Antiperspirants work better if they are applied at night

An antiperspirant ad campaign in the early 1900s dubbed body odor "B.O."

The product was marketed toward women and framed excessive sweating as a medical disorder that needed to be addressed with the product.

'Sweat dating' is a dating approach where partners specifically select by body odor

With dedicated events in major cities around the world, "sweat dating" offers people the chance to judge if a potential partner's smell is a match. Participants show up for an event, do calisthenics, wipe themselves with a cotton pad, and then place the smelly pad in a numbered jar for potential partners to sniff.

Americans spent $6.6 billion on body odor products in 2023

This high figure from Euromonitor, a research firm, suggests Americans spent more on deodorant than in any other country. Beyond deodorant, there's also growing interest in "whole body" deodorant designed to mask smells from various parts of the body beyond the armpit.

Sweat doesn't smell, but bacteria multiply in moist environments—and cause an odor

Body odor is associated with sweat, but odor actually arises from the bacteria that multiply in moist environments on your skin. Hormones, medications, food, and body hair can all affect body odor.

Skin wounds and burns heal fastest if they occur during the day

Skin cells responsible for healing wounds work more quickly during the daytime, underscoring that the timing of an injury greatly influences recovery time, according to 2017 research. Nighttime burns took an average of 11 days longer to heal than burns incurred during the day. (Some readers may experience a paywall.)

Wearing tick repellent, covering up, and performing tick checks are the best Lyme prevention

Spraying repellents onto your clothes—and reapplying them—or donning impregnated bug-repelling clothes can help keep ticks away. Effective sprays include DEET, picaridin, or permethrin. Bug spray applied to the body should be applied on top of sunscreen, and only after the sunscreen has dried.

Most people with East Asian ancestry are genetically predisposed to be less smelly

A gene variant found in 80%-95% of individuals with East Asian ancestry reduces armpit bacteria and related odors. People with this nonfunctioning ABCC11 gene variant lack a protein that transports molecules, including sweat, across cellular membranes, so their armpits are starved of sweat that bacteria may have metabolized to help them multiply.

Modern roll-on deodorant design was modeled on the ballpoint pen

Instead of a messy cream, which had been the norm in the 1940s, a new roll-on deodorant inspired by the easy flow of a ballpoint pen debuted in 1952.

Odor blockers use nonpolar oils to trap smelly polar molecules

In the case of feces, gut bacteria produce compounds such as skatole and hydrogen sulfide, which the brain registers as unpleasant. Because oils do not dissolve in water, they can be used to create a layer on the surface that prevents smelly compounds underwater from escaping into the air.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Poor sleep increases the risk of developing Alzheimer's

Brain imaging studies reveal poor sleep leads to production of amyloid beta proteins—molecules linked to Alzheimer’s—which are cleaned from the brain during high-quality sleep. These findings suggest conditions like sleep apnea and insomnia increase the risk of developing the disease.

Mineral and chemical sunscreens protect differently but both guard against UV damage

UVA rays age the skin, while UVB rays are more directly linked to skin cancer. Mineral sunscreens, with ingredients like zinc oxide, physically block rays, while chemical ones absorb UV and turn it into heat.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Olympians view sleep as a performance tool, prioritizing routine and environment

Elite athletes emphasize consistent sleep routines, dark and cool environments, the well-placed nap, and tools like eye masks, white noise machines, and supplements like melatonin (particularly for jet lag). This priority belies a core principle: recovery and performance are inseparable. Read more ways Olympians "sleepmaxx" here.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

There is a template for how to live a better, healthier day, and it includes a digital sunset

Science suggests that early-morning exercise, later-morning peak work or social time, consistent exercise, and a "digital sunset"—starting to turn down the lights in the evening and avoid screens—are important for circadian health.

Do sleep-tracking apps work?

Can technology help us sleep better? As wearables and apps promise to optimize our nights, this New York Times investigation reveals some troubling findings after columnist Brian Chen used a wearable for two weeks to track his sleep. He discovered that sleep trackers not only provide frequently questionable data but can also paradoxically worsen sleep problems by causing users to obsess over their metrics — a new condition researchers are calling ‘orthosomnia.’

Temperature and certain medications can also affect your circadian rhythms

Although light and dark have the largest influence on circadian rhythms, temperature, stress, and certain medications are among the factors that also play a role. Persistent trouble sleeping or staying asleep may signal it’s time to see your doctor to get a better sleep-wake schedule.

Forty to 110 minutes of deep sleep is recommended per night

Adults typically spend 10% to 20% of the night in deep sleep, also known as slow-wave sleep, with the rest of the night spent either in light sleep or REM states.

Home allergy tests don’t work well and experts urge caution

Doctors do not recommend at-home allergy test kits because their results may be inaccurate and confusing, and lead people to make lifestyle changes that are not warranted. Tests that require sending in a hair sample, for example, will not be helpful because hair does not have the relevant antibodies that blood testing would detect.

Explaining why salt should be used to season food early in the cooking process

Experiments involving the same dishes, with salt added at the start of cooking versus at the end, have been shown to yield drastically different taste outcomes because salt takes time to diffuse into foods, particularly vegetables, whose cells are surrounded by cellular membranes and walls. Salting at the end will produce a concentrated surface coating, rather than even seasoning.

Penicillin works by attacking the cell walls of bacteria

Penicillin targets bacteria at their weakest point—their cell walls. By blocking wall-building, it leaves microbes unable to survive, causing them to burst and die.

Nasal hairs, called vibrissae, help protect the body from particulate matter and other dirt

The nose structure plays a key role in filtering air before it enters our lungs and makes sure that the air temperature and humidity are also suitable for the body.

To ward off competition from Revlon, Estée Lauder launched Clinique—the first dermatologist-approved skincare line—in 1968

Clinique launched in 1968 as an entire product line, as opposed to just a single product, which was rare for cosmetics brands at the time. Clinique marked Estée Lauder's first venture into a younger, less luxury-oriented retail market.

Bupropion is the only antidepressant approved for the preventive treatment of SAD

Clinical trials showed a 44% reduction in risk for recurrence of SAD for those who took the drug compared to a placebo group. Bupropion is a norepinephrine–dopamine reuptake inhibitor, which increases dopamine (other common antidepressants, known as selective serotonin reuptake inhibitors, sometimes can suppress dopamine, but not always).

13 unconventional ways to stay cool during heat waves

While air conditioning is the default solution for many in a heat wave, it can get expensive while requiring the consumption of fossil fuel energy. So, how else can you stay cool during a heat wave? This list compiles some practical, at times quirky, suggestions, including an ice-pack-filled aubergine hat.

Cities and parks often work to prevent graffiti

Although some call it art, many see it as an eyesore and try to prevent it through prohibitive designs, lighting, and vandal-proofed coatings that make spray paint easier to remove. This guide from the Project for Public Spaces outlines some of those strategies and more.

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak each year.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Cultural norms about how to handle the bodies of loved ones in communities in West Africa have hampered Ebola responses.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

The Brothers Grimm were lawyers before they were storytellers, but became interested in fairy tales as they began investigating how rules and customs had been passed down through cultures.