Magnesium deficiency is something I’ve written about on more than one occasion over the years, and for good reason.
According to the FDA, 60% of the US population is deficient in magnesium - a critical nutrient required for over 300 enzymatic processes in the human body. 
I have to confess I have a major problem with these FDA recommendations.
It’s my professional opinion (and one that’s widely shared in the nutrition world) that the levels of magnesium the FDA considers “non-deficient” are woefully low and way below what should be considered “optimal”.
By my definition, close to 85% of the population would qualify as having sub-optimal levels of magnesium.
Getting your body to optimal levels of magnesium and allowing these enzymatic processes to run at full capacity can have profound effects on the health of your nervous and endocrine (hormone) systems.
There’s also some very cool functional applications for magnesium supplementation in acute muscle relaxation and improving sleep. More on this in a bit…
Why You’re Probably Magnesium DeficientThis simple answer to the question on why so many people are magnesium-deficient is “poor diets”, but this doesn’t tell the whole story.
The amount of magnesium found in our foods is ultimately dependent on how much magnesium is in the soil they're grown in, and almost all of our produce today is grown in soil that has been farmed for decades by industrial farming operations and is badly depleted of magnesium and other nutrients.
Farmers use fertilizers to replace the nutrients the plant needs to grow, but this is a far cry from growing plants in truly nutrient-rich healthy soil. As a result, most foods today contain less magnesium and other minerals than they did historically.
What Happens When You’re Magnesium Deficient
As I mentioned above, magnesium is a necessary co-factor for no less than 300 enzyme-driven processes in the body, so it stands to reason that when your magnesium levels are suboptimal, there will be consequences.
- Muscle Tension - Every time you think to move a muscle, it’s the movement of calcium and magnesium ions through the membranes in your muscle cells that make this movement happen at it's most basic level.
When you’re magnesium deficient, you won't have sufficient magnesium ions available in your muscles to allow for complete relaxation of the muscle after a contraction. Calcium accumulates in the cells, keeping the muscles in a semi-contracted state and chronic muscle tension results. 
- Headaches - As you probably know well, chronic muscle tension will lead to headaches. Beyond this, recent studies have found that magnesium deficiency is also a cause of non-tension migraine headaches. 
- Anxiety + Adrenal Dysfunction - A 2012 study detailed the connection between magnesium deficiency and chronic anxiety that doctors have observed for decades. Dysregulation of the hypothalamus-pituitary-adrenal axis (HPA axis) is often observed in cases of magnesium deficiency and researchers in this study noted that this HPA axis dysregulation was almost certainly the driver behind magnesium-related anxiety. 
- Insulin Resistance + Pre-Diabetes - Receptors for the hormone insulin on your muscle and liver cells require magnesium to function properly. Deficiency in magnesium will greatly reduce the sensitivity of your cells to this hormone. This increases risk for clinical “insulin resistance”, otherwise known as pre-diabetes. 
- Poor Sleep Quality - When the muscles are unable to relax completely and the adrenals are in a state of dysregulation, poor sleep quality is sure to result. It’s no surprise that this is one of the most common consequences of magnesium deficiency observed by physicians. 
Oral Magnesium or Transdermal?
The traditional way to address magnesium deficiency is through taking oral magnesium supplements.
While effective, there are limitations to this strategy. To fully address deficiency, magnesium needs to be delivered deep into muscle tissues throughout the body. While oral magnesium supplementation will achieve this eventually, it is quite slow, particularly when compared to transdermal supplementation.
I do still take an oral magnesium supplement daily, as I believe the absolute best strategy is to supplement both orally and transdermally. If you do take an oral supplement, choose one that is in chelated form (like magnesium glycinate) for maximum absorbability.
Why Transdermal Magnesium?If you choose only one type of magnesium supplement, transdermal is unquestionably the way to go. Here’s why:
- Superior Absorbability - When magnesium is absorbed via the skin, absorption considerably more efficiently than in the gut, where other nutrients often impair the uptake of magnesium. 
Muscle Relaxation - Perhaps the most compelling reason to use magnesium transdermally is the profound muscle relaxation it produces.
When magnesium is absorbed transdermally, it moves directly into the skin’s dense capillary network. From these dermal capillaries, movement into neighboring muscle tissue is efficient and rapid.
Whereas oral magnesium takes 45-90 minutes to reach skeletal muscle tissue and generally doesn’t penetrate very deeply, magnesium applied transdermally reaches the skeletal muscle tissue within minutes and produces a significant relaxing effect in the areas sprayed.
Improve Sleep Quality - Whether you’re aware of it or not - when you can’t sleep, the inability of your muscles to fully relax is playing a major role.
Using transdermal magnesium 20 minutes before bed will significantly improve sleep quality.
Transdermal Magnesium: The Options
1. Epsom Salt Bath - This is the classic “old school” route to get transdermal magnesium, and in many ways, still the best.
You will absorb huge amounts of magnesium over the course of a 15-20 minute bath, and because you’re immersed in the magnesium solution, the absorption will be well distributed throughout your body.
The recipe is simple: just dissolve 2-3 cups of epsom salts in a warm (but comfortable) bath and get in. 15-20 minutes is plenty to absorb huge amounts of magnesium into your skin and muscles.
If you’re in need of therapeutic muscle relaxation, an epsom salt bath is easily the best option. Realistically though, it’s not exactly convenient for most of us to prepare a bath and hang out in it for 20 minutes every day. Thankfully there's another option as of a few years ago...
2. Transdermal Magnesium Chloride Sprays - These magnesium spray products are relatively new to the market, and I couldn’t be happier to see them growing in popularity.
Transdermal magnesium sprays allow one to experience much of the absorption and muscle-relaxation benefits of epsom salt baths, but in an infinitely more convenient form.
At this point I’ve tried most of the transdermal magnesium products available, and the one I'm most sold on is this product from Ancient Minerals.
For a transdermal magnesium product to be fully effective, the magnesium must be fully infused - to the single-ion level - into the solution, otherwise it will simply sit on your skin and not absorb. This is what I believe sets this product apart.
Looking For More On Supplementation? Check out: