Ask an expert: What are the best skincare ingredients?

Countless skincare products are on the market, and more appear every day. So it’s no surprise that comparing active ingredients can seem confusing. After all, many are hard to recognize, let alone pronounce. Fear not! We’re here to help make sense of it all. 

The truth is the best ingredients for skincare vary from person to person according to their specific skin needs and concerns. Here we’ll explain the basics of how skincare ingredients work, tell you a bit about some of our favorites, and highlight the ones you may be best off skipping altogether.

How important is knowing your skincare ingredients?

When it comes to understanding the ingredients in skin care products, first things first: Everyone’s skin is different, and there’s no one-size-fits-all answer. That means there’s no single “best” skincare ingredient for redness from rosacea, acne, or the signs of aging, just like there isn’t one skincare product that’s the most important (well, maybe sunscreen!).

Knowing which ingredients to use starts with knowing your unique skin and skincare goals. If it seems overwhelming (and if so, you’re not alone!), seeking professional advice from a licensed dermatology provider can help determine which products to use and which to avoid.

Clear skin with powerful acne-fighting ingredients

Treating and preventing acne from occurring starts with using the right skincare active ingredients. Here at Curology, we often recommend these four well-researched ingredients, all scientifically proven to be effective at fighting acne: 

Tretinoin 

Tretinoin (Retin-A, Refissa, or Tretin-X) is considered the gold standard of acne care, and it’s also a powerful anti-aging ingredient. Derived from vitamin A, it’s the prescription-strength cousin of over-the-counter retinol. Tretinoin works by stimulating the growth of new cells and helping repair skin damage. When used to fight acne, it boosts cell turnover, aids in stabilizing the cell regeneration process, calms inflammation, reduces the appearance of dark spots, and unclogs pores.¹

Azelaic acid

Azelaic acid is a mild, naturally occurring exfoliant that helps treat and prevent clogged pores and acne-causing bacteria.² Derived from barley, wheat, and rye, azelaic acid also helps fade dark spots from post-inflammatory hyperpigmentation (PIH), which sometimes occurs once acne clears.³ As inflammation triggers an increase in melanin production (the pigment that gives skin its color),⁴ dark spots can appear where acne lesions once were.

Benzoyl peroxide 

Benzoyl peroxide is an over-the-counter topical antiseptic that targets bacteria contributing to breakouts and may soothe inflammation.⁵ This ingredient is often combined with prescription-only clindamycin, a topical antibiotic. Together, this duo can treat acne lesions such as open and closed comedones (blackheads and whiteheads), papules, and pustules. Clindamycin dives deep into the hair follicles, where bacteria live, while benzoyl peroxide sloughs away dead skin cells. 

Salicylic acid 

Salicylic acid is a beta-hydroxy acid (BHA) and chemical exfoliant used to prevent and treat blocked pores. It’s oil-soluble to penetrate deep into your skin’s pores to dissolve excess sebum (skin oil). A well-known active that’s available over the counter, it may help smooth skin texture and reduce the appearance of enlarged or visible pores.

Rejuvenate the skin with anti-aging actives

“Formulated for anti-aging” is a common buzzword in the skincare industry. But some products work better than others, and it all comes down to ingredients. Fortunately, several natural ingredients in skincare can help reverse the signs of aging, such as green tea, vitamin C, and vitamin E. CBD is another natural ingredient that may help improve chronic skin conditions. Here are some of our go-to’s for rejuvenating the skin, reducing the appearance of fine lines and wrinkles, and improving skin integrity:

• Vitamin C is a common ingredient in skincare products, and with good reason. It’s one of the most potent antioxidants for protecting against free radical damage and photoaged skin. It also boosts collagen production, improves skin integrity, and brightens skin by reducing dark spots—although you’ll need to be patient as it can take some time to notice improvements.⁶

• Niacinamide is a form of vitamin B3 that is both a powerful antioxidant and anti-inflammatory. It helps tackle fine lines, wrinkles, and dark spots, as well as repair sun-damaged skin, enhance skin elasticity, prevent transepidermal water loss (TEWL), and improve the skin barrier.⁷ This ingredient is commonly used to treat hyperpigmentation.   

• Hydroquinone is a brightening agent that prevents melanin synthesis. It’s commonly used to improve skin tone and treat PIH, melasma, solar lentigines (dark spots), and freckles. It’s a topical depigmentation agent used with sunscreen to protect against UV damage.⁸ 

• Alpha-hydroxy acids (AHAs), such as glycolic acid and lactic acid, work by removing dead skin cells to reveal the newer, healthier skin below. AHAs attract water to the skin to boost hydration and skin turgor (elasticity).⁹ 

Other ingredients worth mentioning include hyaluronic acid, ceramides, and collagen peptides. Some of these ingredients work as humectants that attract water to the skin’s surface. They’re the building blocks that give skin its structure and improve firmness.

All about “skincare cocktailing”

“Skincare cocktailing” refers to the technique of layering skincare active ingredients to tackle multiple skincare concerns, such as acne and signs of aging, simultaneously. Creating a customized skincare routine by mixing and matching different actives can help you to reach your skin goals more quickly. This doesn’t mean mixing ingredients before applying them to the skin. Instead, it’s a process of applying the different products in your routine in layers. Some great combos include: 

• Vitamin C and sunscreen with at least SPF 30 work together to boost sun protection while preventing oxidative stress caused by sun damage. 

• Retinoids and hyaluronic acid or niacinamide work deep into the dermis to treat acne and reduce signs of aging.

Another common method is skin cycling, which balances active and recovery nights to minimize irritation while reaping the benefits of active ingredients. A four-night skin cycling routine might include salicylic acid or glycolic acid on night one, followed by tretinoin on night two, followed by two recovery nights, during which no actives are applied. 

Five skincare ingredients to avoid

Not all skincare ingredients are beneficial for the skin. In fact, some may not be good at all! These five ingredients should generally be avoided for all skin types: 

• Formaldehyde is a known carcinogen, meaning it may cause cancer. Nonetheless, it’s common in cosmetics. Formaldehyde’s well-deserved bad rap has seen it slowly disappearing from skincare products, but there are still related ingredients to look out for. Formaldehyde releasers are ingredients that (you guessed it!) release formaldehyde. Bronopol, DMDM hydantoin, diazolidinyl urea, imidazolidinyl urea, and quaternion-15 are common preservatives that slowly transform into formaldehyde.¹⁰ 

• Added fragrances and dyes may be irritating, especially for dry or sensitive skin. This includes synthetic fragrances and essential oils. That said, some products with added fragrance may be fine to use! As everyone’s skin is different, we recommend sticking with what works for you. 

• Alcohol is another common cause of skin irritation. The FDA warns that products labeled “alcohol-free” may still contain denatured alcohol (abbreviated SD alcohol or alcohol denat). “Alcohol-free” FDA regulations refer to ethyl alcohol only.¹¹

• Comedogenic ingredients are pore-clogging ingredients that can lead to acne breakouts. Coconut oil is a popular skincare ingredient that is comedogenic. Here’s our cheat sheet listing pore-clogging ingredients. 

At Curology, we use clinically researched ingredients

Skincare is personal, and not every ingredient is right for every person. That’s why it’s important to seek professional advice from a licensed dermatology provider before adding new ingredients to your routine.

That’s where we come in! Curology was founded in 2014 by a board-certified dermatologist, and our licensed dermatology providers believe everyone’s skin is unique. Curology can prescribe a personalized formula with clinically researched ingredients to treat your skin’s needs, focusing on acne, anti-aging, rosacea, and hyperpigmentation.

Signing up is easy. Just answer a few questions and snap some selfies to help us get to know your skin better. If Curology is right for you, we’ll pair you with one of our in-house licensed dermatology providers.*

P.S. We did the homework so you don’t have to:

1. Baldwin, H.E., et al. 40 Years of topical tretinoin use in review.Journal of Drugs in Dermatology. (June 2013).

2. Zaenglein, Andrea L., et al. Guidelines of care for the management of acne vulgaris.Journal of the American Academy of Dermatology. (2016, February 17).

3. Hollinger JC, et al. Are Natural Ingredients Effective in the Management of Hyperpigmentation? A Systematic Review. J Clin Aesthet Dermatol. (February 2018).

4. Silpa-archa, Narumol, et al. Postinflammatory hyperpigmentation: A comprehensive overview.Journal of the American Academy of Dermatology. (October 2017).

5. Andrea L. Zaenglein, et al. Guidelines of care for the management of acne vulgaris. J AM ACAD DERMATOL. (MAY 2016).

6. Al-Niaimi, F., et al. Topical vitamin C and the skin: Mechanisms of action and clinical applications. Journal of Clinical and Aesthetic Dermatology. (July 2017).

7. Levin, J. and Momin, S.B. How much do we really know about our favorite cosmeceutical ingredients?Journal of Clinical and Aesthetic Dermatology. (February 2010).

8. Schwartz, C., et al. Hydroquinone. StatPearls. (2022 August 25).

9. Babilas, P., et al. Cosmetic and dermatologic use of alpha-hydroxy acids. Journal of the German Society of Dermatology. (2012 January 24).

10. Malinauskiene, L., et al. Formaldehyde may be found in cosmetic products even when unlabelled. Open Medicine. (2015).

11. U.S. Food and Drug Administration. Alcohol free. (2022 February 25).

Donna McIntyre is a board-certified nurse practitioner at Curology. She obtained her Master of Science in Nursing at MGH Institute of Health Professions in Boston, MA.

* Subject to consultation. Subscription is required. Results may vary. 

Written by

Curology Team

Medically reviewed by

Donna McIntyre, NP-BC