If you're not much of a skin-care fanatic, it can be frustrating to take the time to pile multiple products on your face every day, especially when you may not notice the positive effects as soon as you'd hope.
@aminathepharmacist, a pharmacist on TikTok, understands the struggle. To encourage people to stick with their skin-care routine — even when they've yet to see any visible change — she posted a viral TikTok video explaining the average time it takes for popular skin-care ingredients to work. (Related: Unicorn Body Butter Is Taking Over TikTok Right Now)
"Vitamin C = 3 weeks, Salicylic acid = 12 weeks, Benzoyl peroxide = 12 weeks, Hyaluronic acid = a few mins, Retinol = 8-12 weeks, AHA = right away, Caffeine = a few hours," read her video captions. She recommended taking a screenshot at the end of her video and saving the photo "to remind yourself when you lose patience with skin-care." (Related: The Exact Order to Apply Your Skin-Care Products)
Amina's skin-care breakdown is no doubt helpful, but it doesn't exactly tell you everything you need to know about how these different ingredients work (and, more importantly, when they work).
For starters, each of these ingredients comes with its own set of uses and benefits, says Janelle Vega, M.D., a board-certified dermatologist and co-founder of BIA Life. Take vitamin C, for example. The skin-care ingredient has both antioxidant effects (meaning it can help reverse skin damage caused by exposure to UV rays and pollution) and brightening abilities. A three-week timeline doesn't apply to both of these benefits, as it takes varying lengths of time to achieve each of these results, explains Dr. Vega. (More on those exact timelines in a bit.)
It's also unclear whether @aminathepharmacist classifies "working" as being the moment you notice any change to your skin or when you experience the maximum intended results. Michelle Henry, M.D., a board-certified dermatologist and dermatologic surgeon, says you can often notice a product's effectiveness early on (i.e. in a matter of days, if not sooner), but it may take several weeks to attain the full results the product aims to achieve.
FWIW, @aminathepharmacist has since posted more videos going into detail on each skin-care ingredient's timeline. But if you don't feel like scrolling through TikTok and taking notes, here's a derm-approved breakdown of the timelines behind these popular skin-care essentials.
As mentioned, vitamin C is an antioxidant and brightening agent, but these benefits aren't necessarily delivered simultaneously. On the antioxidant side, vitamin C's ability to protect the skin from free radical damage starts immediately upon application, says Dr. Vega. As for brightening, this requires vitamin C to dissolve discolored skin cells and prevent the formation of new spots, so the visible effects aren't as instantaneous. You might notice vitamin C's brightening effects beginning at around four weeks, says Dr. Henry, but maximum improvement requires up to 12 weeks of consistent use. She recommends Clinique Fresh Pressed Daily Booster with Pure Vitamin C (Buy It, $21, clinique.com), while Dr. Vega suggests Skinceuticals CE Ferulic Vitamin C Serum (Buy It, $166, dermstore.com). (Related: The Best Face Scrubs to Achieve Bright, Smooth Skin).
Meant for reducing blackheads and chronic acne, salicylic acid can take several weeks to deliver a noticeable difference in your skin. For peak improvement in the appearance of acne, Dr. Henry agrees with @aminathepharmacist's 12-week timeline, though she notes that you may see some changes as soon as six weeks. Dr. Henry's go-to salicylic acid pick is Clinique Acne Solutions Clinical Clearing Gel (Buy It, $19, clinique.com), while Dr. Vega recommends Skinceuticals Blemish Age Defense Serum (Buy It, $92, dermstore.com).
Benzoyl peroxide creates an environment that kills bacteria linked to inflammatory acne — and this happens pretty quickly. Dr. Henry says you may see early improvement within two weeks. But after killing the bacteria, Dr. Vega says it'll take at least six to eight weeks to eliminate pimples and redness and achieve acne resolution. Dr. Henry is a fan of CeraVe Acne Foaming Cream Cleanser (Buy It, from $21, amazon.com), while Dr. Vega suggests PanOxyl Acne Foaming Wash (Buy It, $9, amazon.com).
As a humectant, when hyaluronic acid enters the skin, it draws water and holds it within your skin. Depending on how it's formulated, this ingredient can make your skin plump and hydrated within just a few minutes to a few hours, says Dr. Henry. She likes L'Oréal Paris Revitalift Filler 1.5% Hyaluronic Acid Serum (Buy It, $19, amazon.com), while Dr. Vega prefers BIA Life's Hydrating Elixir (Buy It, $88, bialife.com).
A popular anti-aging skin-care ingredient, Retinol helps increase the production of molecules that encourage skin-cell turnover (read: less discoloration and smoother skin) and collagen production (i.e. fewer wrinkles). "Because retinol needs to harness the body's cellular machinery, the visible effects of skin turnover can take four to 12 weeks," explains Dr. Henry. The beneficial results from collagen production, on the other hand, will likely take longer — around eight to 12 weeks, says Dr. Vega. In addition to these long-term benefits, retinol also helps unclog your pores, a purging effect that's most noticeable in the first six weeks of use. Dr. Henry's favorite retinol? Olay Regenerist Retinol 24 Night Serum (Buy It, $47, amazon.com). (Here are the best retinol products for every skin type, according to top derms.)
To slough off dead skin cells and achieve the desired glow from using alpha hydroxy acid (AHA), Dr. Henry says it can take one to two weeks to see early improvement and several weeks for your final result. If your goal is to correct skin pigmentation, Dr. Vega says you should expect to wait a lot longer, as this outcome requires at least eight to 12 weeks before it's noticeable. She recommends Skinceuticals Glycolic 10 Renew Overnight Cream (Buy It, $80, dermstore.com).
Caffeine constricts blood vessels to reduce puffiness of the skin, especially around your eyes. While this action is quick, Dr. Henry says that the type of formula carrying the caffeine can influence whether the ingredient takes a few hours (as @aminathepharmacist suggests) or up to one day, as Dr. Vega estimates. Dr. Henry suggests trying Garnier SkinActive Clearly Brighter Anti-Puff Eye Roller (Buy It, $9, amazon.com), while Dr. Vega recommends Replenix Serum CF (Buy It, $94, dermstore.com).