Nonenal: the "older person smell" explained, and how to wash it away

Most people notice it on someone else before they notice it on themselves: a faint, slightly waxy, "old book" kind of smell that hangs around even after a shower. It has a name, nonenal, and it is one of the most common and least talked about changes that come with getting older. This guide explains what it is, why an ordinary bar of soap does so little about it, and what actually helps.

What is nonenal?

Nonenal (2-nonenal) is a naturally occurring compound that forms on the skin when certain fatty acids in skin oil, mainly omega-7 acids such as palmitoleic acid, are broken down by oxygen. Japanese researchers first described it in 2001, which is why so much of what we know about it, and so many of the products designed around it, come from Japan.

From roughly the age of 40 the skin produces more of these fatty acids while its natural antioxidant defences slow down. The result is more nonenal on the skin's surface. It is not a sign of poor hygiene. People who shower every day still produce it.

What does it smell like?

People describe it as greasy, grassy, slightly musty or like old paper or candle wax. It is mild rather than sharp, which is exactly why it is easy to miss on yourself: the nose tunes out familiar smells, and this one builds up slowly. It tends to sit on the skin around the chest, back, neck and behind the ears, and it transfers easily to collars, pillowcases and bedding.

Why ordinary soap does not shift it

Nonenal is not water soluble. It sits inside the oily film on the skin, so a quick rinse or a light lather washes off the fresh sweat on top and leaves the oily layer, and the smell, behind. Strong deodorants and perfumes cover it for a few hours, and stripping soaps can make skin dry and tight without dealing with the cause.

What is needed is a wash that lifts the oily residue itself, gently enough to use every day.

Why persimmon?

Japanese persimmon (kaki) is rich in tannins, natural plant compounds that bind to odour-carrying molecules and help wash them away with the water. Persimmon tannin has been used in Japan for centuries, on everything from paper to fabric, precisely because it neutralises smells rather than masking them. In a modern soap it does two useful things at once: it helps break down the oily film where nonenal sits, and it helps carry the odour molecules off the skin.

Our KAKIORA Japanese persimmon soap pairs persimmon extract with a creamy palm-oil base, coconut oil, hyaluronic acid and hydrolysed collagen, so it cleans the residue away without leaving mature skin feeling stripped.

A simple daily routine that works

1. Wash the right places. Chest, back, the back of the neck, behind the ears and under the arms. Lather with your hands or a soft cloth and give it 20 to 30 seconds before rinsing.
2. Use it daily. Nonenal forms continuously, so results come from routine rather than an occasional deep clean. Most people notice a difference within the first few days.
3. Change what touches your skin. Pillowcases twice a week, fresh collars, and air bedding in the morning. Nonenal builds up in fabric.
4. Look after the skin barrier. Dry, over-washed skin produces more oil. A gentle, moisturising wash beats a harsh one.
5. Everyday basics help too. Good sleep, less alcohol and plenty of water all reduce how much oxidised oil ends up on the skin.

Is it a health problem?

No. Nonenal is a normal part of skin chemistry and is not a disease or a sign of one. If you notice a sudden change in body odour that is very different from this, that is worth mentioning to a doctor, but the everyday "older skin" smell is simply something to wash properly.

Frequently asked questions

Does nonenal affect men and women equally? Yes. It increases with age in both. Men often notice it earlier because they tend to produce more skin oil.

How long does a bar of KAKIORA last? Used once a day on the odour-prone areas, one bar lasts around four to five weeks.

Can I use it on my face? It is a gentle bar, but we designed it for the body. If you use it on your face, avoid the eye area and follow with your usual moisturiser.

Ready to try it? Choose your KAKIORA pack. Every order is covered by our 30-day money-back promise.