Vitamins, minerals, and sleep are all required for health, but there is another nutrient you may be missing: light. The light you see as you’re waking up in the morning is more than just light to your eyes; it’s a raw material that can stimulate the entire endocrine system.
Your eyes have special light receptors that detect the brightness of the morning sky and directly transmit a signal to your brain’s master clock. This signal lets your brain know it’s daytime and releases your daytime hormones, such as cortisol and dopamine.
If you don’t get these morning sunlight benefits, your brain doesn’t get the signal to begin its hormonal cycle, and you end up being drowsy all day.
There is also a direct connection between less morning light exposure and hormonal imbalance, inadequate sleep, low mood, weight gain, weakened immunity, and poor cognitive function.
Morning Sunlight and the Circadian Rhythm
Your circadian rhythm is your body’s 24-hour internal clock. It regulates the release of hormones, food digestion, and the repair of your cells. Even before we had alarm clocks or smartphones, the sun was our only timekeeper!
The human body has a built-in biological clock that wakes us up when it’s morning and goes to sleep when it’s night. This internal clock is very much hormone-dependent and relies on a certain external signal to tell what time it is.
The three times your body is most alert to light are the first hour after waking, the two hours before bed, and during the middle of the night. The color and intensity of the sun naturally change throughout the day. You must try to simulate this natural light cycle as early as possible to maintain the perfect hormone balance.
When you get this right, the impact on your body is massive. Your sex hormones, such as estrogen, progesterone, and testosterone, operate within the same 24-hour rhythm. If your clock is confused because it never sees the sun, your body thinks you are in a state of environmental stress and stops prioritizing reproduction.
How Much Time Do You Actually Need?
No sun-baking is necessary to achieve the morning sunlight benefits. The right amount of time is different for everyone. It is based on your skin tone, age, and location.
For lighter skin tones, 5-15 minutes of direct sunlight is sufficient for the hormonal change to occur. Those with darker-colored skin may require 30 minutes, as melanin gives some protection from the light. You can stay outside longer if you apply sunscreen after that initial window, but those first few minutes of bare-eye, unfiltered light are what lock in your clock.
Key Morning Sunlight Benefits
1. Morning Sunlight Wakes You Up
When the light comes into your eyes in the morning, it sends a signal to your brain to completely turn off melatonin (your sleep hormone) and activate the healthy production of cortisol.
Cortisol may be referred to as a stress hormone, but it is actually essential to wake up in the morning, and the body naturally produces more of it during that time. This particular cortisol release is what gets the groggy weight off your brain and provides you with steady, crisp energy all day.
Researchers have revealed that individuals who were exposed to bright natural light in the early morning experienced a much more robust and adequate cortisol awakening response than those who remained indoors in artificial light.
2. It Promotes Sleep
It may seem backward, but you do need light in the morning to sleep at night. You’re setting your internal clock in the morning with all this natural light. This ensures that 14-16 hours later, your brain is fully aware that it’s time to go to sleep and start releasing melatonin.
Studies revealed that bright morning light advances the internal clock earlier. As a result, your brain will automatically produce sleep hormones earlier and more intensely that night, and you will be able to fall asleep without tossing and turning.
3. It Enhances Your Mood
When sunlight hits your eyes, it triggers an immediate release of serotonin and dopamine. These are the chemicals that help you to feel relaxed, happy, and motivated.
Without this morning light, your brain has trouble making enough of these chemicals during the day, making you susceptible to brain fog, lack of motivation, and low mood.
Additionally, the serotonin you make in the morning is actually stored and used as the raw material to make your melatonin(sleep hormone) at night.
One famous study showed that the production of serotonin in the brain is linked to the duration of exposure to bright sunlight. In the dark days or during winters, serotonin production is significantly reduced.
4. It Balances Your Hormones
All hormones in the body, including estrogen, progesterone, testosterone, and insulin, follow a 24-hour cycle. The morning sun tells your body that it’s safe and normal. If your internal clock never sees the sun, your brain thinks you are in a state of environmental stress.
In such a case, your body will no longer be able to focus on non-essential activities such as reproduction and digestion at its best. Circadian rhythm disruption is directly known to decrease sex hormone levels, as reviewed. This is exactly how the morning sunlight helps your hormones naturally; it sets in your internal clock and ensures your body is producing and balancing your sex hormones and metabolism properly.
5. It helps with Metabolism
Your internal clock instructs your stomach on when to eat and when to digest. Morning light increases insulin sensitivity, allowing your cells to deal with the food much better all day.
If you do not have it, your blood sugar and weight can be difficult to regulate.
Why Does Looking Through a Window Not Work?
Many believe that sitting in a car or a room with sunlight is enough. It does not.
Modern glass blocks out a massive portion of the light spectrum your brain needs to trigger that hormone cascade. The morning light must be directly hitting your bare eyes. This is not about looking directly into the sun, but simply the presence of the sky in the field of view is enough. Also, sunglasses will interfere with the signal, so remove them for the first few minutes outside.
The Morning Sunlight Protocol
The research findings on the merits of early morning sunlight aren’t just interesting and persuasive, they’re practical. Here is what to do to make this a healthy lifestyle:
Get outside early:
Try to get outside within 30 to 60 minutes of waking up. The first 30-60 minutes after waking up is the most sensitive time for hormonal effects. Even on overcast days, outdoor light is typically 10,000–25,000 lux, far brighter than the 100–500 lux of a well-lit indoor room.
So, outdoor light, even on a cloudy day, is many times stronger as a circadian cue than the light you have at home, no matter how bright you think it is.
Avoid wearing sunglasses during this time
Take off your sunglasses for the first part of your walk. If you already wear prescription glasses, remove them temporarily, if possible, because some glasses block the spectrum of light that your brain requires.
Do not look directly at the sun; you do not need to. You need to look in the general direction of the sky and let the natural light in; no filters are needed.
On a sunny morning, 5–10 minutes of sunlight exposure is sufficient. On a cloudy day, aim for 15–20 minutes to compensate for lower light intensity.
Do Light Exercise in the Morning
When you do exercise outside in the morning, whether it’s a walk, a quick run, or a simple stretch, this gives you enormous health benefits compared to these interventions alone.
Try to go outside for 5-10 minutes on a sunny morning. If time allows, you can do more, and if you have an opportunity to use time outside, exercise, walk, eat a light breakfast, or journal in the sun.
Protect Your Evenings From Artificial Blue Light
Once it gets dark, artificial light, especially the blue LED light emitted from phones, tablets, overhead lights, and computer screens, tricks your SCN into thinking it’s still daytime and helps to suppress melatonin levels, delaying your sleep.
The following practical evening light hygiene is recommended:
- Use dim, warmer, and lower-intensity lighting after 8–9 p.m
- Switch to night mode on mobile
- Try using blue-light blocking amber glasses for screen time at night
- Don’t use bright overhead lighting in the 1-2 hours before bed
- Keep your bedroom as dark as possible during sleep
What If You Can’t Get Outside in the Morning?
Sometimes, outdoor exposure in the morning isn’t possible. Here is what to do in this case:
- Get a light therapy box. A 10,000 lux SAD lamp for 20-30 minutes is a proven alternative to outdoor morning sunlight for circadian phase entrainment, melatonin timing, and mood regulation. While eating breakfast or reading, place it at eye level, about an arm’s length from the eyes. Avoid looking directly at it.
- Maximize indoor light immediately on waking. Open all blinds and curtains when you get up. If you can, sit close to a window facing south.
- Go outside early in the day. If it is not possible to get outside within the first 30 minutes, any outdoor light that is received 1-2 hours after waking offers a significant circadian advantage.
- Take advantage of commuting. Use walking or cycling to get to work. Take a break from work outside and eat lunch outdoors.
Conclusion
In functional medicine, the use of sunlight is actually one of the most basic treatments used for everything from hormonal imbalances to thyroid issues, metabolic disease, mood disorders, chronic fatigue, and sleep disorders.
To get the full morning sunlight benefits, 5 to 10 minutes may be enough to lock in your clock on sunny days, while cloudy days may require closer to 20 minutes.
Morning sunlight benefits go far beyond just your hormones; scientists also think that specific rays from the sun may interact and shrink fat cells below your skin’s surface. One of the simplest ways to stay healthy is to build a morning sunlight routine.
At Kairos Health and Wellness, Lola, one of our functional health providers, will take the time to look at your unique biology and build a personalized, easy-to-follow plan to get your energy, sleep, and hormones back on track.
If you have any questions or concerns, call us today!