The Active Ingredients That Go Deepest Into Your Skin
Ever wonder how deep your skin care is going? Lots of products promise it—but only certain ones can really attest to the claim.
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Molecule Size Matters
“Skin-care products that include ingredients with very small molecules, such as vitamin C and retinol (vitamin A) have the ability to penetrate the skin,” explains New York dermatologist Marina Peredo, MD. “The smaller the molecule in the ingredient, the easier it is for that product to penetrate.” In addition, St. Augustine, FL, facial plastic surgeon Deirdre Leake, MD, adds that lesser-known factors (you've probably never even thought of them!) like correct pH level, increasing the atmospheric pressure and the temperature all affect the penetration of an ingredient.
“There are plenty ingredients that penetrate the skin, but in the U.S. it is required to be a drug if it actually does that,” she adds. "In order for products to penetrate the skin, an emulsifier typically used to encapsulate the ingredient and deliver the molecules. The top layer of the skin is a strong protector against chemicals, bacteria, UV radiation, and loss of moisture, which prevents ingredients from entering and moisture from leaving the skin.”
So Does the Delivery System
Terms like “nanotechnology” and “microspheres” aren’t just fancy-sounding scientific words—these are the key indicators that let you know how a product is being delivered into your skin. “Liposomes and niosomes are used in the cosmetic industry as delivery vehicles,” Dr. Peredo says. Adds Annet King, director of global education at The International Dermal Institute and Dermalogica, “Microencapsulation is the process whereby an active ingredient is encased by microscopic capsules or spheres, to preserve the active molecule’s stability, facilitate a controlled release, and enhance penetration through the skin. Certain biologically-active ingredients are fragile and unstable (such as molecules that break down when exposed to light or air)." This encapsulation process protects them, and ensures their potency.
Some Ingredients Can Be Time-Released
Encapsulation helps both water-soluble and oil-soluble actives penetrate more deeply (water-soluble ingredients have difficulty penetrating the lipid membrane of the skin; oil soluble might be too unstable or large a molecule). “With some micro-encapsulation technology, the particles around the active or casing melts into the skins natural lipid layers between cells to form an ultra-thin, uniform film on the skin,” King explains. “This helps reduce transepidermal water loss, or evaporation of moisture within the skin, and also helps opens up pathways of the stratum corneum (outer-most layer of skin), so the active can penetrate deeply, delivering a controlled release of the potent ingredient over time.”
And Other Procedures Can Pump Up the Efficacy
According to Dr. Peredo, procedures such as lasers, and microneedling create small abrasions on the skin, which also allows skin-care ingredients to penetrate the skin—and so can exfoliation. “The better your skin is hydrated, the better penetration will be,” King says. “Certain electronic devices that have microcurrent or ultrasound will also aid penetration, so if you have them at home, use them over your encapsulated serum-type products, or see a professional skin therapist who can use them in the treatment room over more potent professional-grade products.”
So What Needs to Be Encapsulated?
According to King, many ingredients need a special delivery system, but it’s mainly those that are more unstable like retinol, vitamins or certain delicate botanical extracts, or if you just want the active to be targeted. So what doesn’t? “Peptides, as they are already tiny (i.e. amino acid chains or parts of proteins); essential oils, as they are absorbed via the hair and sebaceous follicle; and hydroxy acids might not require encapsulation.” In addition, Dr. Leake says antioxidants are meant to stay on the top layer of the skin, where their action is needed.
The Next Generation
“Newer structures such as solid lipid nanoparticles and nanostructured lipid carriers have been found to be better performers than liposomes,” Dr. Peredo says. “In particular, nanostructured lipid carriers have been identified as a potential next-generation cosmetic delivery agent that can provide enhanced skin hydration, bioavailability, stability of the agent and controlled occlusion. Encapsulation techniques have been proposed for carrying cosmetic actives. Nanocrystals and nanoemulsions are also being investigated for cosmetic applications.”