14/05/2026
We’ve all been there. After a week that felt like a decade, we finally collapse into a tub of warm water, dump in a bag of Epsom salts, and hope for the best. It’s the age-old remedy for everything from a pulled hamstring to a bruised ego. But as we sit there among the dissolving crystals, a nagging question often floats to the surface: Is this actually doing anything for our internal chemistry, or are we just making human soup?
Specifically, we want to know if these baths are actually moving the needle on our magnesium levels. Magnesium is the "master mineral" that we desperately need for sleep, mood, and muscle recovery, yet most of us are running on empty. At Flewd Stresscare, we’re obsessed with the science of how nutrients get into our bodies because, frankly, we’re too tired for placebo wellness. We want things that work while we’re busy doing nothing in the tub.
In this guide, we’re gonna look at the data behind transdermal (through the skin) absorption. We’ll break down the difference between the salts our grandmas used and the modern science of magnesium chloride, and we’ll figure out if a 15-minute soak can really fix a week of high-cortisol chaos. It turns out, the answer is a little more nuanced than just "dump and soak," but relief is definitely within reach.
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To understand if our magnesium levels are actually going up, we have to look at what we’re putting in the water. Most people use "Epsom salt" as a catch-all term for bath salts, but there’s a massive chemical difference between the bag from the grocery store and a high-performance soak, something we break down in our guide to magnesium bath soak vs. Epsom salt.
Epsom salt is magnesium sulfate. It’s a naturally occurring mineral compound that was first discovered in Epsom, England, back in the 17th century. It’s made of magnesium, sulfur, and oxygen. While it’s been the gold standard for centuries, it’s not necessarily the most efficient way to get magnesium into our cells.
On the flip side, we have magnesium chloride. For a deeper dive into why it’s our preferred form, see our guide on best topical magnesium. Magnesium chloride is more "bioavailable," which is just a fancy way of saying our bodies can actually recognize and use it more easily. Think of it like this: if magnesium sulfate is a basic flip phone, magnesium chloride is the latest smartphone. They both do the job, but one is clearly faster and more capable.
When we talk about bioavailability, we’re talking about the percentage of a substance that actually makes it into our bloodstream and tissues. If we swallow a magnesium pill, it has to survive the "acid bath" of our stomachs and the complex filtration of our livers. Often, only a tiny fraction (sometimes as low as 4%) actually makes it to where it needs to go, which is why so many people turn to the best topical magnesium.
By using the right form of magnesium in a bath, we’re trying to bypass that digestive gauntlet. But for that to work, the mineral has to be soluble—meaning it has to dissolve completely and stay in a state that can slip through our pores. Magnesium chloride dissolves much more readily in water than magnesium sulfate, which is why it’s our go-to for deep replenishment.
For a looooong time, scientists were skeptical about whether we could absorb anything through our skin. The traditional view was that the skin is a "fortress" designed to keep things out. If it let everything in, we’d blow up like a balloon every time we went for a swim.
However, modern research has flipped that script. Our skin isn't a solid wall; it’s more like a smart filter. It’s covered in millions of tiny openings: pores, sweat glands, and hair follicles. Researchers have discovered that these hair follicles act like "tunnels" that allow certain minerals to bypass the tough outer layer of the skin, which is why transdermal magnesium uptake has become such an interesting topic.
Studies indicate that hair follicles and sebaceous (oil) glands are the primary pathways for magnesium ions. When we soak in a warm bath, our pores open up, and the concentration of magnesium in the water creates a "pressure" that encourages the ions to move into our skin. This process is called passive diffusion.
Key Takeaway: Our skin acts as a selective filter. While it blocks harmful toxins, it can allow essential minerals like magnesium to pass through via hair follicles and sweat glands, especially when the concentration in the water is high.
So, back to the big question: Do Epsom salt baths raise magnesium levels? The honest answer is that the science is still catching up to the anecdotal evidence, but the results we do have are promising.
The most famous study on this topic comes from the University of Birmingham. Researchers looked at 19 participants who soaked in magnesium sulfate baths for 12 minutes a day over the course of a week. The results showed that 17 out of the 19 people had a significant rise in their blood magnesium levels. Even more interesting? The people who didn't show a rise in their blood levels showed a rise in their urine levels, meaning the magnesium had definitely entered their system and was being processed by their kidneys.
While that study is great, it’s also small. Other scientists have pointed out that we need more large-scale, peer-reviewed trials to say for certain how much magnesium we absorb. Some dermatologists argue that the skin’s barrier is too tough for significant absorption.
However, we can't ignore the "feel-good" factor. Even if the exact milligram count of absorption is debated, the systemic effects are hard to deny. When we soak, we notice our heart rates slow down, our muscles stop twitching, and that "internal hum" of anxiety starts to fade. Whether that’s 100% magnesium absorption or a mix of heat therapy and mineral interaction, the result is a body that feels more regulated.
If you’ve ever taken a high-dose magnesium pill, you probably know about the "disaster pants" risk. Because the gut has a hard time processing large amounts of magnesium, it often reacts by drawing water into the colon. The result? An emergency trip to the bathroom.
This is where transdermal (through the skin) delivery wins every time. By soaking, we can get a much higher concentration of magnesium into our systems without upsetting our stomachs. It’s a more gentle, holistic way to top up our stores. Plus, it’s way more fun to sit in a warm bath than it is to choke down a giant horse pill.
We often treat stress like it’s just a "feeling" in our heads, but it’s actually a physical drain on our resources. When our nervous systems are stuck in "fight or flight" mode—treating a passive-aggressive email like a hungry lion—our bodies burn through magnesium at an alarming rate, which is why best magnesium for stress matters so much.
Magnesium is required to "turn off" the stress response. It helps regulate cortisol and supports the production of GABA, the neurotransmitter that tells our brains to chill out. But here’s the kicker: the more stressed we are, the more magnesium we lose. The more magnesium we lose, the more stressed we feel. It’s a vicious cycle that most of us are stuck in.
We believe that stress isn't a one-size-fits-all problem. Sometimes we’re "tired-wired" (anxious but exhausted), and other times we’re just physically beat up. That’s why we don't just stop at magnesium.
Every Flewd Stresscare soak starts with bioavailable magnesium—the most bioavailable form for your skin—but then we add specific nutrients to help break the cycle.
By delivering these nutrients through the skin, we’re essentially giving our bodies a "refuel" while we relax. It’s an efficient way to handle the physical side of stress so we can handle the mental side.
If we’re gonna take the time to draw a bath, we should probably do it right—how to use bath soak. You shouldn't just sprinkle a few crystals in and expect a miracle. There’s a bit of a science to getting the most out of your soak.
We want the water warm, not "surface of the sun" hot. If the water is too hot, our bodies start sweating profusely to cool down. While sweating is great for detoxing, it’s the opposite of what we want for absorption. We want the pores open and receptive, not pumping fluids out. Aim for roughly 92°F to 100°F.
It takes time for the ions to navigate the hair follicles and pores. Most research suggests that the "sweet spot" for absorption starts around the 15-minute mark, which lines up with how much bath soak to use. We recommend soaking for 20 to 30 minutes to get the full benefit.
If we’re using a high-quality magnesium soak, we should avoid using heavy soaps or bubble baths at the same time. These can create a film on the skin that blocks the magnesium from getting into those follicles. Save the suds for a different night, or wash off before you soak.
After you get out of the tub, just pat yourself dry with a towel. You don't need to rinse off in the shower. Leaving that mineral-rich water on your skin allows any remaining ions to continue absorbing as you cool down.
How do we know if we actually need more magnesium? Since 60% of the magnesium in our bodies is stored in our bones and the rest is inside our cells, a standard blood test often doesn't give the full picture. Our bodies will pull magnesium from our bones to keep our blood levels stable, so we might "test" fine even if our tissues are starving for it.
Instead of just looking at labs, we should look at how we feel. Common signs of deficiency include:
If we recognize these symptoms, it’s a sign our nervous systems are screaming for support, and that’s why magnesium soak benefits are worth keeping in mind. A consistent routine of magnesium-rich baths can help replenish those stores over time.
We aren't just another bath salt company. We started Flewd in 2020 during the height of the pandemic because we realized that the world was collectively losing its mind—and its magnesium. We wanted to create something that felt like a bridge between clinical science and the simple joy of a bath.
Our formulas are 99% natural, vegan, and biodegradable. We’ve ditched the synthetic fragrances and parabens that you find in grocery store salts because we don't think "self-care" should involve marinating in toxins. Instead, we use concentrated magnesium bath soaks built around magnesium chloride hexahydrate as our foundation.
When we use a Flewd Stresscare soak, we aren't just taking a bath. We’re giving ourselves a 15-minute transdermal nutrient treatment. Because the effects of a high-quality soak can last up to 5 days, it's not just about how we feel in the tub—it's about how we feel on Tuesday morning when the coffee machine breaks and the car won't start.
Consistency is what turns a nice bath into a legitimate stress-management tool. We don't need to live in the tub, but a regular rhythm helps.
Key Takeaway: You don't need to soak every day to see results. Because transdermal magnesium can stay in your system for several days, a 2–3 times per week routine is usually plenty to maintain healthy levels.
The truth is, we’re living in a world that is designed to deplete us. Our phones are constantly buzzing, the news is a lot, and we’re expected to be "on" 24/7. It’s no wonder our magnesium levels are in the basement, which is why magnesium chloride benefits can feel so helpful. We shouldn't feel guilty about being stressed; it’s a natural reaction to an unnatural environment.
Taking a bath can feel like a "luxury" we don't have time for, but we need to reframe it. It’s not an indulgence; it’s maintenance. It’s the easiest way to give our bodies the raw materials they need to keep us sane. We’re gonna be stressed anyway—we might as well have the nutrients to handle it.
So, do Epsom salt baths raise magnesium levels? Yes, they can—but they’re just the tip of the iceberg. While magnesium sulfate is a solid starting point, switching to a more bioavailable form like the best topical magnesium can make a world of difference in how much actually reaches your cells. By paying attention to water temperature, soak time, and the quality of your ingredients, you can turn a simple bath into a powerful tool for your wellness.
"Stress is a physical tax on the body, and magnesium is the currency we use to pay it. If we aren't replenishing our stores, we're going into 'health debt.' A transdermal soak is like a direct deposit for our nervous system."
Ready to move past basic bath salts? Explore our targeted stresscare soaks and find the formula that fits your specific brand of chaos. Whether you need to smash the "sads," crush a panic attack, or finally get some sleep, we’ve got a soak for that.
Most research suggests that to see an actual rise in magnesium levels, you need a fairly high concentration. We recommend using about 1 to 2 cups of Epsom salt for a standard-sized tub. If you’re using our concentrated Flewd packets, one packet is precisely measured to provide the optimal nutrient density for a single soak without the guesswork.
While it’s tempting to stay in until you’re a total raisin, you usually reach a point of diminishing returns after about 30 to 40 minutes. At that point, the water has cooled down, and your skin might start to dehydrate. Stick to 15–30 minutes for the best balance of absorption and skin health.
It depends on your goals, but many of us prefer the bath. Transdermal soaks bypass the digestive system entirely, allowing for higher doses without the laxative side effects.
Generally, magnesium baths for kids are considered safe and even beneficial for kids, as they can help calm the nervous system before bed. However, since kids have smaller bodies and more sensitive skin, it’s always best to start with a smaller amount of salt and check with your pediatrician first to ensure it's a good fit for them.
