Is the Peptide Booster good for sensitive skin? It’s totally fine to use the Peptide Booster, even if you have sensitive or rosacea-prone skin. This gentle formula contains soothing and replenishing antioxidants that calm and counteract irritation. Is the effectiveness of the Peptide Booster reduced if I mix it with other products? No, this formula was designed to complement the ingredients in our serums, treatments and non-SPF moisturizers. Is it OK to mix the Peptide Booster with my sunscreen? No, you should never mix any skin care product into sunscreen— it dilutes its powers and efficacy. Instead, apply the Peptide Booster on its own or mix it with your favorite serum, treatment or non-SPF moisturizer, then finish with your SPF moisturizer. In any daytime routine, sunscreen rated 30+ should always be the last product you apply. Does the Paula’s Choice Peptide Booster contain Matrixyl? The Peptide Booster does contain matrixyl, but not the original version, which was known as Palmitoyl pentapeptide-4. We’re using what’s known as Matrixyl 3000, which includes the peptides Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7. It’s essentially a next-generation peptide blend. Matrixyl isn’t listed on our ingredient list, as it’s a trademarked name. Some brands call out trademarked names in marketing copy, but they’re required to list the INCI (International Nomenclature Cosmetic Ingredient) names. The full INCI name for Matrixyl 3000 is Glycerin (and) Aqua (and) Butylene Glycol (and) Carbomer (and) Polysorbate 20 (and) Palmitoyl Tripeptide-1 (and) Palmitoyl Tetrapeptide-7. Does the Peptide Booster help firm skin? Yes, the Peptide Booster can help visibly firm up your face, neck and chest. Can I use the Peptide Booster around my eyes? Yes, you can use the Peptide Booster on the skin around your eyes, just be mindful to avoid your lash line. Can I use the Peptide Booster with retinol? Yes, you can use the Peptide Booster with retinol products. Peptides and retinol complement each other’s skin-renewing, anti-aging benefits. Is Paula’s Choice Peptide Booster oil-free? Yes, the Peptide Booster is oil-free. Can you use hyaluronic acid with peptides? Yes, you can use hyaluronic acid and peptides together. They have a synergistic effect that helps increase supple, plump skin. Which peptides are best for skin? There is no single best peptide for skin. Instead, the most effective approach is to use a robust mix of peptides, as each offers its own unique mechanism of action to target specific skin concerns. When used together, they revive skin in ways that a single peptide can’t. Are peptides better than retinol? Peptides aren’t necessarily better than retinol—but that’s like comparing apples to oranges. They work in different ways, so it really depends on your specific concerns and what your skin responds best to. Generally speaking, retinol is more of an all-encompassing skin-improving ingredient, whereas each peptide has a highly specialized facet of skin that it addresses. There’s no reason you can’t use them together! What can you not mix with peptides? We have yet to discover an ingredient you cannot mix with peptides, assuming the product is well-formulated. Peptides are complementary, meaning they play well with other superstar ingredients. Can peptides be layered? Yes, peptides can be layered. Each peptide targets different aspects of restoring skin, so the more the merrier! Can you mix peptides and vitamin C? An imbalance of electrolytes can affect regular skin function and show up with easy-to-spot symptoms like dry, dehydrated or stressed skin. Consuming electrolyte-rich foods—think dairy, fruit, nuts and seeds—is important and applying electrolyte-rich skin care can further help improve water absorption and retention. Can you mix peptides and niacinamide? Yes, you can mix peptides and niacinamide. This combo is particularly helpful for those wanting to address signs of aging and enlarged pores at the same time.