There is a smell that a person does not notice in themselves. That is why others rarely mention it directly. It does not come from the armpits, and deodorant has no effect on it. The source of the smell is in several areas of the body that most people never wash deliberately.

Below are 12 rules. Six of them can be applied tonight, and one takes 10 seconds. The material is based on published research. Where the data is insufficient, this is stated directly.

Rule 1. Body odor is three different smells

In Russian, "body odor" refers to a single concept. In Japanese, different terms exist for different stages of life, because the smell changes with age.

Deodorants and clean socks help only against the first type of smell. If you fight the third type with remedies for the first, there will be no result: you are treating the wrong place.

Rule 2. Know Where the Source Is

In 1999, researchers at the Japanese cosmetics company Shiseido were searching for the cause of age-related body odor. They discovered a substance called 2-nonenal. When they studied people aged 20 to 70, this substance was found only in people over 40. There was no difference between men and women.

Nonenal is formed from skin oil (sebum). With age, the composition of the skin's lipids changes. When this oil comes into contact with air, it slowly oxidizes, and nonenal is formed. The researchers themselves described the smell as slightly greasy and grassy, reminiscent of old books or candle wax.

The substance is released mainly from four areas:

• the back of the neck;
• the area behind the ears;
• the chest;
• the upper back.

These areas contain the greatest number of sebaceous glands. They are difficult to assess on your own, because a person cannot smell their own odor in these places.

A 10-second test. Press your finger behind your ear and smell it. The intensity of the smell, strong, weak, or absent, will show which area needs attention.

Most people carefully wash their face and armpits, but water on the back of the neck and behind the ears usually just runs over them. Starting this evening, these four areas should be washed deliberately, every day, with your hands or a soft cloth.

Rule 3. Hot Water Works Against You

A hot shower feels like a more thorough cleanse. In fact, it strips the skin's protective lipid layer. In response, the skin starts producing more sebum. Within a few hours there is more of it than after a shower with warm water. Because nonenal forms precisely from sebum, a closed loop arises: the hotter the water, the more raw material for odor the skin produces by evening.

Recommendations:

• Use warm water, not hot. The temperature should be such that you can dip your hand in without flinching.
• Don't linger in the shower. A long hot shower dries out the skin more than a short warm one.
• Use a soft washcloth to wash your back. In Japan, people traditionally scrub their backs with a long, narrow towel, and stores still sell stiff nylon scrubbers. After 40, the skin becomes thinner and drier. Daily intensive friction leaves redness and a feeling of tightness. The goal is to remove sebum, not the top layer of skin.

About soap. It is claimed that ordinary soap doesn't remove nonenal and that a special Japanese product is needed. Shiseido does not make this claim. The company's main recommendation is to wash properly and rinse off sebum. Japanese pharmacies have dedicated shelves of products for kareishu, many of which contain persimmon extract (kakishibu). Such products exist, and many people use them. However, almost all studies of their effectiveness are conducted by the manufacturers of these products.

It is enough to use a gel that already suits you. The key is to let the lather sit on the four zones for 30 seconds before rinsing. Contact time with the skin matters more than the brand.

Rule 4. Shower in the Evening, Not in the Morning

In Japan, almost everyone showers before bed. The reason is not tradition but calculation. An evening shower removes the sweat and skin oil that have built up over the day. After that, a person gets into bed for 8 hours. If you only shower in the morning, you sleep all night in the previous day's skin oil and rub it into your pillowcase. In the morning you wash off what has oxidized overnight, but the pillowcase stays dirty. The difference is significant, and the cost is zero.

If a morning shower is a deeply ingrained habit, the compromise is this: in the evening, at least cleanse four areas (the back of the neck, behind the ears, the chest, and the upper back). This takes two minutes at the sink.

The second part of the rule, which is often skipped: thorough drying. We dry our face and hands but leave the back of the neck, the area behind the ears, and the areas under the hair damp. Warm, damp skin is the most favorable environment for bacteria. After showering, these areas should be dried separately and thoroughly. A convenient method is to run a hair dryer over the back of the neck for a few seconds on the cool setting. It feels pleasant, and the skin dries completely.

Rule 5. Diet: What Is Confirmed and What Is Not

Accuracy matters most here, because this is the area where promises are made most often.

The confirmed part. Nonenal forms through the oxidation of skin lipids, so diet in principle affects the process. Heavy fried food, excess alcohol, and smoking intensify oxidative processes in the body.

The unverified part. No product can eliminate this odor. Supplements, green powders, and teas are sold that supposedly flush out nonenal. There is no research confirming such an effect.

A realistic formulation is this: diet may slightly change the baseline level of odor. Treating the four zones produces results as early as tonight. The order of action should be this: first what works reliably, then what may help to a minor degree, not the other way around, as those who sell a jar of supplements suggest.

A separate note on alcohol. Alcohol creates an odor that is not related to the skin. It is exhaled with the breath and lasts for several hours. It is often confused with age-related body odor. As a result, people wash intensively, even though the source is elsewhere.

Rule 6. The Towel That Gives the Smell Back

The familiar sour smell of laundry that has dried too slowly is linked to bacteria. In 2012, researchers at the Japanese company Kao identified the main bacterium responsible for it: Moraxella.

If bacteria live in a bath towel, a person transfers them every evening onto freshly washed skin. All the previous work is then undone.

The researchers also studied the role of sunlight. On its own, it does not kill this bacterium well. What matters is not the light but how long the fabric stays damp. This leads to three conclusions:

1. The towel must dry quickly. It should be hung spread out, not folded in half over a hook. Thin terry cloth dries faster than thick. In Japanese homes, towels are usually quite thin.
2. Wash the towel more often than seems necessary. A survey in Japan found that about half of people wash their bath towel after every use.
3. If a towel smells right after use, washing will no longer save it. Such a towel needs to be replaced.

Rule 7. Bedding That Outlasts the Smell

People usually think about the pillowcase but forget about everything else. Every night, a pillowcase absorbs skin oil from the neck and head. Changing it once a week is not enough. It should be changed every 2–3 days. This is the cheapest and most noticeable change on the list.

Fabric matters too. In a 2014 study, after intense training, polyester T-shirts smelled stronger and more unpleasant than cotton ones. The layer that touches your skin at night is better chosen from cotton. But what matters more is what lies beneath the pillowcase. Over the years, the pillow absorbs everything that passes through the pillowcase.

Pillows have an expiration date. Synthetic pillows should be replaced roughly every 2 years. Down pillows are replaced less often, but they also need to be replaced eventually. If a pillow remembers the last decade, no fresh pillowcases will hide it.

A simple test. In the morning, before airing out the bed, take off the pillowcase and sniff the pillow itself. The answer will be immediate.

The same applies to the duvet and the mattress. Duvets need to be washed or at least aired out regularly. In Japan, people do this literally every sunny week, and futons are hung over balconies all across the country. A mattress should be protected with a removable cover that can be washed.

Rule 8. The Fabric That Rubs Against the Neck

Scent doesn't stay only on the skin. It transfers to fabric, which then gives it back. Think about what touches the back of your neck every day.

• Shirt or blouse collars are washed along with the garment. That's normal.
• Coat collars usually aren't washed at all.
• Scarves worn all winter often aren't washed until spring.
• Hoods.
• Car headrests. They touch the neck on every trip, for years, and are almost never cleaned. Wipe them with a damp cloth once a week. It takes one minute.

The car has another trap. The driver gets used to the cabin smell, but a passenger notices it right away.

Rule for coats and scarves: if an item is worn all winter and sits against the neck, it should be washed or dry-cleaned at least once per season, not only when visible dirt appears. The item may not look dirty, but it will absorb odor regardless.

Rule 9. Wash the Scalp, Not Just the Hair

In Japan, the scalp is considered skin and is washed as a separate procedure. Usually people wash their hair, and that is not the same thing. The scalp has many sebaceous glands, and it spends all day under a warm layer of hair. It is precisely this combination that creates a second type of odor, greasy, which appears earlier than age-related odor.

If you quickly lather your hair, the product does not reach the scalp.

The right way: use your fingers, not your nails. Massage the scalp for at least a minute, moving from the forehead toward the crown and finishing at the back of the head. The back of the head borders the back of the neck, that is, the area from the second rule.

Two habits that help:

1. Wash your hair in the evening and let the scalp dry completely before bed. A damp scalp on the pillow creates an environment that should be avoided.
2. Use dry shampoo carefully. It refreshes the hair but does not remove the oil, only covers it. It is an auxiliary product, but not a substitute for washing.

Rule 10. How to Check Yourself if Your Nose Has Gotten Used to Your Own Smell

Usually, in such conversations, the phrase "you can't smell yourself" comes up and the topic is closed. However, you can check yourself. There are three effective ways.

1. The fastest: check the fabric, not the skin. Sniff the collar of a shirt you wore all day, a pillowcase from the morning, a scarf. Fabric holds onto what your nose has already adapted to on the skin.
2. Step out of the house for 20 minutes. Just take a walk and come back. In the first few seconds after returning, your nose picks up smells again. This method works for both an apartment and a car.
3. The most honest and the most difficult: ask the right way. Almost nobody will honestly answer the question "Do I smell bad?" Ask differently: "Could you check this for me?" and ask them to sniff your collar or pillow. People find it easier to honestly evaluate an object than a person.

The mechanism of adaptation. If a smell is constantly present, sensitivity to it decreases in about a couple of weeks. That is why your own sofa, bedroom, and car become unnoticeable to the owner, whereas a guest notices the smell first thing.

Rule 11. In Winter, Smell Is More Noticeable Than in Summer

This sounds unexpected. In summer it is hot, and people sweat more. However, age-related odor works differently, and winter intensifies it for three reasons at once.

1. In winter, people wear the same clothes (one coat, one scarf, one sweater) day after day, for weeks. In summer, clothes are changed daily and sent to the laundry.
2. In winter, rooms are rarely aired out. Windows are kept closed, heating dries the air, and odors accumulate in the apartment, settling on textiles, curtains, pillows, and carpets.
3. Heating and hot showers together strongly dry out the skin. Dry skin starts producing more sebum in an attempt to protect itself. More sebum means more raw material for nonenal.

What to do:

• Air out the room every day for at least 10 minutes, even in frost. In Japan, people do this in winter too.
• Wash your scarf and coat collar in the middle of the season, not only in spring.
• Moisturize your body after showering. According to the author, this is not a cosmetic whim but a way to reduce excessive sebum production.

Rule 12. Eliminate the Source, Don't Mask It

This is the main distinction of the approach and deserves special attention. The usual reaction to a smell is to cover it with a stronger one: perfume, spray, a car air freshener. The Japanese approach is the opposite: if there is a smell, its cause is eliminated.

The Japanese language has the word kaigai (literally "harm from fragrance"). It refers to a situation where someone's perfume is so strong that it bothers the people around them. This is discussed openly, including at work.

Mixing of smells. When a pleasant fragrance combines with body odor, the latter does not disappear. They form a third, new smell. A person no longer smells of perfume, but of perfume plus themselves.

It is often claimed without evidence that only citrus scents work against age-related body odor. The author found no research that confirms this.

A logical order of actions:

1. Wash with a product that is unscented or has a mild fragrance.
2. If you like a perfume, apply it sparingly to clean skin as a supplement, not as a means of masking.

Why it is important to talk about this. In Japan there is the word sumehara, a contraction of "smell harassment." It is used openly, including at work. A manager can calmly say this to an employee in private, and it is considered a work task to be solved, not an insult.

There is no such word in Russian, and there is no tactful way to say it. That is why the people closest to you have probably already noticed the smell and decided that silence would be kinder.

Summary

It's not about poor hygiene; it's about chemistry. Sebum changes with age, and nonenal builds up on four small areas of skin that no one was ever taught to wash.

A reassuring fact. In 2012, researchers at the American Monell Chemical Senses Center asked people to rate the body odor of different age groups. The odor of the oldest group was rated as less intense and less unpleasant than that of the young participants. This process affects everyone, and there is nothing to be ashamed of. All it takes is consistency.

What to do tonight:

1. Wash with warm, but not hot, water.
2. Thoroughly clean the back of the neck, the area behind the ears, the chest, and the upper back, leaving the lather on for half a minute.
3. Massage the scalp, finishing at the back of the head.
4. Dry these areas thoroughly.
5. Use a dry towel and a clean pillowcase, and air out the bedroom for 10 minutes before bed.

The essence of the Japanese approach comes down to three principles: eliminate rather than mask, act gently rather than harshly, and do it every day rather than occasionally.