Do’s and Don’ts
By Louise Hidinger, Ph.D.
Skin issues like fine lines, acne breakouts and hyperpigmentation can sometimes happen all at the same time. Given the wide variety of skin care products out there, it is very tempting to use a slew of different products all at the same time, in the hopes of treating everything at once. But before you jump in and start piling on the products, watch out: certain combinations cancel each other out, and other combinations can actually make matters worse. When it comes to using multiple skin care treatments, here are some basic rules:
Don’t be tempted to combine treatments that exfoliate the skin, e.g. retinoids, chemical peeling agents such as alpha hydroxy acids, and mechanical exfoliants like scrubbing beads, scrub mitts and mechanical brushes. Although exfoliation is great for removing build-up of dead skin cells and revealing younger, fresher-looking skin, there is such thing as too much of a good thing. Over-exfoliation can dry out the skin, and cause irritation and inflammation, and acne breakouts. In the worse case scenario, over-exfoliation can damage the skin and cause scarring and hyperpigmentation.
Don’t combine benzoyl peroxide with active ingredients that are readily oxidized, otherwise the two ingredients will react together, thus destroying the potency of both benzoyl peroxide and the active ingredient. Benzoyl peroxide is the active ingredient in many topical acne treatments. Benzoyl peroxide is a strong oxidizing agent and this property is what allows it to kill bacteria responsible for acne.
Easily oxidized active ingredients include retinol and most types of retinoids (with the exception of adapalene), skin lightening agents arbutin and kojic acid, and all anti-oxidants including ascorbic acid (Vitamin C) and ascorbic acid derivatives, Vitamin E and ferulic acid. It’s still possible to treat acne with benzoyl peroxide and use retinoids and antioxidants, but their use has to be spaced out.
If you need to zap pimples while using other treatments like retinol, our consulting dermatologist Dr. Lisa Kellett recommends spacing out applications: “As an example, you can apply benzoyl peroxide after coming from work, and then before going to bed, wash off the benzoyl peroxide and apply retinol serum and/or Vitamin C serum by titrating a few drops of the serum into your moisturizer.” By doing so, the benzoyl peroxide treatment has about 4-5 hours to do its work before the retinol treatment is applied.
Exfoliating treatments such as topical retinol and chemical peels will temporarily make skin more fragile and sensitive to irritation.
Don’t use products containing a lot of fragrance. Fragrance, whether it is synthetic or naturally derived, is almost always the cause of skin irritation and allergic reactions. Also, try to avoid or limit use of alcohol-based toners and strong cleansers that will dry out the skin. Instead, Do use a lightweight water-based oil-free or low-oil moisturizer that will help to protect skin and keep it hydrated without clogging pores.
If you are applying multiple skin care products, Do remember to apply products in order of their solubility: a general rule of thumb is to apply anything water-based, such as a water-based serum, then moisturizer, with sunscreen as the final layer for daytime. To make things easy, you can do as Dr. Kellett suggests, which is to add a few drops of your treatment serum to your moisturizer and mix it up before applying to skin.
Do feel free to combine retinol with antioxidant serums. The antioxidants will not only help to inhibit free radical damage to your skin but they will also inhibit oxidation of retinol, maximizing the amount of active retinol reaching the actively dividing cells of the epidermis.
Do use a sunblock with minimum SPF30 and practice good sun protection, no matter what kind of treatments you are undergoing.
If in doubt about how to combine products, ask your dermatologist for help in setting up a skin care regimen that can incorporate treatments with different active ingredients.
About the Author Louise Hidinger is a Toronto-based cosmetic chemist.