While I would never want to diminish how essential a good SPF is (we do not stan wrinkles, sun burn, or skin cancer, TYVM), even the most health-minded of us all spend most of our time avoiding the sun and demonizing harmful rays. Yes, too much sun exposure can be damaging and even deadly, but sunlight contains powerful, life-giving energy too. In fact, sunlight impacts multiple hormonal functions, and hormonal function governs the health of every organ, system, and energy within the body–and while we don’t talk about it enough, this info is nothing new. In 1981, The New York Times published an article titled “From Fertility to Mood, Sunlight Found to Affect Human Biology,” and Hindus have worshipped the sun as a symbol of the Self-god (or our souls, divinity within us, etc.) for thousands of years.

How sunlight affects the body:

Improved energy and better sleep

How can one thing help you sleep better and get more energy–they’re opposites! Because of the circadian rhythm, the body runs on a 24-hour cycle (in addition to 25-30 day cycles in women)–this is how the body knows when to sleep and when to be awake. Thanks to lack of movement, artificial light at night, and many other factors of modern society, the body has trouble understanding where it is in the 24-hour cycle. Exposure to sunlight (especially in the morning) turns off melatonin production so the body knows it’s daytime and it is supposed to be awake (more energy), but it also kicks off the signal that the body should get sleepy in 12 hours because that’s how the circadian rhythm (or 24-hour cycle) works. Also, light frequencies from the light rays during a sunset (think oranges, reds, pinks, etc.) also send signals to the brain that it’s time to sleep.

Increased mood

It’s not a coincidence that you often feel happier after going for a walk or feel less stressed and moody on sunny days. Exposure to sunlight increases the brain’s release of serotonin, or one of the key happy hormones. Sunlight is also our main source of vitamin D, which regulates mood and depression (which is why seasonal affective disorder happens in cold months with less sun exposure).

Better reproductive health

Vitamin D not only improves mood, but is also associated with the health of estrogen and progesterone levels in women, and testosterone levels in men. Increased levels of these hormones are associated with increased fertility (in fact, a study in Finland found that conception rates peak in June and July when Finns are exposed to 20 hours of sunlight during the day), as well as more balanced periods, increased sex drive, etc. Also, your 24-hour cycle and menstrual cycle are deeply integrated (it’s how your body knows when it’s time to release an egg, etc.), so a healthy circadian rhythm due to proper sun exposure helps your reproductive cycle too.

Healthy weight management

According to a recent study, there’s a direct correlation to sunlight and having a healthy weight. The study found that adults who get sunlight in the morning are more likely to have a lower BMI. A big reason of this might be better sleep (because sleep is an important factor in weight management), but the the association between a lower BMI and morning light was still significant even after controlling the sleep time, which means the connection between fat loss and sun exposure was because of more than just sleep.

Tips for getting sunlight (without sun damage)

Spend as much time outdoors as possible, and open curtains and windows during the day to let in unfiltered daylight. But also be mindful of not letting yourself burn or over exposing your skin to the sun’s rays (even if you’re not prone to burning!). You only need about 15-30 minutes of sun exposure a day (varies based on skin tone: less time for lighter, and more time for darker) to get adequate vitamin D, melatonin regulation, etc., so aim for about 15 minutes of unprotected sun exposure a day (preferably in the morning when the sun rays are less harsh and you’re more likely to get the benefits of stopping melatonin production and increasing energy regulation). After that, go outside as often as you can throughout the day, but put on your SPF. If you can’t get 15-30 minutes of sun exposure because you’re prone to skin cancer cells, live in an area or season where sunlight is limited, etc. there are some artificial to mimic the benefits indoors. Try a sunrise-stimulating alarm clock in the morning, sunlight therapy lamp throughout the day, and switch to orange or red tinted lightbulbs at night.