There are lots of factors that can stop your hair from growing as long and luscious as you'd like, from overusing heated styling tools like straighteners and curlers, to dryness caused by the environment and, of course, split ends. But how many of us have thought about the amount of sleep we're getting and whether a lack of it can impact our hair?
The findings are pretty negative. According to Kerluxe hair restoration consultant Dr Sajjad Khan, poor sleep not only affects our skin and energy levels but the overall health of our hair. "Quality sleep is needed for adequate protein synthesis of the hair as well as the release of growth hormones and enzymes needed for healthy hair," Dr Khan explained. "In regards to your hormones, you’ll find that when you don’t get enough sleep, the production of melatonin (used by the body to regulate sleep and wake cycles) wanes, and studies have shown that this can decrease hair growth."
R29 put this to Guy Parsons, expert trichologist and founder of My Hair Doctor. "As soon as one is experiencing poor sleep, it is fair to say the body is not functioning or preparing itself on a daily basis to a normal level, and as a non-essential tissue, hair is the last priority of the body." He added: "Sleep plays an important role in allowing the body to repair and regenerate, which includes the promotion of hair growth. Regeneration includes the body's turnover of cells and creating and regenerating new cells, all of which are essential to hair growth and can be greatly inhibited by sleep deprivation."
Parsons also mentions that insomnia can disrupt your physical and emotional health, and these changes can make the hair sensitive. "Hair loss can occur with such changes and in many cases, one of the chief causes of hair loss is lack of sleep. Your body gets weak without enough sleep and it fails to absorb nutrients to maintain health, resulting in a weakened immune system, loss of hair volume, hair condition, appearance and sheen." Diffused hair across the scalp and a receding hairline are also possibilities, according to Parsons, but it's important to note that hair growth can also be influenced by other factors, such as: "Trauma, stress and anxiety, family history, hormonal changes and use of certain medications."
As well as hair thinning or stunted growth, greasy roots are a symptom of a lack of sleep, Parsons says. "Increases in stress combined with lack of sleep causes a rise in the body’s production of the hormone cortisol. Raised cortisol levels are directly related to an increase in sebaceous oil production. Every hair on our head has its own small sebaceous gland under the scalp so any increase can affect the oil levels found on your head, making your hair greasier."
To counteract both issues, Parsons and Dr Khan suggest supplementing your diet with B vitamins to stimulate biotin production. Dr Khan also pinpoints vitamin C for fortifying hair structure. It also pays to practise self-care, whether that's breathwork, employing lavender, taking a proper bath or doing an at-home facial, to help reduce stress levels and induce sleep.
While you don't have to lay off the styling tools completely, it makes sense to protect your hair from damage, which could lop inches off your lengths. "You can use styling tools moderately with no adverse effects," explains Parsons. "However, I would suggest counterbalancing any heat styling with repairing treatments and masks."
R29 recommends KeraStraight's Protein Mask, £26, for repairing and smoothing. Sophia Hilton, hairstylist at Not Another Salon also suggests swapping your conditioner for a mask when you're washing your hair, as it hydrates and repairs on a much deeper level than conditioner. Invest in tools that aren't going to completely frazzle your hair. ghd's Platinum+ Styler, £175, ensures an optimum temperature of 185 degrees (much lower than most styling tools, but just as efficient) and senses the thickness of your hair to style in one pass, so you can expect fewer split ends and more shine.