Perfecting your morning routine can be a serious game changer, and while we’ve seen our fair share of fads (bulletproof coffee, anyone?), there’s one trend that continues to feature in the a.m. rituals of the super healthy. Gwyneth Paltrow swears by it, and Miranda Kerr says it helps with digestion. The best part? It costs less than $1 to make. According to Health, the best way to start your day is with a glass of lemon-infused water.

Why? “Lemon is packed with vitamin C, which can help boost the immune system,” says Amy Myers, doctor and author of The Autoimmune Solution. As an added bonus, it’s also “very high in bioflavonoids that destroy harmful free radicals that damage blood vessels and cause inflammation,” osteopath Vicky Vlachonis tells Health.

If you’re ready to try this health hack, experts recommend against chilled water. Our body absorbs room-temperature water more efficiently in the morning, so squeeze up to half a lemon in a glass to reap the benefits.