Best Retinol Serum: How to Judge One Without Trusting the Percentage
Shopping for the best retinol serum? Percentage is the least predictive number on the label. Here is what form, stability and delivery actually tell you.
Read article →
Evidence-Based Skincare Articles
Written by the North Biomedical® team to provide thoroughly researched content on skincare science, anti-aging breakthroughs, and the latest advances in dermatological technology.
Explore by topic
Six guided paths through the library
Loose, Crepey & Sagging Skin Understand why skin loses firmness and compare evidence-based options for crepey, loose, sagging, and wrinkled skin by body area. Open guide → Retinoids & Retinol A complete guide to retinol, retinal, tretinoin, adapalene, retinyl esters, Nanoretinol®, combinations, side effects, and routines. Open guide → Dark Spots & Uneven Tone Identify common causes of dark spots and uneven tone, then compare sunscreen, brightening ingredients, retinoids, and procedures by concern. Open guide → Mature Skin Routines & Common Concerns Build a practical mature-skin routine and explore product guides, skin types, barrier care, texture, pores, eye concerns, and age-specific needs. Open guide → Skincare Ingredients A–Z Browse evidence-based skincare ingredient guides covering antioxidants, acids, hydrators, oils, peptides, vitamins, barrier support, and more. Open guide → Procedures & At-Home Options Compare injectables, lasers, peels, energy devices, microneedling, tightening procedures, recovery, limitations, and at-home alternatives. Open guide →
Hydrating Face Mist: Does Spraying Water on Your Face Actually Hydrate It?
Does a hydrating face mist really hydrate? The science of what happens after you spray, why some mists dry skin out, and what to look for on the label.
Read article →
Skin pH: The Number That Quietly Decides Whether Your Skincare Works
Skin pH sits near 4.7 for a reason. Here is how surface acidity controls barrier enzymes, why it rises with age, and what that means for your routine.
Read article →
Best Sunscreen for Mature Skin: How to Choose SPF You'll Actually Use Every Day
The best sunscreen for mature skin is the one you apply generously every day. Here's what the clinical evidence says about SPF, UVA, tint, and texture after 50.
Read article →
Evening Primrose Oil for Skin: What GLA Can Do That Other Oils Can't
Evening primrose oil for skin is unusual: it delivers gamma-linolenic acid directly. Here's the evidence on barrier repair, hydration, and its real limits.
Read article →
Eye Serum vs Eye Cream: Which One Your Under-Eye Area Actually Needs
Eye serum vs eye cream: the difference is the vehicle, not the potency. Here's how occlusion, active loading, and thin eyelid skin should drive your choice.
Read article →
Is Drinking Water Good for Your Skin? What the Controlled Trials Found
Is drinking water good for your skin? Controlled trials show a real effect, but only in people starting from low intake. Here is where the ceiling sits.
Read article →
Humidifier for Dry Skin: What Running One Actually Changes
Does a humidifier for dry skin work? Here is what low indoor humidity measurably does to the skin barrier, the RH number that matters, and its limits.
Read article →
Silk Pillowcase for Wrinkles: What the Evidence Actually Supports
Does a silk pillowcase for wrinkles work? Here is what friction and sleep-crease research really shows, and the part of facial aging fabric cannot touch.
Read article →
Almond Oil for Skin: What an Oleic-Rich Oil Can and Can't Do
Almond oil for skin is a soft, oleic-rich emollient with real comfort benefits and one important barrier caveat. Here is what the evidence supports.
Read article →