This article, re-posted from newbeauty.com by Liz Ritter, Executive Managing Editor, is a good reminder that even though a product that may seem less efficacious over time, it's still doing it's job. In fact, it probably means your skin is getting stronger and healthier!
Myth 1: Retinol Has a Time Limit
Your retinol’s only time limit is its expiration date. “This ingredient should be used indefinitely,” says Dr. Goldberg. “Whether you use an over-the-counter retinol or prescription one, if you stop seeing its benefits, all that means is that you need to switch to a stronger dosage,” Miami dermatologist Leslie Baumann, MD, adds.
Myth 2: If You Aren’t Getting Red, It’s No Longer Effective
And what about acids and other ingredients that sometimes are met with a sort of ‘transition’ phase (that period where your skin experiences redness and reactivity) on more sensitive skin types? “Glycolic acid has been shown to increase the skin barrier, so with prolonged use, less gets absorbed,” Dr. Baumann says. “Some people may say that’s getting used to it, but that’s the end goal—you want a more built-up skin barrier.”
Myth 3: Your Body Can Build a Resistance to Botox
While there is a very small chance of developing antibodies to a neuromodulator (which wouldn’t necessarily pose a threat to your health, but would result in it no longer working on you), this has never been reported under cosmetic uses, and has only been seen in cases where subjects were treated for muscle spasms. “These cases aren’t good examples because the subjects are treated with much higher doses,” Dr. Baumann says. Dr. Goldberg adds that there are no instances of this across the board—including in fillers, injectables and fillers used in conjunction, and with other in-office treatments like chemical peels and lasers. “As time goes on and a person ages, the dose of Botox needed may increase, but that’s not an immunity; it’s simply due to increased aging,” says New York dermatologist Jody Levine, MD.
Myth 4: Your Favorite Shampoo Will Eventually Stop Working
Dr. Baumann says the only one you really need to worry about is dandruff shampoo (which, according to the FDA, is actually both a drug and a cosmetic, so it doesn’t fall on strictly the ‘beauty product’ side). “I often recommend that patients with dandruff keep three anti-dandruff shampoos in the shower and randomly choose one with each wash, as I do think that the scalp becomes less responsive to the same shampoo when used with every wash,” says Dr. Levine.
Truth: Your Age Can Make Certain Products Less Effective—and So Can Air
Unlike a fine wine, time doesn’t age products in a positive way—and certain products become ineffective quite quickly when exposed to an everyday culprit: air. “Vitamin C is a good example of a product that, when oxidized, loses its efficacy,” says Dr. Levine. “Likewise, the body’s response to products is less robust with age. Hence a product or procedure intended to increase collagen building in an older person will not be as effective as it would be in a younger person.” But, this concept has its benefits, too. “Older skin is less likely to make as big a scar as younger skin will,” Dr. Levine explains. “A facelift in an older person can be virtually scar-less despite incisions, whereas a younger person will have more prominent scarring.”