What Not to Mix With Copper Peptides

Copper peptides can work wonders for your skin and hair, but only if you let them work their magic without anything else getting in the way. Knowing what NOT to mix with copper peptides is just as important as picking the right formula and applying it consistently.

Here’s what you shouldn’t layer alongside our copper peptide serum:

• Vitamin C
• Retinoids
• Benzoyl Peroxide
• Aggressive Acids

Now, we’re not saying you can’t use these ingredients in the same skincare routine. Just that you can’t use them at the same time, or potentially even on the same days. Proper layering is paramount to getting good results with GHK-Cu or AHK-Cu. Learn more below! 

Benefits of Copper Peptides For Skin and Hair

First things first - why add copper peptides to your skin and hair routine? Because they basically tell your skin to start acting like it used to back in the day! GHK-Cu and AHK-Cu are signal peptides that can have powerful effects on your skin and hair appearance.

GHK-Cu is among the most popular copper peptides for skin. We know a lot about its ability to support firmer skin, smooth the appearance of fine lines, and even help hair look fuller over time. AHK-Cu may be a bit lesser-known, but the evidence thus far is really exciting for hair thickness.

Here at PLU Laboratories, we’ve paired GHK-Cu with Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7 to bring out the best in your skin. Meanwhile, our copper peptides for hair pair GHK-Cu with Acetyl Tetrapeptide-3. These pairings have been meticulously chosen with both effectiveness and safety in mind.

That matters because the wrong pairings can cause more harm than good. On that note, what should you NOT mix copper peptides with? 

What Not to Mix With Copper Peptides

There’s no chance copper peptides are the only thing in your skincare or haircare regimen. You probably rely on quite a few active ingredients to look and feel your best. It’s just that layering some of these in the same routine as copper peptides can impact results, or worse, lead to adverse reactions. Here’s what not to mix with copper peptides. 

Vitamin C (L-Ascorbic Acid)

This is the strongest form of vitamin C available, and it’s the most common in skincare formulas. It has powerful brightening properties and works as an antioxidant, shielding your skin from the damage free radicals can cause.

So what’s the connection between copper peptides and vitamin C? They MUST be separated by time. We prefer vitamin C in the morning and copper peptides at night. 

This matters because L-ascorbic acid is a reducing agent. Copper is an oxidizing metal ion. Vitamin C donates electrons to the copper when you put them together. The ascorbic acid can be oxidized into a useless byproduct. It could even generate free radicals in the process. The exact opposite of what either product is supposed to do.

Retinoids (Either Retinol OR Tretinoin)

Whether it’s retinol or tretinoin, these skincare staples increase skin cell turnover to help firm up skin. They’re also commonly used for acne treatments or fading dark spots. But as far as what not to mix with copper peptides, you’ll see retinoids on the list.

It’s just because this combination can overwhelm the skin since there’s quite a bit of overlap. Retinoids increase skin turnover while copper peptides support the appearance of firmness. Pairing them in the same ritual can cause redness, peeling, and general irritation.

So, can I use copper peptides with retinol? What about GHK-Cu vs tretinoin? Yes, and yes. It’s just a matter of alternating nights. This is a safer approach than splitting them up with an AM/PM layering routine. We actually have quite a few customers who use our copper peptides as part of their prescription tretinoin regimen to offset some of the discomfort!

Benzoyl Peroxide

This oxidizer kills acne-causing bacteria, helping stop blemishes before they take hold. It’s very aggressive and doesn’t discriminate between good and bad bacteria, though. It will attack copper peptides just like it does the pesky bacteria that causes acne.

That means if you apply both, the benzoyl peroxide gets to the copper first and the peptide never reaches your skin intact. You should separate them by at least 12 hours if both belong in your routine. Or, dedicate certain days to acne treatment and others to peptide application.

Aggressive Acids (Glycolic, Lactic, Salicylic)

Last but not least on our list of what not to mix with copper peptides, we have intense acids:

• Glycolic Acid
• Lactic Acid
• Salicylic Acid

AHAs and BHAs drop your skin’s pH down to the 3.0 to 4.0 range. Copper peptides are formulated for a higher, more neutral pH. That mismatch alone can destabilize the peptide structure before it absorbs.

We’ve found glycolic acid to be the worst offender because it’s the smallest molecule, which means it penetrates the fastest and drags that low pH effect deep into the skin. At the risk of sounding like a broken record, you just need to separate them by time of day (or by day altogether).

You Can Still Pair Them, You Just Have to Be Strategic!

We’re not here to tell you that you must drop everything from your routine except for copper peptides. You just need to know when to use each skincare ingredient so each can work to its full potential without causing any discomfort along the way.

Two ways you can go about that - separating by time of day (AM/PM applications) or by alternating days (known as skin cycling). 

There are lots of other ingredients copper peptides play nicely with. Hyaluronic acid, niacinamide, ceramides, and simple moisturizers all support hydration and skin barrier integrity without getting in the way of copper peptides. 

We recommend you apply your GHK-Cu serum at night on clean skin, let it absorb for 30 seconds, then layer a plain moisturizer if needed. Move your acids, retinoids, and vitamin C to the morning or alternate evenings.

Same idea for AHK-Cu peptide. Apply it to a clean, dry scalp and let your hair follicles soak in all the good stuff without anything else blocking absorption. You can learn more about AHK-Cu vs GHK-Cu in our blog.

We hope this guide on what not to mix with copper peptides has left you with clarity on how you can make the most of these powerful signal agents in your skincare regimen. All that’s left to do is stock up on the best copper peptides for any purpose, right here at PLU Laboratories!

Frequently asked questions 

What not to mix with GHK-Cu peptide?

Direct acids (glycolic, lactic, salicylic), L-ascorbic acid vitamin C, retinol, tretinoin, and benzoyl peroxide all either 1) oxidize the copper or 2) shift skin pH too low for the peptide to do its thing. You want at least 12 hours of separation between these ingredients and copper peptides. 

What can I pair copper peptides with?

Hyaluronic acid, niacinamide, ceramides, squalane, and basic moisturizers. Each hydrates the skin and supports your skin’s barrier without messing with the copper ion.

What’s the problem with using acids and copper peptides together?

It mostly comes down to pH. Copper peptides prefer a neutral pH to perform to their full potential, and these acids bring your skin down to the 3.0-4.0 range. The acidic environment breaks down the peptide structure before it can actually get into your skin where it’s needed.