This Peptide-Packed Serum Fights the Four Most Common Signs of Visible Skin Aging

Photo: Jamey Powell
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If you've scoured the interwebs looking for brightening skin-care products, you know there's no shortage of options out there. You've likely seen products that include vitamin C and niacinamide (or viamin B3), both antioxidants that are long hailed for their anti-inflammatory properties and ability to tackle hyperpigmentation. But what do you know about oxyresveratrol? TBH, I didn't know squat until I started using the Medik8 Oxy-R Peptides Serum.

This new serum from Medik8 aims to reduce the appearance of dark spots and promote a brighter, more even skin tone, using oxyresveratrol, two types of peptides, and other tried-and-true skin-care ingredients. Read on for everything you need to know before introducing it to your daily skin-care routine, plus my first-hand experience after using it for just one week.

What is oxyresveratrol?

The headliner of this particular show, oxyresveratrol1 (or Oxy-R), is a compound found naturally in peanuts, grapes, and some tree barks. Medik8's Oxy-R comes from the bark of the artocarpus lakoocha tree, which is in the mulberry family (and sort of sounds like a spell Harry Potter would cast). Fun fact: oxyresveratrol is a stilbene, a type of compound. The term "stilbene" is derived from the Greek word "stilbos," which means "shining."

So, what exactly does it do? Research suggests Oxy-R is a powerful antioxidant with anti-inflammatory and brightening capabilities. It works by blocking tyrosinase, a natural enzyme that produces melanin and other pigments in the skin. "Oxy-R has been used for centuries for natural skin rejuvenation," explains Daniel Isaacs, Medik8's chief product officer and founding partner. "It works to effortlessly transform the look of uneven skin tone by helping to prevent the formation of dark spots, caused by UV exposure, free radicals and skin injury (e.g. blemishes)."

It's worth noting that Oxy-R is actually rather volatile in skin-care products, especially at higher potencies—as is the case with this one percent formula. "Oxyresveratrol is a highly unstable ingredient, particularly when used at high strengths, it is sensitive to things like light, heat, and air. Therefore it needs to be carefully stabilized to utilize its full, potent potential," explains Isaacs. The solution? Medik8 divides the product into two separate click-activated bottles. When you finish one bottle, simply click the top of the second bottle to activate the Oxy-R and move the dropper over. "Formula stabilizers keep the Oxy-R fresh for six weeks, ensuring it remains potent until you finish each bottle," says Isaacs.

Other ingredients in Medik8 Oxy-R Peptides Serum


As board-certified dermatologist Joshua Zeichner, MD, previously told W+G, "Peptides are messengers that boost your skin cells' activity and have various functions depending on the particular peptide. Most have skin brightening effects." These small amino acids stimulate collagen growth, helping skin look and feel younger (yes, please).

The Oxy-R Peptides formula includes two types of peptides. The first is tetrapeptide-30, which Isaacs says helps minimize the production of tyrosinase. It also includes acetyl glycyl beta-alanine, a tongue-twister of a peptide that prevents melanin from reaching the skin cell and becoming visible on the skin's surface. "Oxy-R Peptides has a triple-threat approach to discoloration," says Isaacs.

Lactic acid

A form of alpha-hydroxy-acid (or AHA), this gentle chemical exfoliant lends a hand by encouraging skin cell turnover. As a result, lactic acid helps soften and smooth the skin, improves its texture, and reduces dark spots.

Hyaluronic acid

If you're not already using a product with hyaluronic acid, it's one bandwagon we highly recommend jumping on. This powerhouse molecule draws in and holds more than 1,000 times its weight in water. And, while moisturizing isn't necessarily the main goal of this serum, it's a great nice-to-have bonus.


Like hyaluronic acid, glycerin is another humectant that helps pull moisture into the skin. Again, this isn't a replacement for your routine moisturizer, but glycerin is a little helper you'll be happy to have.

What's not inside?

Medik8 puts serious TLC into their products, so it should come as no surprise that this vegan formula is free of artificial fragrances or colors, as well as phthalates, parabens, and alcohols. It's also worth noting that the brand makes significant sustainability efforts—you can learn more about their carbon emissions and waste reduction efforts by reading their 2023 Sustainability Report.

Does Oxy-R Peptides work?

I just started using this serum last week, so I expect it will take a little while to see significant results. Still—and it might be a placebo effect—I feel like my skin looks brighter already, even after one week of use.

It turns out I'm not alone in my optimism. Medik8 performed a small, independent clinical study on 35 participants, each with their own unique dark spot concerns. After eight weeks, the participants reported a more even skin tone. The brand also performed a slightly larger independent consumer study (this time with 50 participants). These folks backed up my brighter-after-seven-days theory and said they saw dark spots fade within just one month.

Who is Medik8 Oxy-R Peptides for?

Medik8 says this serum is safe to use for all skin types looking to brighten their complexion. According to Isaacs, Oxy-R Peptides is a good fit for:

  • Anyone with sensitive skin
  • Those who want to target the appearance of stubborn dark spots, uneven skin tone & post-imperfection marks
  • Deeper Fitzpatrick skin types2 (FP5-6), which include brown and black skin where visible dark spots can be more prevalent
  • Boosting an existing vitamin C & A regime for brightening results

And I can attest: I have combination skin and I sometimes experience breakouts when introducing new products to my routine. I haven't experienced any adverse effects—and I've used it both morning and night after washing my face and before applying my moisturizer and SPF.

Of course, everyone's skin is different. Especially if you have a specific skin condition, it never hurts to speak with your dermatologist before starting a new skin-care product.

Well+Good articles reference scientific, reliable, recent, robust studies to back up the information we share. You can trust us along your wellness journey.
  1. Likhitwitayawuid K. (2021). Oxyresveratrol: Sources, Productions, Biological Activities, Pharmacokinetics, and Delivery Systems. Molecules (Basel, Switzerland)26(14), 4212.
  2. Ward WH, Lambreton F, Goel N, et al. Clinical Presentation and Staging of Melanoma. In: Ward WH, Farma JM, editors. Cutaneous Melanoma: Etiology and Therapy [Internet]. Brisbane (AU): Codon Publications; 2017 Dec 21. TABLE 1, Fitzpatrick Classification of Skin Types I through VI. Available from: doi: 10.15586/codon.cutaneousmelanoma.2017.ch6

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