(NEXSTAR) — Showering on a daily basis – whether in the morning or at night – is generally enough to keep you clean and healthy, according to top dermatologists.

Your opinionated friends, however, might call you a filthy pig if you choose one over the other.

“If you ask a hundred different doctors, you’re going to get a hundred different answers,” Alok Vij, M.D., a dermatologist at the Cleveland Clinic, told Nexstar. “But it’s more a matter of personal preference, in many cases.”

Vij, however, said he believes there’s a “definitive” answer to the debate concerning morning vs. evening showers in regards to general hygiene, but warned that his answer comes with several qualifiers.

“I think it’s important to shower before bed if you’ve gotten dirty or visibly soiled, or if you’ve applied some kind of chemical spray — a bug repellent, sunscreen — anything with fragrances or chemical additives,” Vij said. “If you haven’t, if you’ve been living a clean life and you didn’t work out … there’s not necessarily a better time to shower.”

Dawn Marie Davis, M.D., with the dermatology department at the Mayo Clinic, generally agrees that showers should come after skin becomes “dirty, irritated or sweaty.”

“Some patients with sensitive skin, and particularly those with atopic dermatitis (eczema) find that showering or bathing at bedtime is helpful for removing irritants from the skin and also assists with sleep hygiene,” Davis noted in an emailed statement to Nexstar.

Vij added that patients with eczema or psoriasis might benefit from a nighttime shower to soothe any itchy skin before topical medications are applied. (Topical medications, Vij said, are generally safe to leave on the body while sleeping, as are gentle moisturizers.)

But lest anyone think that showering before bed keeps their sheets completely clean, top dermatologists have some bad news: Your bed is likely full of dead skin cells, and probably sweat, no matter what time of day you shower.

Skin is constantly shedding dead cells, with the average human losing around half a billion every day, according to a dermatologist-reviewed article at WebMD. That works out to a gram or more per night, Vij said.

You also sweat out about 26 gallons of fluid per year in your sleep alone. And while Vij said the sweat itself is sterile, it often mixes with oils or proteins on the outer layer of epidermis, which can create a breeding ground for bacteria.

“[Those skin cells and bacteria] are going to sit there until you wash your sheets,” said Vij, who recommended changing sheets at least once every two weeks, or once a week for those who often sweat in their sleep, or have easily irritated skin.

Pillows, too, should be washed at least once every six months, he added.

As researchers note, there’s also another major factor that determines when a person might prefer to shower, and it has to do with their waking or sleep rituals.

Many proponents of morning showers have said that bathing earlier in the day wakes them up, and surveys appear to back up their claims. Morning-showerers who participated in a 2022 survey conducted by the Sleep Foundation overwhelmingly (81%) felt the practice jump-started their day. And in a separate, self-reported 2023 survey, a slightly larger percentage of participants who showered in the morning said they felt more productive at work and more energetic when compared to the responses from nighttime bathers.  

Researchers at the University of Texas at Austin, meanwhile, had analyzed data from over a dozen sleep studies and concluded that a warm bath or shower, at least an hour before bed, helps the body regulate temperature and fall asleep faster at bedtime.

“It’s all about making yourself feel as good as possible when you’re presenting yourself to the world,” said Vij, who also acknowledged the role that a good night’s sleep plays in a person’s outward demeanor. “If [that means] a shower in the morning, or … you feel better getting clean when you get into bed, by all means do it.”

As for Vij himself? He more of a morning-shower guy.

“I feel like I don’t truly wake up until I’ve hopped in the shower,” he told Nexstar. “But my wife is a night shower person. And my kids would rather never shower if they could.”