Originally published on VivaRays, this article is shared with express permission and our own introduction and conclusion. ย We believe this is important information for our subscribers and are grateful for the collaboration.
TL;DR: Most chemical sunscreens flood your bloodstream with endocrine disruptorsโoxybenzone alone peaks at 500 times the FDA’s safety threshold within hours of a single application. The only genuinely safe option for a nontoxic sunscreen is a non-nano zinc oxide mineral formula. Your skin builds its own protection through gradual sun exposure, and melatoninโyour body’s most powerful antioxidantโrepairs sun damage while you sleep.
A Note from SAMINA Sleep
At SAMINA Sleep, we spend a lot of time talking about what happens after dark. The mattress you sleep on. The absence of metal in your bed to mitigate EMF effects. The natural materials that make for the best bedding. The darkness that lets your nervous system finally relax. Your body needs specific conditions to do its deepest repair workโand we’ve built an entire sleep system around them.
But hereโs something weโve learned through years of research and through the work of people we deeply respect: a great sleep begins long before you close your eyes. How well you sleep at night begins at sunrise every morning.
โ๏ธ Summer sunlight is the most powerful circadian reset available to you. The light that enters your eyes within the first hour after you wake up triggers cortisol and this is precisely the moment your biological clock gets set. This tells your body when to release melatonin hours later. Your circadian rhythm runs on light. And light runs on timing. No supplement fully replicates that biological signal either.
That connectionโbetween morning sun, melatonin production, and the quality of your overnight repairโis exactly what drew us to the work of Ashur Mattar, a circadian rhythm expert who is the co-founder and CEO of VivaRays. Their companyโs approach to light, from the circadian glasses they design to the sun health education they publish, aligns with SAMINA and what we believe about sleep. Namely, the light that enters your eyes affects your body shaping what your cells do at night.
The guide below is one of the clearest, most research-grounded pieces we’ve read about sunscreen, your health, and touches upon sleep, too. It covers what most people get wrong or just plain donโt know about conventional sunscreen. Specifically, it reviews the chemicals in sunscreen products that enter your bloodstream and how your skin was designed to protect itself before the industry sold you a bottle of chemicals. It also clearly guides you to choose a truly clean mineral sunscreen for the times you really should use one. We believe this belongs in every health-conscious household. Read it carefullyโand pay particular attention to the section on melatonin. That’s where sunshine meets your sleep.
Why most sunscreens make you less safe, not more
I want you to imagine an experiment.
You take a fresh bottle of conventional SPF 30. You apply it the way the label tells you to, all over the body, the way millions of people do every summer day.
Now somebody draws your blood a few hours later.
What do you think they find?
In 2020, the FDA actually ran this experiment. The results were published in JAMA, one of the most respected medical journals on the planet.
Six UV filters were tested and every single one flooded the bloodstream with endocrine disruptors within hours.
Oxybenzone peaked at 258 nanograms per milliliter in human blood. The FDA’s own safety threshold for a chemical filter is 0.5 nanograms per milliliter.
That’s 500 times higher than the threshold their own scientists set.
And here’s the part that should make you rethink everything you’ve been taught about sunscreen.
Some of those chemicals were still detectable in the blood seven days after the last application.
๐ก Research: Matta et al. (2020) ran a randomized maximal-usage trial on six chemical filters: avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate. All six exceeded the FDA’s 0.5 ng/mL plasma threshold after a single day of normal application. Oxybenzone reached 258.1 ng/mL with lotion and 180.1 ng/mL with aerosol spray. Several remained measurable in plasma 21 days later. The authors concluded that all six warrant further toxicological study before being classified as Generally Recognized As Safe and Effective. Read the full JAMA study here.
Now ask yourself this.
If a food product was found at 500 times the safety threshold of its own regulator, would you eat it?
If a baby product was that far out of range, would you use it on your child?
Yet we rub this on the largest organ in our body. We rub it on our kids. We do it every two hours and call it protection.
That’s the first thing you need to see clearly.
What your skin was built to do (before we sold it a bottle)
Melanin isn’t a pigment. It’s a battery.
I grew up in Lebanon.
My grandparents lived under that Mediterranean sun their whole lives. They farmed. They walked to the market at noon. They sat in the shade after lunch and went back out in the late afternoon.
None of them owned a single bottle of sunscreen.
None of them had skin cancer.
The first time I really thought about why, I was in my late twenties, knee-deep in chronic fatigue and burnout, reading everything I could about how light works on the body.
That’s when I learned about the solar callus.
Your skin is designed to absorb sunlight.
When UVB hits your skin gradually, the melanocytes in your epidermis start producing melanin.
Melanin (the brown pigment that creates a tan) is what makes you tan beautifully.
It’s also the original sunscreen, written into your body before anyone invented a bottle.
Most people stop the story there.
But melanin is doing far more inside your body than coloring your skin.
- Melanin neutralizes free radicals.
- It quenches reactive oxygen species.
- It tells your immune system when to stand down.
- And it protects every cell underneath your skin from oxidative damage (Hong et al., Int. J. Mol. Sci., 2026).
That alone would make it one of the most valuable substances your body produces.
But here’s where it gets fascinating.
Peer-reviewed research has shown that melanin actually conducts electricity.
It functions as a semiconductor inside human tissue, and it absorbs light across nearly the entire UV and visible spectrum (Mostert et al., PNAS, 2012; Cao et al., Chem. Rev., 2024).
This literally means the Melanin absorbs sunlight and converts it into electrons that your cell can use to do real work.
Think of it like tiny solar panels layered into your skin.
Sunlight hits, charge is generated and your body gets a clean, ambient energy source that fuels you.
The more melanin you build through slow, gradual sun exposure, the deeper your reserve becomes. The greater your reserve is, the more resilient you are to every kind of stress your body deals with daily.
Why is that?
It turns out that when your body is under stress, your body starts using its Melanin reserve to deal with the stress.
Think about the hours of blue light exposure from screens, sitting under LED lights all day, taking a long flight, and being exposed to Wi-Fi at night. All of these are highly inflammatory, and they require your body to use Melanin to deal with all the inflammation. Your body responds by mobilizing melanin to neutralize the damage.
You can actually test this in real time:
- Before a long flight, build up a beautiful tan and take a picture of yourself before you fly.
- Take another picture after you have landed.
- Compare your Melanin levels: Before and after flying.
You will see that after a few hours of flying on the plane, you had lost a lot of your tan. That’s literally your body mobilizing Melanin to neutralize the damage and inflammation from flying.
๐ก Research: Hong, Lim & Kim (Int. J. Mol. Sci., 2026) document melanin as a free radical scavenger, reactive oxygen species quencher, immune modulator, and broad-spectrum photoprotectant (PMC link). Mostert et al. (PNAS, 2012) demonstrated that melanin functions as a hybrid electronic-ionic semiconductor in biological tissue, capable of conducting both electrons and protons (PNAS link). Cao et al. (Chem. Rev., 2024) reviewed melanin’s redox-active properties, electron transport capacity, and photoprotective mechanisms across biological and synthetic systems (ACS link). The “human photosynthesis” hypothesis (melanin actively splitting water under light) was first proposed by Dr. Arturo Solis Herrera in a 2007 Nature Precedings preprint. That specific water-splitting claim remains debated outside his lab, but the underlying property (light-driven electron generation in melanin) is now established in mainstream peer-reviewed work.
And melanin is only one of the gifts.
The same sunlight that builds the callus also triggers vitamin D synthesis, alpha-MSH (the hormone that regulates appetite), and beta-endorphins (the molecules that make you feel calm and happy in the sun).
It’s a whole hormonal cascade and it only fires when light actually touches your skin.
๐ก Research: A NHANES analysis of 71,685 US adults from 2001 to 2018 found that 24.6% were vitamin D deficient and 40.9% were insufficient. Using the optimal range of 40 to 60 ng/mL, roughly 90% of US adults fall below. Vitamin D is synthesized in the skin from UVB exposure and supports immune function, mood, bone health, and metabolic resilience. SPF 8 sunscreen blocks roughly 92% of vitamin D synthesis. SPF 30 blocks ~95%. (Cui et al., 2022)
How your body actually builds a solar callus
Now the obvious question.
If melanin is this powerful, how do you actually build it?
Think of it like calluses on a farmer’s hands. You don’t build them in a day. You build them through repeated, gradual contact with the work. And once they’re there, they protect you the rest of the season.
Your skin works the same way. Spring is the training season. Summer is the payoff. (PS: it is still never late)
Here’s the simplest protocol: (Read this article to dive deeper)
1 โ Weeks 1 to 3. Start with 15โ60 minutes of bare-skin sunlight in the early morning. No sunscreen. No sunglasses. Just light on your face, arms, and chest as you sip your coffee. Combine this with 2 to 5 minutes of midday sun: anytime between 11:00 am and 2:00 pm.
2 โ Weeks 4 to 6. Continue your morning exposure and add a few minutes of midday sun. Build from 5 all the way up to 20 minutes of exposed skin. Step into shade before pink shows up.
3 โ Week 7 and beyond. Your melanin is online. You can start slowly increasing your exposure beyond 20 minutes, and using your intuition and wisdom to stop when your skin is giving you a signal that it’s enough. At that point a hat and clothing become your primary protection. Mineral sunscreen is reserved for long peak-hour exposure.
That’s the entire build.
If you skip the training season and head straight into summer weekend at noon, your skin is unprepared, your melanin reserve is empty, and the burn is inevitable.
The chemicals in the bottle cannot replace the work that you need to do in order to prepare your skin for sunlight.
How many sunscreen ads mention any of this?
None of them do.
Because here’s the uncomfortable truth.
If your body can build its own protection, the bottle becomes unnecessary.
The Sunscreen paradox: why melanoma keeps rising
There’s a strange chart almost nobody shows you.
Plot the rise of sunscreen use against the rise of melanoma over the last forty years. The two lines climb together.
Sunscreen sales tripled. Melanoma rates tripled too.
If sunscreen worked the way the bottle promises, you’d expect the opposite. You’d expect melanoma to fall as the cream spread.
Instead, the more we slather, the more we burn.
Dr. Ivan Litvinov, a dermatologist at McGill University, has a name for this. He calls it the “sunscreen paradox.”
His research suggests sunscreen creates a false sense of security. People apply it, then stay out longer than they otherwise would. They overexpose themselves. They skip the hat and skip the shade.
And many of the chemical filters break down in sunlight.
When they break down, they generate free radicals on your skin, the very thing the cream was supposed to prevent.
It’s like pouring gasoline on the fire you’re trying to put out.
๐ก Research: Avobenzone, the most common UVA filter in chemical sunscreens, is photo-unstable. It degrades within hours of sun exposure into compounds that generate reactive oxygen species (free radicals) on the skin’s surface. Octocrylene, frequently added to “stabilize” avobenzone, degrades on the shelf into benzophenone, a probable human carcinogen per the IARC. Melanoma incidence in Canada rose by roughly 17% between 2020 and 2024, despite record sunscreen sales. (Litvinov, McGill University, 2024)
Let that sink in.
The ingredients to stop using today
The first step is to flip the bottle.
The front of the bottle is marketing. The back of the bottle is the truth.
If you see any of the names below in the active ingredient list, put it down and walk away.
Oxybenzone (Benzophenone-3, BP-3) โ ๏ธโ ๏ธโ ๏ธ
The worst offender on the list.
It’s an endocrine disruptor. Studies have linked it to lower testosterone in adolescent boys, abnormal mammary gland development in mice at human-relevant doses, and the ability to bind to estrogen receptors and proliferate breast cancer cells in lab settings.
The CDC has measured oxybenzone in the urine of 97% of Americans.
And it bleaches coral reefs. Hawaii banned it in 2021. Key West banned it. Aruba and Palau banned it.
What you’re putting on your skin is now in your bloodstream, your urine, and the ocean.
๐ก Research: A NHANES cross-sectional analysis of US adolescents found a significant inverse association between urinary BP-3 levels and total testosterone in adolescent boys (Scinicariello and Buser, Environmental Health Perspectives, 2016). LaPlante et al. (2018) found that oxybenzone exposure at doses comparable to human use altered mammary gland development in mice and proliferated MCF-7 human breast cancer cells in vitro (J Endocr Soc, 2018). CDC biomonitoring data: 97% of Americans tested positive for BP-3 in urine.
Octinoxate (Octyl methoxycinnamate) โ ๏ธโ ๏ธ
Estrogenic. Disrupts thyroid hormone signaling. Highly toxic to coral.
Often paired with oxybenzone in conventional drugstore sunscreens. The two of them together are the reason Hawaii passed the first statewide reef ban in 2018.
Octocrylene โ ๏ธโ ๏ธโ ๏ธ
This one is sneaky.
Octocrylene degrades into benzophenone, a compound the International Agency for Research on Cancer classifies as Group 2Bโa possible human carcinogen. The degradation happens in the bottle, on the shelf. So even if you bought it fresh, by the end of the summer it’s worse than when it started.
Homosalate โ ๏ธโ ๏ธโ ๏ธ
Another endocrine disruptor. Disrupts estrogen, androgen, and progesterone signaling.
The European Union restricts its use in cosmetic products. The FDA still allows up to 15% concentration in the United States.
Avobenzone โ ๏ธโ ๏ธ
Photo-unstable. Breaks down under UV exposure into free radicals on your skin.
Imagine putting on a coat to keep warm, and the coat slowly turns into ice as you wear it. That’s avobenzone.
Octisalate โ ๏ธโ ๏ธ
On its own, less concerning than the others. But it’s a penetration enhancer. It helps the other chemicals get deeper into your skin and into your bloodstream.
If oxybenzone is the bullet, octisalate is the gun.
Retinyl palmitate (Vitamin A palmitate) โ ๏ธโ ๏ธ
This one shows up in moisturizers and sunscreens labeled as “anti-aging.”
Here’s the cruel joke. Retinyl palmitate is a form of vitamin A that, when exposed to UV light, has been shown in National Toxicology Program studies to accelerate tumor formation on the skin of test animals.
A skin cancer accelerator. In a sunscreen. Marketed for daily use in the sun.
Parabens, fragrance, methylisothiazolinone, nanoparticles
Parabens (methyl, ethyl, propyl, butyl) are xenoestrogens. They accumulate in breast tissue.
“Fragrance” or “parfum” is a legal black box. It can hide dozens of undisclosed chemicals, including phthalates and synthetic musks.
Methylisothiazolinone (a preservative) was named Allergen of the Year by the American Contact Dermatitis Society. It’s a common cause of contact dermatitis in kids.
Nanoparticles in sprays are a separate problem. The mineral itself (zinc oxide) is safe on intact skin, but the European Chemicals Agency restricts nano zinc oxide in spray form because the particles can reach the lungs, where the body has no good way to clear them.
If you went to the drugstore right now and grabbed a random sunscreen off the shelf, four out of five would fail a clean safety review.
That’s the industry you’ve been trusting to protect your kids.
ย ย ย โ ๏ธโ ๏ธ Indicates the FDA “GRASE” (Generally Recognized as Safe and Effective) status is deferred or remains under continuous review.
โ ๏ธโ ๏ธโ ๏ธ Indicates the FDA officially revoked the “GRASE” (Generally Recognized as Safe and Effective) status of this chemical compound as of July 2026.
How to read a mineral sunscreen label: the 4 criteria that matter
Now the good news.
You don’t need a degree in cosmetic chemistry. You don’t need to memorize a list of fifty bad ingredients. You just need four rules. Apply them at any store, anywhere in the world, and you’ll be right almost every time.
- Non-nano zinc oxide is the only active ingredient. Not “and titanium dioxide.” Not “and avobenzone.” Just zinc. Aim for a concentration around 20 to 25 percent. Zinc oxide is the only ingredient that provides true broad-spectrum protection (UVA and UVB) by sitting on top of the skin and physically reflecting the light.
- ย Zero chemical filters. Scan the active ingredient list for any name ending in “-benzone,” “-salate,” “octo-,” or anything called “avobenzone.” If you see any of them, even in a tiny amount, put it down. Zinc does the whole job by itself.
- Short ingredient list. Recognizable words. A clean mineral sunscreen has maybe 6 to 10 total ingredients. Things like zinc, shea butter, cocoa butter, beeswax, jojoba oil, tallow, vitamin E (from non-soy sources). If you can’t pronounce half the list, something is hiding.
- No fragrance, no parabens, no PEGs, no phenoxyethanol. “Fragrance” or “parfum” is a legal hiding place for dozens of undisclosed chemicals. Parabens, phenoxyethanol, and PEGs are preservatives and surfactants with their own endocrine concerns. A truly clean mineral sunscreen doesn’t need any of them.
That’s the whole framework.
Flip the bottle. Read the active ingredient line. If it’s anything other than non-nano zinc oxide, put it back. Then read the inactive list. If it has fragrance or parabens, put it back.
What you’re left with on the shelf will be small. Maybe one or two options. That’s normal.
Clean is a small category. Loud is a big one.
๐ก Research: Multiple reviews (over 50 studies) confirm that zinc oxide does not penetrate intact, healthy skin at either nano or non-nano size. It sits on the stratum corneum and is washed off in the shower. Non-nano (greater than 100 nm particle size) is preferred where possible because compromised or broken skin may allow some absorption of smaller particles. The European Chemicals Agency restricts nano zinc oxide in spray form due to inhalation risk, since particles small enough to reach the deep lung cannot be cleared by the body’s normal mechanisms. (EWG, 2025)
When do you actually need sunscreenโand when don’t you?
Here’s where I want to be careful.
We’re not anti-sunscreen. We’re anti-sunscreen dependence. There’s a difference.
Think of sunscreen like a tool, not a uniform. You wear it when you actually need it. You don’t wear it as a constant baseline.
Here’s when the bottle stays in the bag.
1.ย ย ย ย Morning sun (sunrise to about 10 a.m.)
This is the most important light of your day. It sets your circadian clock, kicks off cortisol production, and triggers the hormones that build sun tolerance later.
The UV index at sunrise is essentially low. You cannot burn at 7 a.m.
Go outside. Face the sun and stay for as long as you can. No sunscreen, no sunglasses.
2.ย ย ย ย Mid-morning, once your solar callus is built
This is the season you’re in right now.
If you’ve been outside daily since early spring, exposing your skin gradually, you’ve built a baseline. Your melanin is up. Your skin can handle real UVB without burning.
Most of the day, you don’t need a bottle. You may need the wisdom to step into the shade when needed.
3.ย ย ย ย Peak hours, with no solar callus, no shade, and no clothing option
This is when sunscreen earns its place.
You’re at the beach. You’re on a hike. You’re at the waterpark with your kids. There’s no escape, no shade and you’ll be there for hours.
This is the moment for clean, non-nano zinc on the exposed skin. Face, shoulders, tops of feet. The places that catch the sun first.
What to pair with mineral sunscreen for real sun resilience
Your skin is one part of a bigger system.
The sun resilience you’re after is built on a few things to layer in.
Real food fats. Grass-fed butter, pasture-raised eggs, wild-caught fish, olive oil, raw nuts. The cell membranes of your skin are made of fat. Healthy fats build healthy membranes. Sun-resilient skin starts at the cellular level, and the cellular level is built in the kitchen.
Astaxanthin. A red pigment from microalgae, the same molecule that makes wild salmon pink. It’s been called an internal sunscreen because it accumulates in your skin and helps quench the free radicals produced by UV exposure.
Protect your melatonin like it’s a vault. Most people think of melatonin as a sleep hormone. It’s far more than that.
Melatonin is the highest antioxidant nature has ever made.
- It scavenges free radicals inside your cells.
- It repairs sun-damaged skin overnight.
- It is the most powerful internal sunscreen your body has, and it costs nothing to make.
You just have to let it rise naturally at night.
But the moment artificial light hits your eyes after sunset, melatonin production stops.
The kitchen LEDs. The Netflix TV. The phone in bed. Every blue and green wavelength after dark suppresses melatonin and shuts down the repair shift your skin was waiting for.
That’s why we built VivaRays 3-in-1 Circadian Glasses.
Three lenses in one frame.
Daytime for the daytime hours when you’re exposed to the inflammatory frequency from your screens and office lights. Evening orange for sunset through dinner. Red nighttime for the last hour before bed. Together, they protect your morning circadian signal AND your evening melatonin in a single device that lives on your face from sunrise to bedtime.
Sleep in real darkness. Once the lenses come off at bedtime, the room itself has to be dark too. Even small amounts of light in the bedroom suppress melatonin. Black out the windows. Cover the LEDs on your devices. Your skin will heal faster, and your tan will deepen instead of peel.
Frequently asked questions about sunscreen
Is mineral sunscreen actually safer than chemical sunscreen?
Yes. The FDA recognizes only zinc oxide and titanium dioxide as Generally Recognized As Safe and Effective. All other chemical filtersโoxybenzone, octinoxate, octocrylene, homosalate, avobenzone, octisalateโremain in Category III, meaning the FDA does not yet have sufficient data to confirm they’re safe. The 2020 JAMA study showed all six absorb into human blood at levels above the safety threshold within hours. Zinc oxide does not absorb through intact skin.
What does “non-nano” zinc oxide mean, and why does it matter?
Non-nano means the zinc oxide particles are larger than 100 nanometersโthe threshold the European Union uses to classify a particle as a nanoparticle. Larger particles stay on the surface of the skin and cannot be inhaled deeply if accidentally aerosolized. Nano-sized zinc is generally safe on intact skin, but the European Chemicals Agency restricts it in spray sunscreens because tiny particles can reach the lungs.
Can I still get vitamin D while wearing a mineral sunscreen?
Most people get enough vitamin D from the times they’re not wearing sunscreenโearly morning sun on bare skin and short outdoor breaks during the day. A 2019 review found SPF 30 sunscreen reduces vitamin D synthesis by roughly 95% when applied perfectly. In real life, most people miss spots and reapply unevenly, so some synthesis still happens. The cleanest fix: get morning sun without sunscreen, then apply mineral only during peak-hour beach days.
Is titanium dioxide as safe as zinc oxide?
Both are recognized as safe by the FDA, but zinc oxide is the better choice. Zinc offers true broad-spectrum protection across UVA and UVB. Titanium dioxide protects strongly against UVB and short UVA but is weaker against long UVAโthe wavelength most linked to deep skin aging and DNA damage. A clean mineral sunscreen with zinc as the only active is the simplest, most reliable choice.
How much zinc oxide concentration is enough?
For real protection during peak sun exposure, look for a concentration in the 20 to 25 percent range. This typically corresponds to roughly SPF 30 to SPF 50 in mineral formulations. Lower concentrations (10 to 15 percent) can work for daily incidental sun, but for a beach day, a boat day, or a hike at altitude, go higher. The active percentage is always listed at the top of the back label.
The Sleep Side of Sun Protection โ A Final Word from SAMINA
Everything described in this article connects back to biological truths that SAMINA has been saying for decades: your body does its deepest repair work at night, and only when the conditions are right.
Melatonin is the bridge. During the day, your melanin shields you from oxidative damage. At night, your melatonin repairs it and the two are not separate systemsโthey are two phases of the same cycle. Disrupt one, and the other can’t do its job.
This is why we say: sun protection begins at sunrise and only ends after dark.
Your morning sunlight builds the melanin that shields you through the day. Your evening darkness restores the melatonin that heals you through the night.
A phone screen at midnight can delay your melatonin peak by two to three hours and during those lost hours, your skin does not repair.
The UV damage from the day lingers. The free radicals accumulate.
The cycle never closes.
At SAMINA, we have spent almost 40 years designing sleep environments that give melatonin the natural conditions it needs to do its full work: metal-free, natural, and non-toxic sleep systems. This starts with nontoxic materials like bio-active virgin wool, natural rubber latex, and organic materials to help regulate temperature and moisture while supporting your spine all night long. The SAMINA healthy sleep system, while supremely comfortable, is about giving your body what it needs so you can get interrupted, restorative, and regenerative sleep every night.
If this guide has shifted how you think about your skin, your sunscreen, and your sleep, two steps are worth taking today.
Step 1: Explore VivaRays’ circadian glasses. We love them! The modern world is illuminated with artificial light. For your best sleep, your eyes require special protection. These glasses have three different lenses to use for different phases of the day and unnatural light. Especially for sensitive sleepers, discover the difference full day circadian rhythm protection provides you and protects your sleep. As a SAMINA Sleep reader, enjoy a discount from us for your entire VivaRays order. Simply use the link below:
๐ Shop VivaRays with your exclusive SAMINA discount โ vivarays.com/samina-sleep
Step 2: Your body was built for sunlight. It was also built for darkness. Give it the best of both. Take a look at what you’re sleeping on. The sleep environment is where your skinโand your whole bodyโdoes its overnight repair. If that environment isn’t working for you, we’d like to help.
๐ saminasleep.com | โ๏ธ info@saminasleep.com | ๐ 1-877-494-1091 (Toll-free, US & Canada)
Reprinted from the original published article with permission.
