Hyaluronic acid, vitamin C, retinol — you might know, love, and use these ingredients on the regular, and for good reason. They’re the key ingredients often highlighted on product labels, and some have taken over entire skin-care categories (exhibit A: vitamin C serums).

While they’re colloquially referred to as “active ingredients” — which isn’t exactly right, for reasons we’ll get into in a second — you might think of them as the results-driven ingredients that do much of the heavy lifting in skincare products, delivering their hydrating, brightening, and smoothing effects. 

Here’s a quick overview about so-called active ingredients:

  • While most people know them as the ingredients targeting a specific concern, the FDA considers them the closely regulated ingredients in over-the-counter products that deliver a given benefit, like zinc oxide in sunscreen
  • They’re found most often in serums, but have branched out to other products
  • It can be tricky to tell whether you’re getting a high enough concentration of an active for it to be effective in a given formula; at NakedPoppy, we vet every product we carry!
  • The most popular (and effective) actives include: retinol, vitamin C, alpha hydroxy acid, and hyaluronic acid

Intrigued about what ‘actives’ are doing for you? Here, we break it down.

So…what is an active ingredient?

Caution: Nuances ahead! “Generally, the term ‘active ingredients’ refers to the ingredients used in skincare products that are being used to help with a specific concern,” says NakedPoppy research scientist Marisa Plescia. These ingredients vary depending on what the product aims to do — hydrate, exfoliate, brighten — and include recognizable names like hyaluronic acid and vitamin C.

That said, the term “active ingredient” can cause some confusion when you take FDA regulations and labeling into consideration. In the FDA’s eyes, this actually refers to ingredients that are regulated in various over-the-counter products, such as sunscreens, anti-acne products, antiperspirants, and hand sanitizers, among others. “These are the ingredients that are effective on the specific OTC claim of the product and are labeled on the products as ‘active ingredients,’ while all the additional ingredients in the product are labeled as ‘inactive ingredients’,” says Plescia. 

For example, sunscreen will have an “Active Ingredients” section on the label that shows the percentage of the ingredient that, per the FDA, is approved to deliver the efficacy of the SPF — like zinc oxide at 16.0%, if you’re looking at a mineral sunscreen. That allows the products to say “helps prevent sunburn” on its packaging.

Meanwhile, “key” ingredients in products that aren’t regulated by the FDA live in the ingredient list, and you usually won’t find the monograph box sharing the percentage. (Here’s what that looks like.)

Where to find these active ingredients

Historically, these ingredients tend to appear in treatment-based products, such as face serum. “Serum formulations incorporate higher percentages in a single potent formulation,” says NakedPoppy skin specialist Tara Parenti.

But that’s no longer the case. “Product development has really evolved and we are seeing innovative formulations with unique delivery systems,” she explains. “So, many factors are taken into consideration when formulating that go way beyond the formulation itself, such as user experience and efficiency. People want easy-to-use, quick, and effective products.” For that reason, you can now find lactic acid in a cleanser formula, or a time-release retinol complex in a moisturizer. 

It can be hard to tell whether the key ingredient(s) is at a concentration shown to make it effective, however. “A general, but not always foolproof, way of determining if a skincare product has a higher concentration of an ingredient is to see where it falls on the ingredient list,” says Plescia. “Ingredients are listed in terms of descending concentration up until 1.0% — and then at 1% and below, can be listed in any order. Thus, if the ingredient is higher on the ingredient list, chances are that it is at a higher level.”

The brand matters here, too. “Some are almost ‘micro-dosing’ their percentages of key ingredients and spreading them across an entire collection of products in lower percentages, allowing for a safer and healthier way for skin to acclimate, rather than putting really, really high percentages in one single product,” says Parenti.

Psst: Here at NakedPoppy, we vet every product — and that includes looking into the ingredients in the brands we carry and, if there’s any question, checking ingredient levels with brands to confirm that you’re getting a truly effective product.

How to use active ingredients in your routine

To Parenti’s earlier point, more and more skincare brands are incorporating some of these ingredients into multiple steps of their routine. “I think the biggest mistake that people make is incorporating exfoliation in multiple steps of a routine or using high percentages in multiple steps when it’s not necessary,” she explains. 

Not sure which key ingredients are right for your skin type and concerns? We’ve got you covered with our easy, 3-minute beauty assessment, which uses an algorithm to determine your Perfect Picks.

Also worth keeping in mind: It’s not all about the key ingredients. “A complete personal care product is a sum of all of the parts for an effective, stable, and preserved formulation,” says Plescia. “Besides the key ingredients that are fitting the marketing claim of the skincare concern — such as AHAs for exfoliating properties — the formula will include a variety of additional ingredients all with a function.”

Bottom line? Having context for the key ingredients in a given formula is important!

The most popular key ingredients in skin-care

Retinol

“Retinol, considered to be the gold standard in age defiance, is an antioxidant which targets nearly every single skin concern you can think of,” says Parenti. “Retinol helps to stimulate cell turnover, synthesizes collagen production, helps to control blemishes and congestion, and fades discoloration.” Find it in Maya Chia The Straight A Serum, which uses an encapsulated version to avoid irritation.

It’s particularly powerful when it comes to photoaging. “Photoaging is caused by UV radiation such as the sun’s UVA rays,” says Plescia. “With photoaging, the skin can become coarse and can thin, leading to a loss of elasticity and wrinkles — and can also become hyperpigmented with sun spots and melasma.” But there are many, many studies that indicate that retinol can restore elasticity and stimulate collagen synthesis, making it one of the most valuable key ingredients on the shelf.

Humectants

Humectants, like hyaluronic acid and glycerin, are a no-brainer. “Humectants can absorb water from the air and help to hydrate and even plump skin,” says Plescia. Naturally found in the body, hyaluronic acid — or sodium hyaluronate, as it’s often found on ingredient lists — is part of skin’s Naturally Moisturizing Factor (or NMF), which is responsible for keeping skin hydrated and healthy. “In addition to hydrating the skin, hyaluronic acid can help reduce the appearance of wrinkles and fine lines,” says Plescia. “Dehydrated skin is a cause of wrinkles, and HA can replenish the water in the skin and ‘plump’ the skin to reduce the look of the fine lines.

While hyaluronic acid gets the spotlight these days — deservedly so — Parenti is a fan of its cousin, glycerin, as well. “It’s generally derived from plant oils or through the sugar fermentation process,” she says. “It helps to bind water to the epidermis, making the skin hydrated and plump.”

Alpha hydroxy acids

Also known as AHAs, this class of exfoliating acids dissolve the glue that binds dead skin cells together; they include glycolic, lactic, citric, mandelic, and tartaric acids. That’s kind of a big deal. “Leftover dead skin cells on the surface of the skin can leave skin dull, flakey, and dry, and can even clog pores leading to breakouts,” says Plescia. “By using acids in skincare and by removing the excess dead skin cell buildup, cell turnover and new skin cells are stimulated. Skin is renewed, smoother, healthier, and more radiant.”

While there are many types of alpha hydroxy acids, glycolic and lactic acids are two of the best known. While glycolic acid is popular in peels, “lactic acid is especially great due to its natural potent benefits for the skin and suitability for more sensitive skin,” says Plescia. “In addition to being exfoliating, lactic acid is part of the skin’s NMF — in other words, lactic acid has humectant properties and can be very hydrating when used in skincare.” A true multihyphenate: We love to see it. You can find four types of acids, including lactic, in Maya Chia’s The Refresh Mint Resurfacing Moisture Mask.

Vitamin C

Vitamin C is an MVP in skincare, and for good reason: “Vitamin C, a powerful antioxidant, is an excellent skincare ingredient with multiple benefits including boosting of collagen synthesis, mild and gentle exfoliation, powerful skin-brightening, and additional antioxidant protection,” says Plescia. “Its ability to neutralize free radical formation as an antioxidant can help the skin respond to oxidative damage from environmental aggressors, such as the sun, as well as inhibit free radical formation — which is highly connected to premature skin aging.”

But not all vitamin C is created equal; Parenti’s favorite form is textrahexyldecyl ascorbate, a lipid-soluble ester of vitamin C. “It’s highly stable and has the ability to maintain its potency due to its delivery and ability to remain in the epidermis, compared to other water soluble forms, which tend to pass through the epidermis rather quickly, causing oxidation and loss of activity,” she explains. “It’s ideal for sensitive skin, whereas water soluble forms tend to be highly acidic and can cause reactivity.”

Whichever key ingredient(s) you choose, you can rest assured knowing that it’s actually doing something real for your skin — and delivering real results. 

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