We may earn commission from links on this page, but we only recommend products we love. Promise. As someone who constantly wears slicked-back updos, is a hair-bleaching retiree, and is still recovering from an overly short haircut last year, I'm very focused on improving my overall hair health. I use everything from hair growth serums to strengthening shampoos and conditioners, and I’m also a major proponent and consistent user of hair-growth devices. There's tons of these tools on the market that promote hair growth and scalp circulation via LED, and I'm most loyal to . Out of all the helmets and brushes out there, it's the easiest to use, and the most subtle. While many red light therapy helmets and headbands can really only be worn in the comfort of your bedroom, and brushes require you to stroke them through your strands for at least five minutes to get the full effect, this accessory lets your red-light treatment fly under the radar—so much so that you can even wear it in public. About the HigherDOSE Red Light Therapy Hat Light sources: 120 120 Usage: 10 minutes daily 10 minutes daily Price: $449 From the outside, it looks like your regular branded baseball cap. But on the inside, there are actually 120 LED lights emitting red light (with a wavelength of 650 nm, aka the same strength as your beloved red light mask) directly to your scalp. Red light therapy helps create a healthier scalp environment so hair follicles can function at their best. The wavelengths penetrate the scalp to boost circulation and help deliver oxygen and nutrients to the follicles, which is why these devices can work even better when paired with a hair serum that's packed with nourishing ingredients. FWIW, there isn't enough data to really prove that red light therapy really works for hair growth just yet (more studies have to be done for a definitive answer). But the anecdotal evidence is definitely there, and I've noticed it firsthand. Jasmine Hyman for Cosmopolitan And luckily, when you wear the cap and turn it on (there's a mini battery on the back that you just click to start), you can't see any red light coming from the hat. It just looks like a plain ol' cap, and despite the padding and lights, it's actually comfortable to wear. I even keep a spare one sitting at my desk, and no one in the office knows when I'm undergoing a full hair-strengthening treatment. Plus, the battery life itself is another win—you only need to charge it fully once every few weeks. If you want to improve your scalp health with a low-fuss, discreet device, the HigherDOSE hat is our top pick (and we've tested dozens). Yes, $449 is an investment, but its ease of use makes it worth it for any hair journey. Unlike bulky helmets or complicated gadgets, you can realistically wear it every day, and when it comes to hair growth, consistency is everything. This discreet cap makes it simple to get your red light therapy in without disrupting your day. Why Trust Cosmopolitan? Jasmine Hyman is the assistant beauty editor at Cosmopolitan who covers all things hair. She's owned the HigherDOSE red light hat for over a year and consistently writes and tests the effects of LED therapy.