Before washing a pyjama set, do you rewear it for a few days? A week? Only one night? Of course, the answer depends on the person. But is there a right or wrong way to do it?

As an “every couple days” person, I had to do some amateur sleuthing — so obviously, I ran to the poll button on Instagram and X (formerly known as Twitter).

Between the two apps, my poll received 122 votes (so, not the biggest sample size, I admit). Here are the results:

• About 13% of people never rewear their pyjamas before washing them. (In other words, they change daily.)
• About 60% change their pyjamas every few days.
• About 22% change their pyjama set every week.
• About 5% wear a pyjama set for over a week before washing.

I wanted to hear the reasoning along the whole spectrum, so I asked some folks. 

Jarone Ashkenazi, a 35-year-old construction manager in Los Angeles, washes his pyjamas with his sheets weekly. “Call it a habit or a superstition, but I like having new clothes to go with washing new bedding,” he said, noting he’s done this for as long as he can remember. 

But for Melissa Lockhart, the New York-based founder of the sleepwear brand Melda Molda, daily PJ changes help her feel her best.

“I put on a fresh pair of pyjamas every night because I believe getting dressed for bed is as significant as dressing for work, a date or a party,” she said. “Showering and slipping into clean pyjamas marks the start of my nighttime routine and serves as a clear signal to transition from work mode to relaxation mode — just as showering, putting on makeup and a clean outfit starts my workday.”

So how often do a dermatologist and sleep experts suggest you wash your pyjamas between wears? 

Factors that dictate how often you should wash your pyjamas

The American Cleaning Institute and the experts consulted here generally recommend rewearing pyjamas no longer than a few days in a row, for reasons we’ll get into below.

“If you wore them only in a clean, cool environment, you could probably wear them three to four times before washing them,” said Dr. Andrew Colsky, the founder of National Sleep Center, who’s known as the “Sleep Science Guy.” 

In some scenarios, pyjamas can get dirty fairly quickly, in which case more frequent washing is in your best interest.

“It’s more important to think about several factors before,” said Dr. Daniella Marchetti, a PSYPACT-certified sleep specialist and licensed clinical psychologist.

If any of the following ring true, you’ll probably want to throw your pyjamas in the laundry hamper after wearing them once or twice, these experts say:

• You didn’t shower
• You experience night sweats, sweat in the pyjamas at other times, or sleep in a warm environment 
• You don’t wear underwear during the day or at night
• You apply lotion or other skin care products before bed
• You’ve sat on public chairs in your pyjamas, or your PJ pants have dragged on the ground (basically, situations in which the fabric comes into contact with germs and dirt)
• The pyjamas come into contact with sensitive skin, such as underwear, socks and leggings
• The pyjamas are made with synthetic fibres

To explain that last point: “Fabrics like cotton or flannel absorb natural oils, which means that oils, dirt and bacteria may be trapped and would need to be washed more frequently,” said Dr. Anna Chacon, a board-certified dermatologist and founder of Miami Derm. 

On the other hand, she said, silk and satin fabrics are usually better about not getting greasy from night sweats, because they’re breathable and less absorbent. 

Some of those bulleted factors may affect your pyjama bottoms more than your tops, or vice versa. For example, going commando at night doesn’t affect your shirt as much (if at all). Or maybe you tend to sweat more from your armpits than your legs. Should you just rewear the cleaner item?

“A good rule of thumb is that if you plan to wash one, you should just wash both,” Colsky advised. This was also Chacon’s view.

Some situations aren’t so clear, though, like working from home in your pyjamas.

If “working from home” means “not leaving the house” for you, you’re avoiding environmental factors, which helps. “A good rule of thumb is if you are leaving the house in your pyjamas (or really any clothing), it’s best to wash the clothes before you wear them again,” Chacon said. 

At the same time, wearing that same set of PJs from last night to tonight could cause a buildup of oils, sweat and spills, she said. In that case, working from home in pyjamas means you may want to rewear them fewer times.

But back to that earlier list: More frequent washes are important in these situations, Colsky said, because of the risk of sweat and oil buildup, dirt accumulation and bodily secretions. 

The negative side effects of rewearing your pyjamas too many times

As mentioned, a lot of gunk can get stuck to your pyjamas — and your body — if you don’t wash them enough. Aside from being a gross thought, what are the potential harms?

“Factors like sweat, skin oils and dead skin cells create the perfect environment for bacterial growth, which can lead to infections, skin sensitivity issues, acne, clogged pores, rashes, irritation or even allergic reactions,” Colsky said. “I definitely do not recommend [wearing] pyjamas too many days in a row.”

Plus, if germs get on the fabric, rewearing that article of clothing can make you more likely to get sick, Chacon said. 

Last but not least, even your sleep can be affected. 

“Night sweats can create sleep maintenance issues, so sleeping in dry-wicking activewear or pyjamas formulated for night sweats will help with overall sleep,” Marchetti said.