Below, skin, makeup, hair, and dental experts rank some of the worst beauty blunders from somewhat gross (don’t let it become a habit) to pretty gross (slippery slope!) to dangerously gross (and even potentially life-threatening), and offer advice for getting your hygiene back on track. Explanation: The human body is a fascinating thing. It also happens to be a breeding ground for dead skin cells, oil, sweat, dirt, and even pollutants. “Not washing your face regularly means that these aggressors sit on the skin for extended periods of time, blocking your pores and leading to inflammation, which can make you more at risk for ingrown hairs, acne breakouts, and effects of premature aging, such as dark spots and wrinkles. Bacteria and viruses can also build up, leaving you at risk for more serious infections,” explains Joshua Zeichner, MD, a board-certified dermatologist in New York City. Excessive cosmetic and skincare products, heat and activity, which can cause the body to produce additional oil and sweat, tend to make matters worse. “High-intensity workouts, especially where one is sharing mats and equipment with others, can expose one to additional germs and create an environment in which bacteria can flourish,” cautions Dr. Hadley King, MD, board-certified dermatologist of Hadley King Dermatology. Recommendation: To prevent breakouts and help minimize the risk of infection, opt for lightweight and ideally non-comedogenic products (remember to make one of them sunscreen), and aim to wash your face with a gentle cleanser one to two times (once in the morning and again at night) per day. Both Dr. Zeichner and Blair Murphy-Rose, MD, FAAD, a board-certified dermatologist in New York and clinical assistant professor at NY Presbyterian Hospital-Weill Cornell Medical Center, say that nighttime wash is the priority. “Removing dirt and makeup before bed keeps your pores cleaner and reduces the likelihood of clogging overnight. Maintaining excellent hygiene of your eye area is especially important, as the eyes are particularly susceptible to infection from bacteria left on or around the eyes and lashes,” cautions Dr. Murphy-Rose. When it comes to the body, Dr. Murphy-Rose says washing once a day should usually suffice, especially for those with drier skin types and during colder months. “Water is good for your skin, but excessive sudsing can strip your skin of the natural oils that help to keep skin hydrated. Unless you have been rolling on shared gym equipment, in which case you should you should always try to sneak in a quick post-workout cleanse, using soap only in areas that harbor bacteria (such as the underarms, groin area and feet) and just rinsing water along the rest of your body should do the trick,” Dr. Murphy-Rose explains. For application, she prefers a clean washcloth as opposed to reusable loofahs or puffs “that can harbor bacteria and mildew over time.” Nina Desai, MD, a board-certified medical and cosmetic dermatologist and founder and owner of Pure Dermatology and Aesthetics in Manhattan Beach, also recommends keeping showers short and water neutral (ideally lukewarm). “When you get out of the shower, pat—never rub—your skin dry with a towel. When skin is still moist, apply a moisturizer to help seal in hydration,” she adds. Explanation: Not washing your face before bed becomes particularly problematic when you’re wearing makeup that can clog up pores while you catch your Zzzs. According to Dr. King, thick, oil-based primers and foundations are the worst culprits for congestion, especially for skin that is already oily or acne-prone. “Conversely, mineral powder foundations, matte primers, and matte lipsticks can be extremely drying if left on overnight,” she says. In addition to having its own hydrating and drying properties, Dr. King says makeup can act as a sponge for air and other toxins. “This can cause increased and prolonged exposure to free radicals, further leading to the breakdown of collagen that can contribute to premature aging,” she explains. Experts point out that sleeping with eye makeup on in particular can take things from questionable to critical, resulting in irritation, allergic reactions, or more severe conditions, such as infections or a scratched cornea. “Leaving mascara on throughout the night can also make lashes more brittle and prone to breakage,” says King. Recommendation: Dr. Murphy-Rose suggests using a makeup remover (this one from Garnier tackles waterproof solutions), applied with a Q-tip for more delicate areas, then washing the face to rid skin of any leftover residue and microorganisms, and keeping a pack of hypoallergenic makeup wipes (she likes these fragrance-free wipes from Neutrogena) as a backup. “If you are particularly prone to eye infections or tend to wear heavy eye makeup, you can add a product like OCuSOFT Eye Lid Scrub ($10; amazon.com) a few times a week.” If you still manage to slip up, Dr. Zeichner says you’ll want to be extra vigilant the next morning. “Consider a double cleanse or adding a toner to your cleanser routine for additional clarity.” Explanation: Because brushes are in contact with your skin and makeup, they latch on to all of the same aggressors. “Bacteria in particular grows in warm, moist areas, and can build up in the bristles of your brushes, which can lead to breakouts, redness, and other skin irritations,” explains Justyna Santiago, a makeup artist and beauty expert in New York. According to Dr. Desai, that includes harmful bacteria like staphylococcus, streptococcus, and E. Coli, which can lead to more serious infections. Even if cleaning your face before each application, Santiago points out that bacteria can still accumulate. “When your makeup brushes aren’t being cleaned, you’re reapplying all of that bacteria back on to your face.” Recommendation: To keep bacteria at bay (especially important when it comes to eye makeup brushes given increased risk in that area), Santiago recommends using a spot cleaner, like Cinema Secrets Brush Cleaner ($24; sephora.com), between applications when possible. “This will also help remove oils and pigments so they won’t transfer and your makeup appears fresher.” You’ll also want to deep-clean brushes at least once a month. “I use Beautyblender Liquid Blendercleanser ($13; sephora.com), which does a great job of breaking down makeup and removes germs,” says Santiago. RELATED: How to Clean Your Makeup Brush Like a Pro Explanation: Looking for a quick pop of color? You might want to think twice about swiping your friend’s lipstick. “Sharing contaminated cosmetics and tools that directly touch the skin can spread microorganisms and potential infections,” says Dr. Zeichner. According to Dr. Zeichner, this is especially true of water-based formulas (which are more prone to bacteria growth) and products and tools that come in contact with bodily fluids, such as eye liners, lip glosses and anything that has the potential to break the skin surface. “The eyes are considered mucous membranes, and can easily become infected with microorganisms, causing conditions like pink eye or even herpes,” he warns. Recommendation: If you must share, Dr. Zeichner says the key is to ensure the formula itself is never contaminated. “If using the same liquid makeup, make sure that you are always using disposable applicators and do not double-dip. For example, you can use someone else’s mascara only if the wand has not been used and put back into the tube,” he explains. If sharing powder makeup, use a freshly cleaned brush (Dr. Zeichner points out that they can easily become contaminated), and be sure to thoroughly sanitize any shared tools before and after use. “And do not ever share tools, such as razors or dermaplaning devices, that are likely to come into contact with bodily fluids through cuts in the skin.” Explanation: When products expire, their formulas can change and active ingredients may be less potent and therefore less effective, says Dr. King. “Aside from not performing, outdated products are more prone to yeast or bacteria growth, which can cause skin irritations or infections,” she adds. As a general rule, once opened, Dr. King says liquid makeup should be replaced after six months, dry powders after two years, and mascara and liquid eyeliners after three months. For skincare, Dr. Desai says you can typically expect serums to last for six months to a year, moisturizers for one year, and sunscreen for two years. Recommendation: While gaining a sense of typical lifespans is helpful, both Dr. King and Dr. Desai say it’s best to have an expiration date for the individual product itself, as certain formulations, packaging, and ingredients can factor into timelines. “For example, vitamin C, retinol, probiotics, and some combinations of benzoyl peroxide tend to have shorter shelf lives, and some clean or natural products that lack preservatives may need to be tossed faster,” she explains. Dr. King also suggests keeping products stored in a cool, dry place to preserve the integrity of the formulas. “Ingredient degradation is less likely when products are not exposed to air, heat, and light, but can still happen over time.” And don’t forget to cleanse and/or change washcloths, sponges, cleansing brush heads, makeup brushes, and other applicators regularly. “When all else fails, use the sniff test—if it smells funky, throw it out!” advises Dr. King. Explanation: Natasa Billeci, RN, BSN, C-HWC, anti-aging nurse, health coach and co-founder of the Katan Klinic in New York, considers over-exfoliation one of the most common skincare faux pas. “Clients tend to self-prescribe with exfoliating over-the-counter scrubs and prescription-based products that strip skin of its natural moisture, which can result in transepidermal water loss and create microinflammation, compromising the structure and function of the skin over time,” Billeci explains. “Much like we see with chronic diseases, longterm inflammation of the skin can also lead to acne, eczema, rosacea, and dermatitis,” she adds. Recommendation: For at-home use, Katan Klinic co-founder Katherine Amato, LE, NCEA, HWC, suggests sticking with gentle cleansers and clay masks, ideally formulated with hydrating ingredients like lactic acid for keeping moisture levels balanced. “Avoid scrubs with large abrasive particles as these can cause micro-tears and fissures to the dermis if used too often or if the pressure applied during scrubbing is too strong,” Amato cautions. “The goal is to slough off the cellular debris on the very top layer of skin to reveal a fresh canvas. Leave the deeper work to the experts.” Billeci points out that those with more sensitive, thinner, or aged skin may want to opt for a gentle enzyme-based cleanser that exfoliates without the physical abrasion. “Enzyme washes can encourage healthy cell turnover as they munch away at the built-up skin cells and can be used one to two times per week depending on your skin type,” she explains. While you’ll still want to avoid very harsh scrubs, Billeci also says the skin on the body is typically thicker and much more resilient. “Scrubs, AHA-based exfoliants, and dry brushing are all fantastic for managing skin health, microcirculation, and cell turnover. Keep in mind that there is still a moisture balance factor to maintain, so adequate hydration immediately after exfoliation is a must.” Explanation: Another common—and perhaps more concerning—skincare trend Billeci and Amato have witnessed is clients taking matters into their own hands when it comes to picking blemishes and even attempting to perform their own extractions. “It just takes one poorly-done extraction to create a cascade of expensive and expansive skin issues, including a high risk of developing post-inflammatory hyperpigmentation and uncontrolled breakouts. Spreading bacteria below the surface of the skin and neighboring follicles will actually slow your progress and create issues where there weren’t any to start,” Amato warns. Recommendation: Billeci and Amato say professional facials and extractions are your best bet when it comes to blemish and blackhead control. “Timing for this is also dependent on one’s skin type. Some clients can get away with every six weeks, whereas others may need a cleanup every three to four weeks. Lifestyle, nutrition, travel, and compliance are also factors when timing out these treatments.” Explanation: According to Marc Lazare, DDS, MAGD, FABD, a cosmetic and biomimetic dentist in New York, many people neglect their mouths, either due to not having an understanding of or enough time for proper care, allowing for plaque to progress. “That plaque, which is mostly made up of bacteria, continues to build on the teeth and, within one week, can become so hard that you can no longer remove it on your own. As a result, the surrounding gums can become red and puffy and distract you from having a beautiful smile,” explains Dr. Lazare. Dr. Lazare warns that buildup can have a more serious impact, especially if left untreated for too long. “The bacteria in dental plaque make you twice as susceptible for developing heart disease.” Recommendation: According to Dr. Lazare, it’s critical for everyone to brush their teeth at least twice per day for two minutes per session with a soft-bristled brush, preferably electronic (this one from Oral-B has a five-star rating). “Brush first in the morning after breakfast so you leave your home with a clean mouth, and then again before going to sleep,” Dr. Lazare suggests. He considers the nighttime brush most critical. “When you sleep, there is less saliva to bathe the teeth, leaving you more susceptible to developing cavities from the acids that are trying to break down the left over food debris.” Explanation: According to experts, flossing should be a natural (make that non-negotiable) part of any oral hygiene routine. “Brushing without flossing is like taking a shower and washing everything but your armpits,” cautions Dr. Lazare. “All surfaces of your teeth need to be cleaned, especially those areas between the teeth that can trap food and bacteria and lead to tooth decay and gum disease.” Recommendation: Dr. Lazare prescribes flossing at least once per day to remove food and plaque from areas your toothbrush can’t reach, preferably after you brush and before you go to sleep. “The right technique is critical to ensure you do not traumatize your gums. Ask your dental care provider for guidance.” Explanation: The tongue’s velcro-like surface makes it adept at trapping and harboring the anaerobic bacteria and volatile sulfur compounds that give off an odor, says Dr. Lazare. “It has been found that 90 percent of halitosis originates from the mouth, with 80 percent coming from the posterior third of the tongue. This area of the tongue cannot be cleaned with a toothbrush and rinses only mask the issue at best,” he explains. Recommendation: Dr. Lazare points out that brushing the posterior of the tongue with a regular toothbrush can stimulate an uncomfortable gag reflex. “The only definite way to remove those volatile sulfur compounds that cause bad breath is to scrape the tongue with a tongue scraper that is designed to reach that area specifically,” he says. Just like with floss, you’ll want to do this post-brush and, if limiting to once per day, ideally pre-slumber. Explanation: Considering borrowing a brush from a S.O. or friend after an impromptu stay-over? Opt for the mouthwash or tolerate the morning breath instead. “We use toothbrushes to clean away bacteria and food debris from the crevices of our teeth and oral tissues. Sharing a toothbrush would transmit a host of infectious microorganisms to the new user and could lead to serious illness,” explains Dr. Kunen. Recommendation: Dr. Kunen suggests keeping a travel toothbrush on hand for emergencies, along with some spares at home for unexpected guests who may be in need. This pack from Colgate ($4; amazon.com) features a range of different colors for helping to avoid mix-ups. Explanation: While you should aim to shower for your body every day, experts say you can get away with—and even benefit from—cleansing hair less often. “Washing your hair daily can strip your scalp and strands of natural oils. These oils are produced to nurture and protect, and ridding them too often can leave strands dry, limp and lifeless,” cautions Irving Ramirez, a hairstylist in New York. Martha Lynn Kale, owner and operator of the Mirror Mirror hair salon in Texas, also points out that hair is most vulnerable when wet. “Then you factor in the brushing, blow-drying and heat-styling tools that typically correspond with washing, which can further damage hair!” Recommendation: As a general rule, experts say you should aim to wash hair once to twice per week. “Use a clarifying shampoo with a nourishing conditioner and properly style your hair—the effort will pay off and save you time on other days!” says Kale. If you work out often during the week and feel the need to wash more often, Ramirez recommends rinsing hair out with water and just using a conditioner. “If you absolutely must use shampoo, opt for a baby or sulfate-free formula, as they tend to be gentler.” If you are prone to dandruff (seborrheic dermatitis), Dr. King says you’ll want to find a balance that works for you, as washing hair less frequently could potentially contribute to a flare. “This may be because of yeast on the scalp that builds up and contributes to inflammation.” See your dermatologist for a recommendation that suits your individual condition and needs. Explanation: Dr. Desai says styling products don’t tend to penetrate deep enough into the scalp to damage the hair follicle, but that using products with harmful ingredients can damage the hair itself. “Alcohol-containing gels and mousses can have a drying effect, which will leave the hair more prone to breakage and damage over time. Alternatively, the overuse of greasy or oily products without proper washing can cause breakouts on the scalp and forehead,” Dr. Desai explains. Dr. Desai considers an excess of styling tools and accessories (such as tight ponytail holders) even more worrisome “as they can cause hair loss due to breakage along the hair shaft and damage to the actual hair follicles.” Recommendation: Try to limit the amount of products you use on a regular basis, prioritizing lightweight formulas that are designed for your hair type to avoid heaviness and buildup, and “lean on styling tricks to help do the heavy lifting (such as creating volume or smoothing out frizz),” says Kale. This is another place where Dr. Desai says a gentle or, if wearing more or washing less, clarifying shampoo can come in hand. “You should also condition after you shampoo, as this will leave your hair smoother and softer and help to reduce breakage.” Lastly, you’ll want to minimize the amount of harsh chemicals and heat. “Don’t be afraid of buildup from heat protectants, as they coat the hair cuticles and can help maintain hair health overall,” says Desai. Explanation: While sharing products that have uncompromised formulas (such as spray gels and mousses) are generally low risk, Kallie Henskens, a hairstylist at the Golden Soul Salon in Austin, considers sharing hair brushes a big no. “The same goes for sharing combs and accessories, which can leave one vulnerable to additional bacteria, dandruff and psoriasis,” she explains. When involving high heat, Henskens would place styling tools a bit lower in terms of grossness level. “A good temperature usually ranges anywhere from 200 to 450 degrees, which tends to burn off any bacteria,” she says. Recommendation: According to Henskens, you should avoid sharing regular hair tools and accessories unless you can ensure they’ve been properly disinfected. “While many salons take sanitization seriously, you can also ask them about their procedures or explore bringing your own brush, etc. as comfortable.”