Your Guide to Healthy, Beautiful Skin

Here's what your doctor wants you know.


Use a broad spectrum (UVA/UVB) sunblock of SPF 30 or higher, every day, regardless of the weather or time of year. UVB represents the “burning rays” and UVA represents the “aging rays”. SPF stands for “sun protection factor” but only relates to the protection against UVB. SPF 30 blocks 97% of UVB, whereas higher SPF is only marginally better, with SPF 50 blocking 98% and SPF 100 blocking 99% of the UVB. For optimal protection against both types of UV rays and visible light, look for sunblocks with high zinc oxide content, and reapply every few hours when actively in the sun. In addition, wear sun protective clothing, hats, and sunglasses.


These are specialized forms of vitamin A required by multiple skin cell types for proper function. Examples: tretinoin, retinol, retinyl palmitate, retinyl acetate. Dr. Kenner calls these molecules “the great skin normalizers”, as retinoids have many skin benefits, including: skin cancer protection, enhancement of skin tone, quality, and barrier; improvement in wrinkles, acne, scars, stretchmarks, rosacea, milia, pigmentation, precancerous lesions, psoriasis and much more! Sunlight causes a deficiency of vitamin A in skin, causing “photoaging” and other problems, and is best managed with daily topical replenishment, for everyone.
Tolerability, stability and efficacy of retinoid products vary greatly, and can cause irritation or other skin problems in certain formulations.
Many Rx and non-Rx retinoid formulations are available. Some are poorly stable (like retinol), others irritating (like some forms of tretinoin), while others can be enfolded in clever carrier molecules, or in novel formulations, that can be tolerated on sensitive skin such as eyelids or children’s skin. With knowledgeable guidance, vitamin A products can be found for skin of all ages and sensitivities.

Unlike oral retinoids (such as isotretinoin), which get into the bloodstream and can harm a growing child, TOPICALLY applied retinoids don’t carry this risk for pregnant women. Nevertheless, in an abundance of caution, Dr. Kenner simply requests that all women stop the use of topical retinoids when they are pregnant. The products can be used while trying to become pregnant or while nursing.

Vitamin Antioxidants

The key vitamin antioxidants for protecting, repairing and renewing skin are Vitamins C and B3 (niacinamide/niacin). Critical functions include antioxidant activity, collagen production, normalization of pigmentation, repair of the barrier function, and protection against skin cancer. As with vitamin A, these critical skin vitamins are selectively deficient in sun damaged skin. Replenishing them at the sites of damage will allow the skin to grow and behave in a healthy fashion. Notably, however, unlike vitamin A, vitamins C and B are water-soluble, and cannot in their native forms penetrate the lipid barrier of our skin surface. Finding formulations that have encased or modified the vitamin C and B molecules in lipidized forms are key to both the stability of the products and to the efficacy! These can be difficult to find, as it takes formulation skill and specialized packaging. Most companies choose easier or cheaper routes, and while these may indeed be formulas that “contain” these critical vitamins, they may not be able to get through your skin! Or, because these native vitamins are susceptible to destruction in heat, light and air, they may be oxidized and non-functional by the time you open the jar! As with retinoids, Dr. Kenner is very particular about her product recommendations within this category.

Alpha and Beta Hydroxy Acids (AHA/BHA)

These naturally occurring fruit or milk acids, can help gently exfoliate dead surface skin/plugs/rough areas, and encourage the creation of newer healthy skin, as well as enhance the penetration of follow on products. Examples include, glycolic acid, salicylic acid, and lactic acid, and can take the form of cleansers, toners, creams or in office chemical peels. AHAs/BHAs are not tolerated by all skin types, especially those with rosacea, and can cause problems if not used properly. Particularly concerning is overuse-which is not uncommon due to the ready availability of these agents- leading to over-thinning of the skin and excessive UV damage.

Botanical antioxidants

Like the vitamin antioxidants, there are several plant derived molecules that can protect against the degradative effects of light on skin. These come from a great variety of plants such as fern, coffee, green tea, soy, grapeseed, and many more. In addition to quenching free radicals, many botanical agents can also have anti-inflammatory and anti-cancer effects. Importantly however, these products are relatively new to formal study in human skin, and many questions remain regarding formulation, dosing, and benefits. Marketing on the naturalness of products has nothing to do with actual skin penetration, safety, or benefit. More study is needed on many of these products which show promise.


These are small fragments of proteins, often seen by the body after injury, which can provide a variety of functions such as stimulation of collagen and elastin, creating skin repair and remodeling, and functioning like signals to turn on and off activities like muscle movement, thereby mimicking the effects of neurotoxin. Examples are: acetyl hexapeptide-3, palmitoyl pentapeptide-3, and palmitoyl oligopeptide-3. These molecules show promise, but need more human research.
Growth factors. These are molecular signals which direct cells to grow and develop into specialized mature tissues. Examples are: beta-NGF, EGF, FGF, CSF, VEGF, cytokines, etc. Growth factors are most prominent in embryonic and early stages of life, but can be reactivated in certain settings. The use of growth factors in skin has been employed to encourage new collagen formation and skin/wound repair and rejuvenation. Most formulations of growth factors are derived from immortalized fetal skin cell lines, or newborn foreskin samples, although growth factors also can be derived from mammalian colostrum. Benefits on human skin need to be studied further and source quality should be verified.