With a mini-heatwave forecast to hit parts of the UK, many Brits may soon be tempted to go to bed with wet hair in an attempt to keep cool. But a hair specialist has issued a warning that this habit can actually wreak havoc on your locks from the inside out.
Hair transplant expert Yannis Giantzides, CEO of Manchester Hair Transplant Clinic, has revealed that wet hair left to air-dry actually suffers worse internal damage than properly controlled heat-drying.
This is because hair that stays wet too long faces serious damage to its cell membrane complex (CMC), which is what holds hair fibres together and gives it strength.
The revelation turns everything we thought we knew about hair care upside down.
Giantzides explained: “It is widely assumed that natural is always better, but when it comes to drying your hair, that’s not necessarily the case.
“Hair is most vulnerable when it’s wet, because water causes the hair to swell, and this puts pressure on the protective outer layer.
“When hair stays wet for too long, the CMC can become compromised. This leads to weaker, more fragile hair which can be more prone to breakage and split ends.”
A study published in the Annals of Dermatology found that only naturally dried hair showed signs of CMC damage, while hair dried with controlled heat kept better structural integrity. Hairdryers might cause minor surface damage to the cuticle, but air-drying was the only method that harmed the deeper CMC layer.
With the growing popularity of reducing heat used on hair, such as using heatless curlers, which accounts for over 314,000 posts on TikTok (#heatlesscurls) and other methods of styling, this advice seems at odds with the craze. However, the experts highlight that it is not just better to use heat, but heat in a controlled way that is healthiest for your hair.
Specialists at Manchester Hair Transplant Clinic recommend the use of a hair dryer on medium heat, kept about 15 cm from your hair while moving it constantly around different sections. This evaporates water quickly without exposing any single spot to too much heat.
For anyone worried about heat damage, Giantzides offers a simple fix:
“Gently remove excess water with a microfibre towel first, using a blotting technique, then use a heat protectant spray before blow-drying at a medium temperature setting.”
Specifically, Brits are warned not to go to bed with wet hair:
“Sleeping with wet hair increases friction against your pillow, which can lead to breakage and tangles. In some cases, it can even lead to fungal growth on your scalp,” Giantzides explained.
Continuing, he also noted that people with dyed or chemically treated hair risk the most damage from air-drying. He commented. “These treatments already compromise the hair’s protective layer, making it more vulnerable when wet. For these hair types, quick, gentle drying is especially important.”
While blow-drying works best for most hair types, some exceptions exist. Those with natural curls might benefit from careful air drying during the day. Strong airflow from blow dryers can disrupt curl patterns, crack the curl structure and create split ends.
If you don’t want to give up air-drying, Giantzides says to cut the time that hair is wet as much as possible.
To do this, use a microfibre towel to squeeze out a lot of the water straight after washing, then apply quality leave-in products that help protect your hair’s structure. Just make sure any air-drying happens during daylight hours, never overnight.
