Hair Can Actually Grow Faster In The Summer — Here's What To Know

If you've ever gotten a bad haircut or simply wanted longer locks and not have to wait for it, there's a pretty good chance you've Googled how to make your hair grow faster. And, during this process, you've probably found lots of claims — from diet to hair serums, to regular trims, to even satin or silk pillowcases — that suggest they hold the key to getting your hair to grow quicker than its usual half-inch a month.

But is there anything that can actually speed up the growth of human hair? "Good lifestyle choices and high quality, primary, unprocessed organic food can impact hair growth positively, [as can] drinking plenty of good quality spring water from different sources in the world," board-certified dermatologist Panos Vasiloudes, MD, Ph.D. told Byrdie. "These are simple ways to provide our body with micronutrients."

While this may certainly be true, because a healthy body is definitely going to lead to a healthier scalp and head of hair, these aren't the only things. In fact, the summer can actually make your hair grow faster too — and it's not a myth! Hold onto your pants, because the science behind this is going to blow your mind.

Our bodies need vitamin D and the summer is all about offering it up in the form of sunshine. According to a 2013 study published in Dermato Endocrinology, the earliest forms of life were completely reliant on sunshine for energy and the generation of carbohydrates in their teeny, tiny, microscopic bodies — we're talking about marine phytoplankton. Over time (and long before milk, cheese, and supplements were available), sunshine remained a mainstay in keeping people healthy and their organs functioning properly, with research finding that those who didn't have adequate access to sunlight suffered from physical and mental ailments.

Fast forward to today where we're already very well aware of the importance of vitamin D, but now we can narrow down the research and dive into specifics, like its impact on hair follicles. A 2007 study published in the Journal of Steroid Biochemistry and Molecular Biology found that vitamin D plays a major role in the correct functionality of hair follicles "which gives rise to the hair follicle keratinocytes and the underlying mesoderm which gives rise to the dermal papilla." Or, as we'd say in laypeople's terms, stimulates healthy hair growth.

If you live in a corner of the world that gets cold during some parts of the year, then you already know that trying to stay warm is a feat. That's because our blood struggles to circulate in a way that can keep us cozy from head to toe. However, the summer is prime time for proper blood circulation which leads to greater cell production, leading to more hair growth. Better Not Younger reported that your hair can actually grow about 10% faster simply because of better blood circulation.

On the flip side, a 2023 study published in Stat Pearls found that hair follicles that don't get enough blood circulated their way can result in hair loss. In other words, you want to make sure you have your head out there this summer, soaking up the sun.

Granted, hair growth is going to vary and other factors, like genes and lifestyle, are going to play a role too. But if you're hoping to get an extra half-inch or so this summer, then it doesn't hurt to give this method a try by loading up on the vitamin D and staying warm so your blood circulation can doing its thing.