Yes, you can use peptides and retinol together in one routine. We'd bring them in one at a time, starting with Collagen and Retinol Serum on two evenings a week and adding Firm Serum in the mornings about a month later. If you later add Firm Serum in the evening, use it only on nights without retinol. Wear sunscreen every morning while you're using retinol. The research we cite never tested the two together, so this plan is ours.
We make every product linked in this guide, and we don't publish the percentage of retinol in Collagen and Retinol Serum or of peptides in Firm Serum.
Peptides and retinol together, week by week
Add one serum at a time. The American Academy of Dermatology (AAD) warns that using several anti-aging products at the same time can irritate your skin, and irritated skin makes signs of aging more noticeable.
- Weeks 1 to 4. Collagen and Retinol Serum on Monday and Thursday evenings, starting with whichever comes next. Any two evenings a few days apart are fine; these two are just easy to remember. After cleansing, pat your face dry and smooth on a thin layer, away from the eye area and the creases beside the nose. Moisturizer goes on top. Other evenings get cleanser and moisturizer, and mornings get the same plus sunscreen.
- Week 5. Firm Serum joins your mornings. Sweep a thin layer upward on clean skin, from the neck to the jaw and then along the cheekbones, and follow with moisturizer and sunscreen.
- Week 7. Firm Serum also goes on the five evenings without retinol, with moisturizer after it. Its directions say morning and evening; starting with mornings only, and keeping it off retinol evenings, is our suggestion.
- Week 9 or later. A third retinol evening, if you want one, goes on Saturday, and Firm Serum comes off that night. Add any more the same way, one evening at a time.
Move to the next step only after two comfortable weeks in a row. By comfortable we mean no stinging, no tightness and no flaking. If any of those three show up, pause the serums and follow the stinging steps below.
From week 7, a normal week looks like this.
- Every morning: cleanser, Firm Serum, Active Eye Cream if you use it, moisturizer, sunscreen.
- Monday and Thursday evenings: cleanser, Collagen and Retinol Serum, a quick fingertip rinse, Active Eye Cream if you use it, moisturizer.
- The other five evenings: cleanser, Firm Serum, Active Eye Cream if you use it, moisturizer.
Neither serum's directions mention layering or say which goes first, so rather than guess at an order, we give each its own slot.
For the moisturizer step, go by feel. Oil-Free Daily Moisturizer is our light, oil-free fluid, and Hyaluronic Moisturizer is our rich cream. The cream contains a fragrant oil, so if your skin is sensitive, try it on a small patch before you use it over retinol.
Sunscreen is the last step every morning for as long as you use Collagen and Retinol Serum. The AAD's advice on retinol and other retinoids goes further, calling for sun protection every day, shade and clothing included. We don't sell sunscreen, so use your own. Pick one that's broad-spectrum and water resistant with SPF 30 or higher, then reapply about every two hours, and again after swimming or sweating.
Already using one of them?
If Firm Serum is already in your routine and agrees with your skin, keep using it as you do, minus Monday and Thursday evenings. Those go to Collagen and Retinol Serum. Retinol is the only new thing, so you're still adding one serum at a time, and the two-week rule applies before any third retinol evening.
Collagen and Retinol Serum users with a comfortable month behind them can start at week 5. Those already past two retinol evenings a week can keep them as they are and give Firm Serum their mornings first, then the evenings without retinol two comfortable weeks later.
With another brand's peptide or retinol, follow its label on timing and order. Where it says nothing, give it the slots our version gets in this plan.
What to leave out while you're on retinol
- Exfoliating scrubs and acids. We'd skip them while you're on this plan; the AAD warns that exfoliating while using retinol products "may worsen dry skin or even cause acne breakouts." To keep an acid you already use, follow the separate-evening schedule in whether an acid and retinol can share a night instead, keep Firm Serum to mornings, and for an alpha hydroxy acid (AHA) follow the FDA's advice to wear sunscreen and protective clothing, and limit sun exposure, while you use it and for a week after you stop.
- Other serums on retinol evenings, Firm Serum included.
- Either serum near your eyes. Collagen and Retinol Serum stays away from the eye area and the creases beside the nose, and Firm Serum's sweep stops at the cheekbones.
For the eye area, we make Active Eye Cream. It has the same peptide pair as Firm Serum, listed under older names (palmitoyl oligopeptide and palmitoyl tetrapeptide-3), and no retinol. Tap it gently along the orbital bone (the bony rim around your eye) with your ring finger, from the inner corner outward, morning and evening. Don't drag it, and keep it off the lash line.
We'd keep Active Eye Cream on retinol evenings, since it goes where Collagen and Retinol Serum doesn't. The order for those evenings is in our guide to eye cream before or after retinol.
If your skin stings
Pause both serums, or the one you're on so far. If one stings as it goes on, rinse it off with lukewarm water. Until your skin settles, it's cleanser and moisturizer only, plus sunscreen in the morning.
Hyaluronic Moisturizer contains a fragrant oil, so if that's your moisturizer, count it as a suspect too and switch to a fragrance-free one your skin already tolerates.
Once your skin has been comfortable for a full week, restart Collagen and Retinol Serum on two evenings a week. Firm Serum comes back after two more comfortable weeks. Going one serum at a time makes it easier to see which one your skin objected to.
See a board-certified dermatologist if the stinging or redness keeps coming back, or doesn't settle after you stop. Ask your doctor before starting retinol or any other retinoid if you're pregnant, trying to conceive or breastfeeding. For dryness rather than stinging, look at where moisturizer goes in the retinol sandwich method.
What a retinol trial and a peptide review found
In a 2007 trial by Kafi and colleagues at the University of Michigan, study staff applied a 0.4% retinol lotion to one arm of 36 people with a mean age of 87, up to three times a week for 24 weeks. The other arm got the same lotion without retinol. It was a randomized, double-blind trial, meaning chance picked the retinol arm and neither the volunteers nor the researchers knew which one it was.
By the end, fine wrinkles on the retinol arm had improved compared with the other arm. The US National Institutes of Health was among the funders. It's careful work on the arms of elderly volunteers, and it didn't test faces or our serum, whose retinol percentage we don't publish.
Firm Serum's peptides are palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7. Ferreira and colleagues, in a 2020 review in the journal Cosmetics, note that the two are frequently used together in the ingredient Matrixyl 3000.
Across the peptides it reviewed, the same review says most available clinical studies were performed by ingredient suppliers to generate claims for their ingredients, and are not usually published in peer-reviewed journals. None of this is research on Firm Serum itself.
Neither serum is a facelift in a bottle, and the AAD says as much about any cream: "You cannot get the results of a facelift from a cream."
"Most products take at least six weeks to work," the AAD says, and "sometimes it can take up to three months." So we'd give a routine at least six weeks before judging it, and stop sooner if anything stings.
Peptide and retinol questions
Can you use peptides and retinol at the same time?
In the same routine, yes, but with LYTA's serums we'd use them at different times of day or on different evenings. Collagen and Retinol Serum starts alone on two evenings a week, and Firm Serum joins in the mornings about a month later, then takes the evenings without retinol. The American Academy of Dermatology notes that several anti-aging products at once can irritate skin, hence the staggered start. Wear sunscreen every morning while using retinol.
Do peptides or retinol go first?
In our routine, neither LYTA serum goes on top of the other. Their directions don't cover layering, so Collagen and Retinol Serum gets retinol evenings to itself and Firm Serum takes the mornings and the other evenings. With other brands' products, their instructions come first. If those don't give an order, we'd use the peptide in the morning and the retinol at night, since the American Academy of Dermatology advises using retinol only at night.
Can peptides replace retinol?
We can't say, because nothing we cite compared the two. In Kafi and colleagues' 2007 trial of 36 people (mean age 87), study staff put 0.4% retinol lotion on one arm for 24 weeks, and fine wrinkles improved compared with the arm given the same lotion without retinol. Ferreira and colleagues' 2020 peptide review notes that ingredient suppliers ran most available clinical studies on the peptides it covered, and that these usually aren't published in peer-reviewed journals.
How long do peptides and retinol take to work?
The American Academy of Dermatology says most anti-aging products take at least six weeks to work, and sometimes it can take up to three months. We don't attach a timeline to LYTA's serums. Stinging is no sign of progress; the Academy notes that irritated skin makes signs of aging more noticeable.
Sources
- US Food and Drug Administration. Alpha Hydroxy Acids.
- Kafi R, Kwak HS, Schumacher WE, et al. Improvement of naturally aged skin with vitamin A (retinol). Archives of Dermatology, 2007.
- Ferreira et al. Trending Anti-Aging Peptides. Cosmetics, 2020.
- American Academy of Dermatology. Retinoid or retinol?
- American Academy of Dermatology. How to maximize results from anti-aging skin care products.
- American Academy of Dermatology. How to select anti-aging skin care products.
- American Academy of Dermatology. How to safely exfoliate at home.
- American Academy of Dermatology. Sunscreen FAQs.
