14/05/2026
We’ve all been there. We’ve had one of those days where the inbox is overflowing, our muscles feel like they’re made of rusted iron, and the only thing we want to do is crawl into a warm tub and disappear. Usually, that involves grabbing a big, dusty bag of epsom salt from the back of the cabinet and dumping it in. We’ve been told for years that these salts are the secret to magnesium replenishment, but we rarely stop to ask if they’re actually doing the heavy lifting we expect. At Flewd Stresscare, we started our journey in 2020 because we realized that the way we handle stress—and the way we supplement for it—needed a serious upgrade.
In this article, we’re gonna dive deep into the science of transdermal absorption to see if those salts are really sinking in or if we’re just making expensive human soup. We’ll explore the difference between various forms of magnesium, why our skin acts like a stubborn bouncer at a club, and how we can actually get the nutrients we need to feel like ourselves again. The truth is, while the classic soak has its merits, the science of how we absorb minerals through our skin is a lot more nuanced than just "add salt and stir."
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To understand if we’re actually absorbing anything, we first have to look at what we’re putting in the water. Epsom salt isn't actually salt in the way we think of the stuff on our kitchen table. It’s a naturally occurring mineral compound known as magnesium sulfate. It’s made of magnesium, sulfur, and oxygen. It got its name from a saline spring in Epsom, England, where the compound was first distilled way back in the 17th century.
The theory behind the epsom salt bath is relatively simple. When we drop these crystals into warm water, they dissolve and release magnesium and sulfate ions. Proponents of the practice suggest that these ions then travel through our skin and into our bloodstream, helping to correct the magnesium deficiencies that most of us are walking around with. It sounds great in theory, but the reality of our biology is a bit more complicated.
Our skin is essentially a high-security barrier. Its primary job is to keep things out—bacteria, toxins, and even excess water. It isn't a sponge that just soaks up whatever we submerge it in. For a mineral like magnesium to pass through this barrier, it needs to be in a form that is highly bioavailable, which is just a fancy way of saying "easy for our bodies to use and absorb."
The short answer is: maybe, but not as much as we’d hope. When we look at the clinical research, the evidence for magnesium sulfate (epsom salt) absorption through the skin is surprisingly thin. While some small studies have suggested a slight increase in magnesium levels after a week of daily soaking, many dermatologists and biochemists remain skeptical.
The main issue is the molecular structure. Magnesium sulfate is a relatively large molecule, and it doesn't always have the easiest time navigating the layers of our skin. Some researchers believe that if any absorption is happening at all, it’s likely occurring through our hair follicles or sweat glands, which act like tiny "back doors" into the body. However, the amount that actually makes it into our system during a quick 15-minute soak is often minimal.
Key Takeaway: While epsom salt baths feel incredible and can help with surface-level relaxation, they aren't the most efficient way to replenish our internal magnesium stores due to the low bioavailability of magnesium sulfate.
If we aren't getting enough magnesium from our baths, we might think the solution is to just pop a pill. But oral supplements come with their own set of headaches. Most oral supplements have to pass through our entire digestive tract, where a huge chunk of the mineral is lost before it ever reaches our cells.
Even worse, magnesium is a natural osmotic laxative. If we take too much at once, it draws water into the colon, leading to bloating, cramping, and... well, we all know where that ends up. This is why we’re such big fans of the transdermal (through the skin) approach. When we find a way to bypass the gut, we can get the nutrients we need without the digestive drama.
When we talk about whether we’re absorbing magnesium, we’re really talking about bioavailability. Not all magnesium is created equal. While epsom salt uses magnesium sulfate, there’s another player in the game that’s much better at getting past the skin’s bouncer: magnesium chloride.
At Flewd, we use magnesium chloride hexahydrate as the foundation for all our soaks. Why? Because it’s widely considered the most bioavailable form of magnesium for transdermal use. Unlike the sulfate form found in epsom salts, magnesium chloride is more stable and has a molecular structure that our skin finds much easier to process.
By choosing a form that our bodies can actually use, we ensure that the time we spend in the tub is actually doing something for our internal chemistry, not just giving us a few minutes of peace and quiet.
It’s helpful to understand why we’re so obsessed with magnesium in the first place. This mineral is a absolute workhorse. It’s involved in over 300 biochemical reactions in our bodies. It helps our muscles relax, keeps our heart rhythm steady, and plays a massive role in our nervous system's ability to handle stress.
The problem is that stress is a magnesium thief. When we’re stuck in "fight or flight" mode because of a looooong day at work or a stressful commute, our bodies burn through magnesium at an accelerated rate. We call this the "stress-mineral loop." We get stressed, we lose magnesium, and because we have less magnesium, our nervous system becomes even more reactive to stress.
Breaking that loop requires replenishing those stores effectively. If we’re just using a low-bioavailability salt, we might be relaxing the mind, but we aren't necessarily refilling the tank.
We realized early on that if we wanted to truly help people manage the physical symptoms of stress, we couldn't just stop at magnesium. Stress isn't one-size-fits-all. The way we feel when we’re anxious is totally different from the way we feel when we’re exhausted or just plain angry.
That’s why we created targeted formulas. We take that highly bioavailable magnesium chloride and pair it with specific vitamins, minerals, and nootropics (compounds that support brain function) to address specific stress symptoms.
When we soak in these nutrients, we’re bypassing the digestive system and delivering exactly what our cells are screaming for directly through the skin. It’s a 15-minute treatment that can provide benefits for up to five days.
We’ve established that the skin is a barrier, but it’s a permeable one. Transdermal delivery—which is just a fancy way of saying "absorbed through the skin"—is a well-established method in medicine. Think of nicotine patches or hormone creams. These work because the molecules are designed to sit on the skin and slowly migrate into the bloodstream.
When we soak in a warm (not hot!) bath, a few things happen that help this process along. First, the warm water increases blood flow to the surface of our skin. Second, the heat slightly dilates our pores and hair follicles. This creates the optimal environment for those magnesium chloride ions and vitamins to begin their journey inward.
This method is particularly effective for people who have sensitive stomachs or who struggle with the "laxative effect" of traditional magnesium pills. It’s a gentler, more holistic way to nourish the body. Plus, it turns a chore (supplementing) into a ritual (soaking).
We often think that if a warm bath is good, a scalding hot bath must be better. But if our goal is nutrient absorption, we actually want to keep the temperature in check.
If the water is too hot, we start to sweat. Sweating is an "exit-only" process for the skin. Our body is pushing fluids and toxins out to cool us down, which makes it much harder for minerals to move in. By keeping the water at a comfortable, warm temperature, we stay in "absorption mode." This allows the magnesium and vitamins in our Flewd Stresscare formulas to do their job effectively.
"A bath shouldn't feel like a survival challenge. Keeping the water warm rather than boiling ensures our skin stays receptive to the nutrients we're trying to give it."
While magnesium is the star of the show, we’ve found that it works better when it has a supporting cast. This is where the "science" part of Flewd Stresscare really kicks in. We use vitamins and nootropics to create a synergistic effect—meaning they work better together than they do alone.
For example, our Rage Squashing Soak uses chromium and vitamin B12. Chromium is a trace mineral that helps regulate blood sugar, which is often a hidden culprit behind irritability and "hangry" outbursts. When you pair that with the muscle-relaxing power of magnesium, you get a much more comprehensive approach to calming down than you would from a plain bag of epsom salts.
Our Sads Smashing Soak takes a similar approach by incorporating vitamins B3 and B6 along with nootropics. These are designed to support the neurotransmitters in our brain that regulate mood. By delivering these through the skin, we're providing a steady, gentle supply of what the body needs to find its balance again.
We know that our community cares about what they’re putting on their bodies—and what they’re washing down the drain. This is another area where traditional epsom salts can sometimes fall short. Many commercial bath salts are loaded with synthetic fragrances, artificial dyes, and anti-caking agents that aren't great for us or the planet.
We take a different route. Our formulas are 99% natural, non-toxic, and vegan. We’ve ditched the parabens and phthalates because we don't think "stress relief" should come with a side of endocrine disruptors.
Even our packaging is built with the future in mind. We use 100% PCR (post-consumer recycled) materials and biodegradable shipping supplies. Because let's be honest, worrying about the environmental impact of our self-care routine is just adding more stress to the pile, and we're trying to get rid of that.
One of the biggest mistakes we see people make is treating a magnesium soak like a "break glass in case of emergency" solution. We wait until we’re at a breaking point, take one bath, and expect to be "cured."
In reality, stress management is a cumulative process. Think of your body like a battery. A single soak might give you a 20% charge, but if you’re starting at zero, you’re still in the red. Regular use—about two to three times a week—helps build up those magnesium stores and keeps your nervous system on an even keel.
We’ve made this easier with our Stresscare Trio, like the Stresscare Trio or the Whole Mood Bundle. By having different formulas on hand, we can choose the soak that matches how we’re feeling in the moment. It turns self-care from a vague concept into a practical, repeatable ritual.
If you’ve spent any time in wellness circles, you’ve probably heard that epsom salt baths "draw toxins" out of the body. We’re gonna be real with you: that’s mostly marketing fluff.
Your liver and kidneys are your primary detox organs, and they’re very good at their jobs. A bath isn't going to "pull" heavy metals or toxins through your skin like a magnet. What a soak can do is support your body's natural systems. By replenishing magnesium and reducing stress, you’re helping your body function better overall. When we’re less stressed, our digestion improves, our sleep gets deeper, and our body is better able to handle its own natural detoxification processes.
We don't need to rely on fake science to justify a good soak. The real science—nutrient replenishment and nervous system regulation—is plenty impressive on its own.
It’s easy to lump our soaks in with the colorful, fizzy bath bombs you see at the mall. But there’s a massive difference between a bath bomb and a bath soak.
Bath bombs are designed for "the vibe." They’re about colors, glitter, and intense scents. While they can be fun, they often contain ingredients that can irritate sensitive skin or even cause yeast infections.
Our soaks are designed for the "effect." We’re not looking to turn your bathwater neon purple; we’re looking to get magnesium chloride, zinc, and B-vitamins into your system. We’ve focused on the most bioavailable ingredients and omitted the fillers. It’s the difference between eating a piece of candy and eating a nutrient-dense meal. Both have their place, but only one is actually going to help you feel better tomorrow morning.
At the end of the day, the question of whether your body absorbs magnesium from an epsom salt bath comes down to efficiency. Yes, you might get a tiny bit of magnesium from a traditional soak, but you’re mostly just enjoying a warm bath. If you’re serious about using transdermal therapy to manage stress, aches, or sleep, you need a form of magnesium that is built for the task.
By switching to magnesium chloride and incorporating targeted nutrients, we can transform a simple bath into a powerful tool for our mental and physical health. Stress is an inevitable part of modern life—our bodies treat an annoying Slack notification the same way they’d treat a predator in the wild. We can’t always control the stressors, but we can control how we replenish ourselves.
If you’re ready to stop making human soup and start actually replenishing your body, it’s time to upgrade your soak. We’ve done the science, so you can just focus on the soak.
"True stresscare isn't about escaping reality; it's about giving our bodies the resources they need to handle it."
For skin absorption, magnesium flakes (magnesium chloride) are generally superior to epsom salt (magnesium sulfate). Magnesium chloride is more bioavailable, meaning our bodies can absorb and use it more effectively through the skin. It is also less likely to dry out the skin during a long soak.
We recommend 15 to 20 minutes of soaking. This gives the warm water enough time to increase blood flow to the skin and allows the magnesium ions and other nutrients to begin passing through the skin barrier. There are diminishing returns after 30 minutes, so don't feel like you need to stay in until you’re a prune.
It is very difficult to "overdose" on magnesium through the skin. Our bodies are remarkably good at self-regulating transdermal absorption; they generally take in what they need and stop there. This is one of the biggest safety advantages of soaking versus taking high-dose oral supplements.
There’s no need to rinse off! In fact, we recommend towel-drying and letting the remaining minerals sit on your skin. Our formulas are non-toxic and designed to be skin-friendly, so leaving them on can actually extend the benefits. If you have extremely sensitive skin, a quick rinse with plain water is fine, but you’ll get the most out of it if you don't.
