percent aloe.

Where to find it: Most sunburn treatments, moisturizers, and serums will list aloe as a gel or extract, but how much aloe per product varies.

Benzoyl peroxide is one of the most common acne treatments you’ll find. You probably used it as a teenager without knowing why the product’s promise came true. One overlooked side effect besides (a very small chance of) potential allergies? It can bleach dyed fabrics, like pillowcases and towels.

Your acne is gonna love this: Goodbye acne-causing bacteria (aka Propionibacterium acnes). This ingredient zaps those microbes on contact, and unlike antibiotics, it won’t cause microbial resistance. In the right amounts, it can also act as a mild anti-inflammatory agent to calm your skin.

And in this case, less is more. Research shows that concentrations of 2.5 percent are just as effective at busting acne as products containing 10 percent benzoyl peroxide, with less side effects (dryness, irritation, and red, flaky skin).

Where to find it: Benzoyl peroxide is found in over the counter (OTC) creams and cleansers, at concentrations between 0.5 and 10 percent. You can use it, preventatively, all over your face, or as a spot treatment on pimples. Benzoyl Peroxide 2.5%

Get it via Amazon ($24)

Vitamin C is a water-soluble vitamin found in citrus fruit, but don’t go putting slices on your face just yet. That’s not how you’re going to buff up your skin’s defense system against the environment because this is a case where application supersedes digestion. (And you’ll just pee out the extra vitamin C you ingest.)

Your skin’s gonna love this: As the first line of defense against the sun, your skin bears a lot of the brunt of oxidative stress. Vitamin C is like an ally in the army, helping your skin fight sun damage, wrinkles, and abnormal pigmentation. It’s able to fade existing pigmentation and brighten skin tone. You might also see a decrease in fine lines and wrinkles due to its ability to increase collagen formation.

Where to find it: Look for ascorbic acid in the ingredient list. The best follow-up ingredients in the product should be vitamin E (tocopherol) and ferulic acid, two other antioxidants that help stabilize it.

Paula’s Choice BOOST C15 Super Booster

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Or check out an alternative. Ascorbic acid is an A-lister but if a product irritates your skin or just goes bad too fast, try a derivative like:

  • magnesium ascorbyl phosphate
  • sodium ascorbyl phosphate
  • ascorbyl tetraisopalmitate
  • tetrahexyldecyl ascorbate
  • ascorbyl glucoside

Note: The benefits of these are less well-researched.

Tips on avoiding irritation

Test the pH. To work effectively, ascorbic acid products need to be at a low pH, so try to avoid combining it with other strong ingredients like retinoids and exfoliating acids.

Get a low percentage or dilute with moisturizer. It only takes 10 percent vitamin C to get your skin’s barrier armed against the sun, and this protective effect can last up to 24 hours.

Can’t say goodbye to suds? Opt for a gentle surfactant like decyl glucoside. Surfactants are chemicals that contain hydrophilic (water loving) and lipophilic (oil loving) portions joined together, so they can help substances like oil and dirt dissolve and wash away in water.

An ideal for suds lovers: Thanks to its a relatively large structure, decyl glucoside doesn’t enter the skin as quick, and can be rinsed off the skin easily. It also foams satisfyingly well but without the harshness that you might encounter in standard dish soap. Oh, and it’s also biodegradable, with a low environmental impact.

You probably heard how surfactants are commonly irritating to skin, but decyl glucoside isn’t the same as the infamous sodium lauryl sulfate (SLS), which causes prolonged irritation and dryness. Instead, it’s actually replacing SLS in many beauty products so folks like us can still get our foam on.

Where to find it: See a cleanser that claims to foam and be gentle? Take a look at the back and see if it contains decyl glucoside.

Krave Beauty Matcha Hemp Hydrating Cleanser

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In food, vitamin E is found in vegetable oils, nuts, and seeds. Its main role in the body is to act as a fat-soluble antioxidant, and aid in immune function and heart health as well. But like vitamin C, topical application will get you the best results with this ingredient. Especially when it comes to sun protection.

Your skin’s gonna love this: As an antioxidant, vitamin E is vitamin C’s counterpart to skin health. It protects the fatty cellular parts of your body (such as the cell membranes) from the reactive free radicals, the culprits for oxidative damage and effects of aging (often caused by UV exposure). For most people, vitamin E doesn’t tend to cause any allergic or irritant reactions.

P.S. You may see vitamin E commonly referred to as a treatment for burns and reducing scars, but there isn’t much evidence that it helps in this area.

Where to find it: In skin care, vitamin E is usually listed as tocopherol or tocopheryl acetate.

It’s frequently used in sun protection and anti-aging products at concentrations of 0.5–1 percent, due to its antioxidant effects. Brands often combine it with vitamin C or vitamin A (retinoids) to boost their action.

One study shows that when vitamins C and E were used in tandem, the combination was four times as effective at protecting against UV than either vitamin alone. The C and E pairing is even more powerful when ferulic acid is added.

Ferulic acid is found in many plants, although it’s usually extracted from wheat and maize bran for use as a cosmetic ingredient. But there’s more to this gold star ingredient.

Your skin’s gonna love this: As an antioxidant, ferulic acid can soak up reactive free radicals on your skin and prevent oxidative stress. Free radicals cause oxidative stress when reacting with other important skin components.

Hot tip: Look for it in combination with vitamin C and E. This combo is especially useful for sun protection, fading areas with excessive pigmentation, and preventing fine lines and wrinkles.

Where to find it: You’ll find ferulic acid in anti-aging products like antioxidant serums, but as we mentioned, find it combined with vitamin C and E. Ferulic acid improves their stability and together and these ingredients can neutralize more free radicals than alone.

Timeless Skin Care 20% Vitamin C Plus E Ferulic Acid Serum

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One of the most popular face acids, glycolic acid is an alpha hydroxy acid (AHA) that is more effective at a lower pH (usually pH 3–4). A word of caution with this beloved ingredient though: too much can be irritating and damage your skin barrier.

If you’re going to hop on this gly-train, do it slowly, starting at once per week before building up. And stick to the rule of absolutely wearing SPF in the day as this acid increases sun sensitivity.

Your skin is gonna love this: As a chemical exfoliant, it loosens the upper layers of dead skin cells so that they slough off more easily to reveal smoother, clearer skin. These results make it fantastic for treating aging skin. It can also:

  • clear clogged pores
  • improve skin texture and wrinkles
  • fade patches of hyperpigmentation
  • increase collagen production

Where to find it: Glycolic acid is usually found in leave-on exfoliants and toners, which you apply on skin after cleansing and before serums and moisturizers. If those products are too harsh, consider looking for a cleanser.

Pixi Glow Tonic

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Hyaluronic acid sits on top of skin and holds onto water, stopping it from evaporating, keeping your skin hydrated and plump. It’s also found deep within your skin, and its levels decrease with age.

Don’t look to hyaluronic acid to completely replace your natural stores though. It’s large molecule size won’t let it penetrate your skin deeply enough, but it will sit on top of your cheeks prettily.

Your skin is gonna drink this up: Don’t be afraid of the “acid” in the name — it doesn’t behave like other acids since its pH also matches the pH of skin. Harsh-free, baby. Topically, it can also help decrease the appearance of fine lines and wrinkles, since dehydrated skin will make them more prominent.

Where to find it: You can find hyaluronic acid in many skin care products, including serums and moisturizers, and it’s safe to use in large amounts. If you do purchase a serum that’s mostly hyaluronic acid, be sure to apply it over moist skin to maximize hydration.

Indeed Laboratories Hydraluron Moisture Booster

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Iron oxide is the skin colored pigment in cosmetic foundations. It comes in red, yellow, and brown, and these colors (in combination with white) are used to mix all shades of skin tones. We know you’re wondering why a makeup ingredient is on this guide — well, keep reading.

Your skin is gonna love this: While it isn’t usually thought of as a skin care active, it’s been found to absorb high energy visible light in the blue/violet region. The rays from this spectrum can make skin pigmentation worse, so applying foundation with this active may be a helpful extra step when you’re outside, as the sun is by far the greatest source of visible light.

Where to find it: It’ll be listed on the back as Iron oxides, CI 77489, CI 77491, CI 77492, CI 77499

Got oily skin? You might have heard people recommend jojoba oil. This ingredient is structurally close to your skin’s natural sebum, meaning its less likely to disrupt your skin’s oil production. The popularity of jojoba beads has surged recently due to increased awareness of the environmental effects of micro plastics. As a result, the beauty industry has begun to replace plastic microbeads.

Why your skin might love it: Not only are jojoba beads biodegradable, they’re also gentle on the skin due to their rounded shapes and soft texture. Win-win!

To remove visible skin flakes and brighten dull, coarsely textured skin, gently massage it over freshly cleaned skin for around 15 seconds and then rinse off with lukewarm water.

Where to find it: It’ll be labeled as “Hydrogenated jojoba oil” and if you use it, it’s best to use it on freshly cleansed skin. Keep in mind jojoba bead scrubs should only be used 1 to 3 times per week and you should only use minimal pressure when massaging.

Natio Detoxifying Face Scrub With Jojoba Beads

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Got reservations about Aztec clay? Try kaolin clay. This finely ground clay is often mixed with plant extracts and oils for additional skin care benefits, and to keep unwanted shine away.

Have oily skin? You’ll love it: The clay absorbs excess skin sebum, which can help with preventing acne and oiliness. After product use, some clay will stay left behind on the skin which stops oily shine from developing throughout the day.

In most cases, kaolin clay does not need to dry completely to be effective. If the mask is difficult to remove, it can be soaked off with a damp cloth. They should be used 1 to 2 times per week.

Where to find it: This popular ingredient is in rinse-off clay face masks, especially for oily skin. You can also buy loose powder to make DIY clay masks or look for it in makeup setting powders and lotions since it has mattifying properties.

QUEEN HELENE Masque Mint Julep

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Licorice extract comes from the root of the licorice plant (Glycyrrhiza glabra) and has a number of antioxidant and anti-inflammatory properties. It’s an especially popular ingredient in products designed for sensitive skin as other ingredients with similar benefits tend to be harsher and more irritating.

The benefits: The two components that make licorice a particularly good ingredient for fading pigment in sensitive skin are glabridin and liquirtin. These protect skin from sun-induced pigmentation, slow down the production of melanin in the skin, and makes melanin that’s already in the skin disperse and fade.

People with dark skin, who are prone to post-inflammatory hyperpigmentation, may especially like this ingredient since it’s less likely to lead to inflammation.

Where to find it: Look for ingredients that promise spot fading and check if licorice extract is on there. You may also see it combined with other ingredients, such as vitamin C, to lessen potential irritation.

Stratia Rewind

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You may have heard of mineral oil’s bad reputation — mostly because of the negative connotations of petroleum — but there’s a reason this ingredient remains up there as a very common moisturizing ingredient. It has a long history of safe use. If you’re worried about toxic byproduct, this gets filtered out in cosmetic-grade mineral oil.

Why your skin might love it: If you noticed Vaseline keeps your lips and skin soft, well mineral oil works in a similar way. As an occlusive moisturizer, it forms a film on the skin that repels water. This slows the evaporation of water from the skin, keeping it hydrated.

And since it’s highly purified and refined, it’s also less likely to cause allergic and irritant reactions compared to natural ingredients. People with sensitive skin may like applying mineral oil as the final step to keeping their skin hydrated.

It’s also widely believed that mineral oil is comedogenic. However, this perception comes from studies on rabbit ears. Later studies on humans found that mineral oil isn’t actually comedogenic.

Where to find it: Mineral oil is found in many heavier facial moisturizers. It’s the main component of baby oil and can be used as a makeup remover, or as a pure body oil.

Niacinamide is a form of vitamin B3 and is considered one of the holy grails of skin care due to its history of scientific and clinical support. Beyond making unwanted concerns go away, niacinamide also helps your skin keep its guards up, aka it assists with maintaining skin barrier function.

A healthy barrier can prevent water loss and minimize the development of crinkly and uncomfortable dehydrated skin. An improved barrier function also prevents environmental irritants from penetrating into the living layers of your skin.

Why your skin might love it: Your skin needs a friend like niacinamide! Niacinamide increases the level of ceramides (which are also good for your barrier function) in the skin, making it fantastic for moisturizing dry skin.

It also helps out with wrinkles, uneven skin tone, hyperpigmentation, and boosts antioxidant content in your skin. There’s even some evidence that niacinamide can prevent the overproduction of sebum, helping people with oily skin.

Where to find it: Niacinamide is in everything from serums to moisturizers, particularly for sensitive skin. But you might want to keep an eye out for sunscreens with it. In sunscreens, it can improve immune function and help boost cancer prevention properties.

Sun Sense Daily Face SPF50 Sun Screen

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Niacin impurities in niacinamide products can cause your skin to temporarily turn red. You won’t know until you’ve tried it, or read a review, but rest assured: while this reaction may be uncomfortable, it isn’t harmful.

You know this old school ingredient so it seems redundant to explain, but let’s confirm right here: oatmeal has stood the test of time.

The key actives, avenanthramides, only make up a small fraction (0.03 percent) of oatmeal, so if you’re looking for gold star results, you may want to look for formulated products instead of DIY recipes.

Why your skin might love it: As mentioned, avenanthramides are what give oatmeal its powerful anti-irritant and anti-inflammatory effects. This contains beneficial components that aid dry and sensitive skin, especially skin with eczema and psoriasis.

Oatmeal also contains starch, proteins, lipids, and beta glucans, which can act as skin moisturizers. And while it is definitely not a sunscreen substitute, it can provide some antioxidant and UV-protective effects on your skin.

Where to find it: Oatmeal extract is common in lots of cosmetic products. It’s also a very easy DIY ingredient. You can mix ground oatmeal into any DIY mask, or tie a few handfuls of oatmeal in an old, clean stocking and glide it over your skin in the bath to soothe irritation. You can also soak oatmeal in warm water and use the liquid as a DIY serum or essence.

Aveeno Soothing Bath Treatment

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From a chemical standpoint, peptides are chains of amino acids joined together. They can also be thought of as fragments of proteins, which means there are a range of different peptides with different activities and different levels of evidence backing them up. Most peptides in skin care have anti-aging properties.

Why your skin might love it: The big advantage in using peptides is that your body already uses them to communicate, so they’re more easily recognized.

Popular peptides in skin care include:

  • Cu-GHK (copper tripeptide): promotes the synthesis of skin components including collagen, elastin, and glycosaminoglycan, and improves wound healing. In clinical trials it’s been found to improve skin elasticity, thickness, wrinkles, and pigmentation.
  • Pal-GHK (palmitoyl tripeptide-1 or palmitoyl oligopeptide): promotes collagen and glycosaminoglycan production, which decreases the depth of wrinkles and increases skin thickness. It’s one of the components in the patented blend Matrixyl 3000, along with palmitoyl tetrapeptide-7.
  • Argireline (acetylhexapeptide-3): It improves skin tone and decreasing wrinkles. It is often marketed as an alternative to botulinum toxin, since it has a structural similarity to its substrate.

Where to find it: Most products will market their peptides on the bottles, however most peptides don’t have many studies backing their effects, and often no independent data is available.

If you do purchase peptides, keep in mind that they often degrade easily, so it’s a good idea to keep any peptide-containing products in a cool area.

More formally known as coenzyme Q10, or ubiquinone (yes we skirted the alphabet rules here), this chemical is vital for cell function. It’s naturally produced by the body during the energy production process in the mitochondria of cells. Big words, big effects.

Your coenzyme Q10 levels drop off in times of stress, dietary troubles, and with increasing age. Meaning your cells can’t produce energy as efficiently, which leads to sagging skin, loss of firmness and elasticity.

Why your skin might love it: You can drink it, eat it, or apply it. One study found that applying coenzyme Q10 on the skin improves the appearance of wrinkles. Since coenzyme Q10 is also an antioxidant, it can work to reduce pro-aging free radicals when applied on skin. If you’ve also ever been to a Japanese supermarket, you may have seen tiny coenzyme Q10 drinks. Research has found that dietary versions of this ingredient also improved wrinkles and skin smoothness.

Where to find it: Coenzyme Q10 is found in a lot of creams and serums, where it’s usually listed as ubiquinone. As well as dietary supplements, you can find coenzyme Q10 in many foods including meat, eggs, nuts, and green vegetables.

Retinol is a form of vitamin A (retinoid). It works by affecting the way skin cells (keratinocytes) grow and develop and increase how quickly dead skin cells are shed. This means retinol can reduce clogs in the skin, control the growth of acne bacteria, and decrease skin inflammation. They can also speed up pigment fading with skin cellular turnover.

Like other retinoids, retinol can be irritating to the skin at first, although the irritation will usually fade within a month of use. A very small quantity of retinol should be used in the evening at first, before building up to larger amounts. If irritation, redness, and peeling skin develops, it can be used every other day until your skin adjusts.

Why your skin might love it: Vitamin A derivatives (retinoids) are some of the most evidence-backed ingredients in skin care and are used for treating:

  • acne
  • aging
  • sun damage
  • pigmentation disorders (e.g. melasma)
  • rosacea
  • actinic keratosis
  • ichthyosis

Retinoids can also increase the production of collagen in the skin and increase epidermal thickness, which leads to plumper, smoother skin.

Where to find it: Many retinoids are prescription-only drugs, but for OTC ease, look for retinol. Retinol is one of the most powerful forms for regular skin care products and can be easily found in the beauty aisle of superstores.

NeoStrata Retinol & NAG Complex

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Salicylic acid, also known as beta hydroxy acid or BHA, is a skin care ingredient derived from the bark of the willow tree. The ingredient is unusual in that it’s more oil-soluble than other chemical exfoliants, making it better able to penetrate pores. It’s also one of the most common chemical exfoliants you’ll find in skin care, and another one you may have unknowingly used in your teens.

Why your skin might love it: Got clogged pores in the form of blackheads and acne? Swipe a product with salicylic acid (SA) over it.

SA is capable of loosening the top layers of your skin so they’ll slough off more easily, leaving behind brighter, smoother skin. It’s also anti-inflammatory, so it can calm down angry skin without leaving a trail of red.

Where to find it: You can find cleansers, toners, and serums containing salicylic acid, usually at 0.5–2 percent concentration. It can be found in both rinse off and leave on formulas.

Kate Somerville ExfoliKate Intensive Exfoliating Treatment

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Aspirin allergy?

Note that while it’s structurally related to aspirin (acetylsalicylic acid), they are not the same, so you can’t get the same effects as salicylic acid from crushed aspirin tablets, or vice versa! However, if you’re allergic to aspirin, it’s best to avoid this ingredient.

Tea tree oil comes from the leaves of the Australian tea tree (Melaleuca alternifolia). It has a strong menthol-like odor and antibacterial and antifungal properties.

The most economical option is to dilute pure tea tree oil with 19 portions of a carrier oil, like sunflower or mineral oil, as this ingredient is potent and irritating at high concentrations. (So, that’s 1 drop tea tree for every 19 drops carrier.)

Your acne is gonna love it: In skin care, tea tree oil is primarily used to target acne as it has the ability to kill Propionibacterium acnes, the main species of acne-causing bacteria.

If you don’t like benzoyl peroxide, try tea tree oil, which is less irritating. Research has found that 5 percent tea tree oil is as effective in reducing acne lesions as 5 percent benzoyl peroxide, although it acted a bit slower.

Where to find it: Tea tree oil can be found in lots of products that target acne-prone skin, like cleansers, serums, and spot treatments. When diluted, the mixture can be used all over the face, or as a spot treatment for pimples. Don’t try to use water to dilute this ingredient as it cannot be dispersed evenly without an emulsifier.

The Body Shop Tea Tree Line

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Urea is naturally found in the skin’s natural moisturizing barrier, which is also made up of amino acids and more. Your body’s availability of urea decreases with age. If you’re using retinoids or exfoliating acids on your skin and see irritation or dryness, stick to lower concentrations of urea. Due to its exfoliating properties, it might irritate your skin.

Why your skin might love it: In products, it acts as a humectant moisturizer ingredient, holding onto water and keeping the skin hydrated. It also regulates the composition of skin, and acts as an exfoliant to help remove dead skin. Need more benefits? It can also be anti-itching and antimicrobial!

Where to find it: Look for urea in moisturizers and serums. Hand creams and foot treatments commonly include high concentrations of urea to soften calloused skin, but at lower concentrations urea is also great for the face.

Urea only!

Note: Some preservatives will have the word “urea” as part of their name (e.g. diazolidinyl urea, imidazolidinyl urea), but don’t have any of the same effects as urea. Make sure you look for “urea” on its own in an ingredient list!

There are many vegetable oils that make great moisturizers for your skin. The most appealing part is how cheap and easily available they are. You might not have given it too much thought (except for coconut oil, which can be pore-clogging), but sunflower, sweet almond, rosehip seed, hemp, borage, and marula oils are all popular plant oil options.

Why your skin might love it: Many of these plant oils used in skin care contain antioxidants, which can help neutralize the damaging free radicals that lead to oxidative stress and skin aging.

No matter which plant you choose, look for cold pressed and cold-extracted oils. These are best if you want to take advantage of the antioxidant benefits of vegetable oils, since heat often decomposes antioxidants.

Where to find it: These oils can be found in all natural products but if you want them undiluted, depending on the type of oil you’re looking for, you should be able to some of them at your local grocery store (coconut and sunflower, for example). Hemp is increasingly easier to find due to the green rush of CBD content. Other oils like rosehip seed, borage, and marula can be found at health or spiritual stores.

Witch hazel comes from the leaves and bark of the Hamamelis virginiana plant. You’ve probably heard of it as a standard toner ingredient, but since witch hazel extracts are often alcohol-based, these products can be harsh and drying on skin.

Why your skin might love it: In skin care, it’s mostly used as an astringent, which temporarily tightens pores, reduces puffiness, and refines skin texture. It also has anti-inflammatory properties and can decrease skin redness, and contains antioxidants which decrease the impact of environmentally-induced oxidative stress.

Where to find it: Beyond toners, witch hazel is sometimes added to other products for oily skin, including acid exfoliants and acne treatments. You can find witch hazel in shampoos as well as to reduce scalp irritation. Try to find one free of alcohol, or one which does not have ethyl alcohol (alcohol denat) high up in the ingredients list to avoid unnecessary harshness.

Thayers Witch Hazel Toner

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Finding a well-researched ingredient that provides a noticeable skin boost and starts with the letter X? Like scraping the bottom of the barrel. So instead of having Michelle dig through her knowledge archives, I decided to push the limits and note exactly what ingredients we should X off our face.

This bit isn’t going to be about going anti-chemical (everything has a chemical structure) or all natural (as natural can also cause side effects in some people). It’s about what’s got the red flags, as researched and tested by experts, so you don’t damage your skin and internal health. — Christal

These are the top 5:

  • Lemon juice: The beneficial ingredient of lemon juice is vitamin C, citric acid, and niacin, however the exact amount of these can vary, depending on the lemon. Meaning, every time you put this acidic fruit on your face it’s a guessing game. There have also been many studies detailing how citrus juice has caused skin burns after sun exposure or uneven skin patches.
  • Formaldehyde: This tricky ingredient is often found in tiny amounts to help preserve skin care and primarily in nail hardeners. In large doses, it can be an irritant that causes asthma attacks, itchiness, and headaches. But because it’s also a known human carcinogen (cancer-causing), we recommend avoiding it completely.
  • Toluene: Common in nail polish, toluene is what keeps nail polish smooth and chunk-free. It’s also an unfriendly ingredient for the senses as it can depress your nervous system and, with overexposure, may damage your lungs, liver, and kidneys.
  • Glitter: It’s a great way to get that extra glow, but microplastics can be irritating for sensitive skin. Plus, its not so great for the environment. The best way to glow is to have a solid skincare routine.
  • Triclosan: In 2016, the FDA stopped recognizing antibacterial soaps and body washes as “generally safe and effective,” citing that triclosan and triclocarban haven’t been proven to be “safe for daily use over a long period of time.” The good news? You can just use regular soap and water.

If it seems like there’s one too many food items on this list, that’s because, well, they work. Yogurt is inexpensive and mostly safe for direct use on skin, so we’re not complaining.

Big caveat: the quantities of probiotics in yogurt aren’t regulated so for visible progress, DIY yogurt masks may not be the greatest ingredient. That doesn’t mean its properties are completely useless though — keep reading.

Why your skin might love it: Yogurt contains lactic acid, which causes its sour flavor. Lactic acid is an exfoliating alpha hydroxy acid which can help dead skin cells shed, making skin look clearer and smoother, reduce acne, fade hyperpigmentation, and moisturize. There’s also protein and fat in yogurt, which are great for moisturizing skin.

While studies on the application of probiotics to skin are lacking, one study found that a live strain of Lactobacillus, a yogurt probiotic, reduced acne-related skin redness and restored skin barrier function when applied on skin at 5 percent.

Where to find it: You know where to look, so our only advice is to not take the yogurt from work. But if you’re seeking these skin care benefits, it’s more advisable to use properly formulated skin care products for an effective dose. However, if you’re into DIY skin care, moisturizing yogurt might be a good, cheap option.

Zinc oxide is a mineral ingredient found in sunscreens. It’s often referred to as a “physical sunscreen.” If you noticed your sunscreen leaving a white cast, it’s probably zinc!

Zinc oxide-based sunscreens tend to be thick and sticky because the particles tend to accumulate — aka there is no such thing as effective, thin zinc-based sunscreens. If you do have a lighter textured zinc sunscreen, its ability to protect against UV rays might be reduced. Unfortunately, there isn’t really a way around this problem!

Why your skin might love it: What zinc is good for though is use around the eyes and for people with sensitive skin since it’s not associated with allergic reactions.

Zinc oxide particles do a lot of heavy lifting. They work by absorbing, reflecting, and scattering UV light before it can reach the skin; and reducing the incidence of sunburn, skin cancer, and premature sun-induced aging. As a broad-spectrum ingredient, it’s also able to protect skin from both UVA and UVB rays.

Where to find it: Besides sunscreens, zinc oxide can also be found in calamine lotion and diaper rash creams as it can protect against abrasion. Mixing your own zinc oxide will not give you SPF protection, and you have to apply sunscreen according to the directions on the bottle for it work.

This usually means applying about a shot glass full for the whole body (including half a teaspoon for the face, neck, and ears), 20 minutes before going into the sun. Sunscreen should also be reapplied after going into the water, and every 2 hours. To improve protection on active days, choose a water-resistant sunscreen.

Neutrogena Sheer Zinc Face Mineral Sunscreen

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Nanoparticles alert!

Since zinc oxide is made of larger particles, they tend to reflect and scatter visible light, leaving a “white cast.” To get around this problem, zinc oxide is usually ground into extremely small nanometer-sized particles, which are more transparent.

While current evidence shows that zinc oxide nanoparticles can’t penetrate through the skin into the body, these nanoparticles are still a controversial ingredient due to health concerns.

Michelle explains the science behind beauty products on her blog, Lab Muffin Beauty Science. She has a PhD in synthetic medicinal chemistry. Follow her for science-based beauty tips on Instagram and Facebook.