Second-hand shopping can be a thrill. You spot a “pre-owned” treasure, you imagine the savings, you pat yourself on the back for being a savvy deal-hunter. But hold on: not every bargain is a wise buy. According to consumer-advice sources such as AARP and others, some items carry hidden risks when bought used — hygiene problems, safety failures, missing standards, wear that’s invisible to the eye.
It’s not about being anti-thrift or ignoring vintage charm; it’s about knowing when you’re rolling the dice and whether you’re okay with the outcome. For example, you might buy a used appliance and discover later that its wiring is frayed and it’s a fire risk. Or pick up a used mattress and win a dust-mite rodeo for free. (Yes, that could happen.) So before you knock on the thrift-store door or click “Buy Now” on the second-hand site, keep in mind: some items just aren’t worth the gamble. Below are two examples of things you should almost always buy new — with a bit of humor, a bit of caution, and a firm shake of common sense.
Mattresses, Bedding & Pillows
Buying a mattress or bedding used is like adopting someone else’s sleep habits — and their dust mites, possible bedbugs, unknown stains, and mysterious history. The AARP article warns that you don’t know “who or what slept on it,” or whether it has allergens or pests. So, unless you’re ultra comfortable with mystery microbial roommates, go new.
Let’s be honest: you spend about a third of your life in bed. Do you really want someone else’s history in your restful zone? Probably not. A new mattress may cost more up front, but it spares you the uncertainty — and maybe the unseen hitchhikers. Trust your back, trust your nose, and trust your peace of mind: buy that mattress fresh.
Helmets & Safety Gear
When it comes to helmets (for biking, skiing, or motorcycling), buying used is playing with fire — figuratively and literally. AARP notes that a helmet is designed for one serious impact; once it’s done its job, or even might have done it, its protective value is compromised. You also can’t always tell if it’s been dropped, recalled, or damaged.
So yes — that shiny second-hand helmet might look cool and cost less, but if you ever hit the deck, you’ll want the assurance that your gear hasn’t already taken a dive. Safety gear isn’t where you half-save. Buy new, keep the certifications, and feel confident knowing your head protection hasn’t already been put to the test.
Car Seats
A used car seat might look perfectly fine, but when it comes to safety equipment for your child, “looks fine” doesn’t cut it. The National Highway Traffic Safety Administration and consumer groups like AARP strongly advise against buying used car seats. You don’t know whether it’s been in an accident, if it’s past its expiration date (yes, car seats expire), or if it’s missing key components. Manufacturers also frequently update safety standards, meaning an older seat might not meet current regulations.
Even a small, unseen crack could mean the difference between protection and disaster. Sure, the thrift-store price tag is tempting, but saving $100 isn’t worth the risk. When it comes to protecting a child, you want a seat that’s fresh from the box, complete with its manual and registration card. Think of it as peace of mind on four wheels — not a gamble with a mystery past.
Laptops and Other Electronics
Used laptops can seem like a good idea, especially when the sticker price is slashed in half. The savings often come with hidden headaches. Battery life is one of the biggest issues — and batteries lose capacity over time, sometimes drastically. Software can be outdated, warranties are usually void, and you might even inherit someone else’s hardware problems.
Then there’s the security concern: you can’t always be sure what’s been installed on that machine before you bought it. A “factory reset” doesn’t always wipe everything clean. Unless the device is certified refurbished by a reputable brand or retailer, it’s a roll of the dice. Spending a little more upfront can save you hours of frustration — and possibly prevent a data disaster later.
Shoes
Buying used shoes might feel like an easy way to score high-end brands for cheap, but here’s the catch — shoes mold to the original owner’s foot shape. That means you’re inheriting someone else’s wear patterns, which can lead to poor support or even foot pain. Over time, the soles, insoles, and cushioning break down in ways you can’t always see.
And let’s be real — even a thorough cleaning can’t erase every bit of bacteria or fungus that’s settled in. Feet are one of the sweatiest parts of the body, so no matter how “lightly worn” the listing says, it’s still a bit of a gamble. Unless you’re buying something like formal shoes you’ll rarely wear, or collectible sneakers meant for display, you’re better off stepping into a brand-new pair.
Makeup and Skincare Products
Secondhand makeup might sound like a money-saver, especially when you see pricey brands going for half off online. But beauty experts and dermatologists alike say this is one of the worst ideas in the used market. Once makeup or skincare is opened, bacteria from the original user’s skin, eyes, or mouth can contaminate the product. Even if it “looks fine,” it could harbor microbes that cause rashes, eye infections, or cold sores. There’s no reliable way to sanitize a liquid foundation, lipstick, or mascara once it’s been used.
And there’s another catch: cosmetics expire faster than you might think. A product that’s been sitting in someone’s drawer for two years may look new but has long since broken down chemically. Buying used makeup is like using an old toothbrush from a stranger — just because it looks clean doesn’t mean it’s safe. When it comes to what goes on your face, splurge on new. Your skin will thank you.
Vacuum Cleaners
A used vacuum cleaner might seem like a practical buy — after all, it’s a cleaning tool. But as U.S. News points out, what looks like a good deal can quickly turn into a clog-filled nightmare. Old vacuums often lose suction power, come with worn belts or motors, and may be full of dust, pet dander, or mold spores. Replacing filters or repairing parts can cost as much as buying new.
And that’s assuming it even works properly once you get it home. Many older vacuums aren’t compatible with modern filters or replacement parts, especially off-brand models. Plus, no one wants to inherit years of someone else’s dirt. A new vacuum is an investment in both your cleanliness and your sanity. If you’re looking to save, buy during seasonal sales or go with a reputable refurbished unit direct from the manufacturer.
Tires
Used tires can be a disaster waiting to happen. Even if the tread looks decent, you can’t see internal damage, previous punctures, or signs of dry rot that could cause a blowout on the highway. The National Highway Traffic Safety Administration warns that tires older than six years may be unsafe regardless of appearance, since rubber naturally degrades over time. And yet, used tire dealers often skip checking the manufacture date stamped on the sidewall.
That’s not to say every used tire is bad — but unless you personally know where it’s been, it’s not worth the gamble. A tire might have survived an accident, been patched poorly, or been stored in extreme heat, weakening the structure. Saving a couple hundred dollars now could mean risking your life later. When it comes to tires, new is non-negotiable. You can’t put a price on staying in control at 70 miles per hour.
Baby Bottles and Pumps
Some baby items are safe to buy secondhand — but not bottles or breast pumps. The FDA specifically advises against reusing breast pumps unless they’re labeled as “multi-user” and come with new tubing and collection kits. Milk residue can linger inside even the tiniest crevices, allowing bacteria and mold to grow. The same goes for bottles and nipples — small scratches and worn areas can harbor germs that are impossible to fully sterilize.
For something that’s going directly into your baby’s mouth, “almost clean” isn’t good enough. AARP also warns that many used baby products have been subject to recalls or fail to meet current safety standards. When it comes to feeding gear, buy new, replace parts regularly, and follow manufacturer guidelines. It’s one of those cases where peace of mind far outweighs the cost.
Large Appliances
A used refrigerator, washer, or oven might seem like a big win for your wallet, but experts caution it can easily turn into a big headache. Wirecutter notes that appliances have a finite lifespan, and buying used often means you’re stepping in halfway through it. You may not know if it’s been repaired poorly, if parts are on the verge of failing, or if it meets current energy-efficiency standards.
Even if the seller swears it “works great,” there’s no guarantee it will keep doing so once you plug it in at home. Replacing compressors or control boards can cost hundreds, and warranties on secondhand units are rare. If you really want to save, look for scratch-and-dent discounts or certified refurbished models from the manufacturer. At least then, you’ll have a warranty to fall back on when your fridge decides it’s had enough of adulting.
Swimsuits and Undergarments
Some things just shouldn’t have a second life, and swimsuits or underwear top that list. Even after washing, these items can retain bacteria, yeast, and skin cells in the fabric — especially in areas that see, well, a lot of contact. Hygiene and health experts agree that it’s nearly impossible to fully sanitize elastic and stretch materials, which can trap moisture and harbor germs.
It’s not just about cleanliness, either. Elastic fibers break down with wear, meaning that secondhand swimsuit or bra won’t offer the support or fit you need. Plus, these items spend too much time close to your most sensitive skin to take any chances. If it’s been on someone else’s body, leave it behind. Some things are simply worth buying new — for both comfort and peace of mind.
Cookware and Nonstick Pans
Buying used cookware might seem thrifty, but it can also be risky — especially when it comes to nonstick pans. Over time, coatings degrade and can flake into food, particularly if the pan’s been scratched or overheated. Old or damaged nonstick surfaces may release harmful compounds when heated. Cast iron or stainless steel are more forgiving, but even those can hide cracks or warping.
Beyond safety, there’s practicality. Older cookware may not heat evenly, and replacements for worn handles or lids are hard to find. If you’re after a good deal, buy new during sales or opt for open-box sets from reliable retailers. The joy of cooking shouldn’t include guessing what might be coming off the pan and into your dinner.
Earbuds and Headphones
Used earbuds might look fine on the outside, but they’re among the most personal tech items you can own — and not in a good way. Earwax, skin oils, and bacteria can easily transfer from one person to another, and sanitizing them fully is next to impossible without damaging the electronics. Audiologists and tech reviewers at Wirecutter caution against buying used in-ear devices for exactly that reason.
Even over-ear headphones come with potential pitfalls: frayed cords, degraded padding, and worn speakers that affect sound quality. Plus, you never know if the previous owner’s “pet-free home” actually meant “cat slept on everything.” If you want to save, look for refurbished sets sold directly by the manufacturer. They’ll come cleaned, tested, and with a warranty — the trifecta of secondhand safety.
Pet Supplies
Used pet beds, toys, or litter boxes might seem harmless, but they can carry bacteria, fleas, or even lingering odors from their previous furry residents. Soft pet items like bedding and plush toys are especially problematic because they’re difficult to disinfect without ruining the material. And for animals with allergies or sensitive skin, even a trace of another pet’s dander can cause irritation.
Collars, leashes, and stainless-steel bowls can sometimes be cleaned thoroughly and reused, but when in doubt, go new — especially for anything involving food or sleep. Pets are family, after all, and they deserve a clean slate (and a clean bed). Besides, they won’t care if it came from the clearance rack as long as it smells new and squeaks properly.
