Shereene IdrissBoard Certified Derm, Founder and Chief Nerd

The Weird Science of “Old People Smell” & Why It Starts Earlier Than You Think 👵🏻

28 Sept 2026 · 2 min

Watch on YouTube

1:36

In this video Shereene Idriss explains the scientific basis for the stereotypical "old person smell." She describes how, as people age, the fats on the skin surface become more prone to oxidation, producing the volatile compound 2‑nonenal, which has a waxy, grassy, stale odor reminiscent of old bedsheets. This process can begin in the 40s. Idriss highlights that the area behind the ears is a prime odor trap because it is warm, oily, and hidden, allowing dead skin cells, sebum, and bacteria to accumulate. She clarifies that the odor is not caused by sweat, so deodorant is ineffective. To mitigate the smell, she recommends washing behind the ears each shower (using soap or shampoo and optionally a Q‑tip), and regularly laundering fabrics that contact the skin—face cloths, towels, pillowcases, and bedsheets—since they absorb the odor‑producing oils. The video frames anti‑aging as encompassing both appearance and scent.

Chapters

You stink, and as you get older, you smell even worse. But there is one spot on your body that can make the smell inherently worse. Scientists have discovered a molecule that contributes to that old person smell, and the stinky news for you is that it starts to appear as early as in your 40s. The molecule is called tuna needle, and the easiest way to think about this is to think of your bedsheets, because you sleep in your bed, your dead skin cells all over your bed, you sweat in your bed, and all of that reacts with oxygen. It starts to break down, which doesn't even smell like sweat, but it smells like old bedsheets. Stale. As we get older, the fats sitting on the surface of our skin become more prone to oxidation, and when they break down, they create 2-nonenal. And that is why, beginning as early as in your 40s, older people start to smell waxy, grassy, stale, slightly oily. And that's not a scent we're exactly rushing to bottle up. And the body part that makes the smell substantially worse? Behind your ears. It's a perfect odor trap. It is warm, it is oily, and it is tucked away, so Dead skin cells, sebum, and little bacteria can proliferate to their heart's little desires. Now that you know that you're gonna stink, what do we do about it? 1, wash behind your damn ears every single time that you shower. Get some soap, get some shampoo, and wash here. And by the way, this is probably the safest area that you can clean afterwards with a Q-tip, and it is oh so satisfying. 2, wash the fabrics that touch your skin regularly— face cloths, wash towels, pillowcases, bedsheets— because the skin oils and that odor compound transfers into the fabric, and that shit sticks around. And last, do not assume that deodorant is gonna work, 'cause this is not a sweat problem, it is a fat oxidation problem. So apparently anti-aging is not just about how you look, but it's also about how you smell.