Magnesium Chloride USP — Dead Sea Pharmaceutical Grade
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Greenway Biotech · Made in California since 1989
USP Grade. Dead Sea sourced.
One powder for your whole magnesium routine.
Pharmaceutical-grade Magnesium Chloride Hexahydrate, 99.9% pure, repackaged from Dead Sea brine. Edible and versatile — mix an oral solution, blend your own magnesium oil, or add to a bath or foot soak. One bag covers all three, with a third-party Certificate of Analysis to back it up.
Find your size → See how to use itShips from California · 90-day guarantee · Lab documents below
99.9%
USP-grade purity
~12%
Elemental Mg by weight
3uses
Oral, topical, and bath
35+yrs
Family-owned in California
01 / Choose your size
Right-sized for your routine.
Durations below assume a daily oral serving of 45 ml from the standard 33 g/liter preparation (~180 mg elemental Mg per serving). Bath and DIY-oil use will draw the bag down faster.
| Size | Typical Duration | Uses per Container | Best For |
|---|---|---|---|
| 1 lb | ~4-5 months daily oral use | ~13 liters of prepared solution | Best starter size |
| 2 lb | ~8-10 months daily oral use | ~27 liters of prepared solution | Established routines |
| 4 lb | ~16-20 months daily oral use | ~54 liters of prepared solution | Multi-person households |
| 8 lb | ~32-40 months daily oral use | ~108 liters of prepared solution | Best value |
| Product Type | USP-grade Magnesium Chloride Hexahydrate powder — edible, suitable for oral solution and topical use |
|---|---|
| Chemical Form | MgCl₂·6H₂O (Magnesium Chloride Hexahydrate) |
| Key Ingredient | Magnesium Chloride Hexahydrate (MgCl₂·6H₂O) — ~12% elemental magnesium by weight |
| Source / Origin | Dead Sea mineral brine, refined to USP specifications |
| Grade / Purity | USP Pharmaceutical Grade — 99.9% minimum purity |
| Free From | No fillers, anti-caking agents, flow aids, or artificial additives |
| Vegan | Yes — mineral salt, no animal-derived inputs |
| Typical Duration | 1 lb provides ~4-5 months of daily oral use at the standard serving |
| Containers | Use glass, ceramic, or food-grade plastic only — avoid metal |
| Testing | Independently tested for heavy metals; results consistently well below required limits; COA available |
| Safety | Consult a healthcare provider before oral use if pregnant, nursing, or on medications |
02 / Ideal for
One powder.
Many routines.
Designed for people who want pharmaceutical-grade flexibility — oral solution, magnesium oil, and bath soak from a single USP-grade source.
Oral Magnesium
For preparing a clean, USP-grade oral magnesium solution at home — popular among shoppers who prefer to mix their own rather than buy pre-formulated liquids or capsules.
DIY Magnesium Oil
For mixing your own topical magnesium spray or roll-on at a lower cost per ounce than ready-made bottles — and with full control over concentration.
Baths & Foot Soaks
A relaxing evening wind-down ingredient on its own, or combined with Epsom Salt for a layered magnesium soak — fits naturally into evening routines.
DIY Formulators
For anyone building their own bath salts, topical sprays, or wellness recipes — USP raw material with a Certificate of Analysis behind every batch.
Evening Wind-Down
Many shoppers take their magnesium solution or do a foot soak 30-60 minutes before bed as part of a consistent evening routine.
Multi-Method Users
If you want oral, topical, and bath all from the same trusted bag — instead of three separate products — this is the one to keep on hand.
03 / Why this one
The USP standard.
The Dead Sea source.
A few attributes set this apart from generic flake or industrial-grade magnesium chloride — and from most consumer wellness products on the shelf.
USP
Pharmaceutical-grade purity.
Meets United States Pharmacopeia standards for identity, purity, and quality — specifications more stringent than typical food-grade material. USP grade defines what the material is; the Certificate of Analysis confirms that each batch meets the spec.
🌊
Sourced from the Dead Sea.
Refined from the mineral-dense brines of the Dead Sea, a source long associated with high natural magnesium content and wellness traditions. The same starting material is used in pharmaceutical and food applications worldwide.
🇺🇸
Hand-bottled in Madera, California.
Repackaged in our family-operated FDA-registered facility in Madera, with quality checks at every stage from receiving to final packaging. The same facility handles our full line of fertilizer and wellness products under consistent quality controls.
⚗️
Third-party lab tested.
Each batch is independently tested for heavy metals and compliance with USP specifications. Results are consistently well below required limits. A Certificate of Analysis is available — linked in the Documents section below.
✨
Nothing added.
No anti-caking agents, no flow aids, no artificial additives or preservatives — just Magnesium Chloride Hexahydrate. The same powder works for oral solution, DIY topical oil, and bath soaks without compromise.
🌱
Vegan and shelf-stable.
A mineral salt — no animal-derived inputs at any stage. Stored dry and sealed, the powder is stable indefinitely; it is hygroscopic and may clump if exposed to humid air, which does not affect quality.
04 / The science
Why hexahydrate, and what "USP" really means.
~12% elemental Mg
Magnesium Chloride Hexahydrate (MgCl₂·6H₂O)
Magnesium Chloride is an inorganic salt composed of magnesium and chloride ions. In its hexahydrate form (MgCl₂·6H₂O), each unit is associated with six water molecules — a crystal structure that dissolves cleanly in water and produces a clear, sediment-free solution. It is the standard form used for both oral supplementation and topical magnesium applications in pharmaceutical and food settings worldwide.
Every magnesium compound carries a different percentage of actual (elemental) magnesium. For Magnesium Chloride Hexahydrate, the math is fixed by molecular weight: elemental Mg (24.305 g/mol) divided by MgCl₂·6H₂O (203.31 g/mol) equals approximately 11.96%, or about 120 mg of elemental magnesium per gram of powder. Every serving figure on this page is derived from that same calculation.
"USP grade" means the material meets United States Pharmacopeia specifications — tighter impurity limits and batch-level testing for heavy metals and contaminants than typical food-grade material. It is a purity standard, not a use designation; the Certificate of Analysis confirms each batch meets the spec.
For a deeper comparison of how this form fits into broader magnesium routines, see Magnesium Chloride Benefits: What It Does, Why It Works, and How to Use It.
Key Ingredients
One ingredient — that is the point. This is not a formulated supplement; it is a single, traceable raw material.
Magnesium Chloride Hexahydrate (MgCl₂·6H₂O)
The only ingredient. USP grade, 99.9% minimum purity, sourced from Dead Sea brine and refined to pharmacopeial specifications. ~12% elemental Mg by weight; CAS 7791-18-6.
Allergen note: Contains no common food allergens, no gluten, no soy, no dairy. As with any supplement or topical, patch test on a small skin area before broader use; discontinue if irritation occurs.
Technical Snapshot
| Chemical Name | Magnesium Chloride Hexahydrate |
|---|---|
| Chemical Formula | MgCl₂·6H₂O |
| Molecular Weight | 203.31 g/mol |
| Elemental Mg Content | ~11.96% by weight (24.305 / 203.31) |
| Grade | USP (United States Pharmacopeia) |
| Purity | 99.9% minimum |
| Source | Dead Sea mineral brine |
| Appearance | White crystalline flakes or powder; hygroscopic |
| Solubility | Highly soluble in water; dissolves clear with no sediment |
| Standard Preparation | 33 g per 1 liter of water → ~3.95 mg elemental Mg per ml |
| Typical Daily Serving | 45 ml of prepared solution → ~180 mg elemental Mg |
| Safe Containers | Glass, ceramic, or food-grade plastic only — never metal |
| Packaged At | Greenway Biotech facility, Madera, California |
| Testing | Third-party lab tested; heavy metal screened |
| CAS Number | 7791-18-6 |
What to Expect
First use: The powder dissolves quickly and completely in water; the oral solution has a mildly salty-bitter flavor that mixes well into juice or flavored water. Topical magnesium oil may produce a mild tingling sensation on first applications, especially on sensitive skin.
Week 1-2: Many shoppers report changes in sleep quality, evening wind-down, or muscle comfort within 1-2 weeks of consistent use. Topical tingling typically fades as skin adjusts.
Month 1+: More gradual benefits related to overall magnesium status may take several weeks to a few months. Individual experience varies with baseline magnesium intake, diet, and consistency of use.
05 / How to use
Pick your method.
Get the amount.
Three approved methods — oral solution, bath/foot soak, and DIY magnesium oil. All amounts trace to the elemental math in the Science section above. Always follow the directions printed on your bag.
Oral Magnesium Solution
Quick answer: Dissolve 33 g in 1 liter of water; take 45 ml (~1.5 oz) once daily for ~180 mg of elemental magnesium.
- Dissolve 33 grams (approximately 5 level teaspoons) of Magnesium Chloride USP in 1 liter of water in a glass container.
- Stir until completely dissolved — usually under a minute.
- Take 45 ml (about 1.5 oz) once per day, or as directed on the bag label or by your healthcare provider.
- One 45 ml serving provides approximately 180 mg of elemental magnesium — roughly half the typical daily target for most adults (310-420 mg RDA).
Quick Dose Reference — Stirring Directly Into a Drink
If you would rather skip the pre-mixed liter and stir a measured amount into a glass of juice, water, or any non-carbonated drink, the powder dissolves in seconds. Flavor is mildly salty-bitter at higher amounts — orange juice masks it well.
| Powder Amount | Approx. Elemental Mg | Notes |
|---|---|---|
| ¼ teaspoon (~1.5 g) | ~180 mg elemental Mg | Equivalent to the standard 45 ml daily serving |
| ½ teaspoon (~3 g) | ~360 mg elemental Mg | Within the typical adult daily target (310-420 mg RDA) |
| ¾ teaspoon (~4.5 g) | ~540 mg elemental Mg | Above the typical daily target — use only under professional guidance |
Figures assume Magnesium Chloride Hexahydrate is ~12% elemental magnesium by weight. Teaspoon volume varies slightly with powder settling — a kitchen scale is more reliable for precise dosing.
Tip: Many shoppers take their magnesium solution in the evening as part of a wind-down routine — 30 to 60 minutes before bed is common. If you are sensitive to magnesium, start with a smaller serving and increase gradually. For background, see Oral vs Transdermal Magnesium: Complete Guide.
Baths & Foot Soaks
Quick answer: ½-1 cup in a warm bath, or ¼-½ cup in a foot-soak basin. Soak 20-30 minutes.
| Use | Amount | Notes |
|---|---|---|
| Full Bath | ½ to 1 cup | Warm (not hot) bathwater; soak 20-30 minutes |
| Foot Bath | ¼ to ½ cup | A basin of warm water deep enough to cover the feet |
| Combination Soak | Combine with Epsom Salt | A layered routine — both magnesium forms in one bath |
Tip: An evening foot soak 30-60 minutes before bed is a popular wind-down routine. For step-by-step bath guidance, see How to Bathe in Epsom Salt — the same principles apply to magnesium chloride.
DIY Magnesium Oil
Quick answer: Equal parts Magnesium Chloride USP powder and warm distilled water — store in a glass spray bottle.
- Heat ½ cup of filtered or distilled water until warm but not boiling.
- Pour the warm water over ½ cup of Magnesium Chloride USP in a glass container.
- Stir until completely dissolved and let cool to room temperature.
- Transfer to a glass spray bottle (never metal).
- Spray onto arms, legs, or the soles of the feet and massage in. Use 5-10 sprays per application area.
Tip: If the spray tingles, dilute with more water. For a full walkthrough, see How to Make Magnesium Oil Using Magnesium Chloride or the related Benefits of Magnesium Oil on Feet guide.
06 / Directions
Mix it.
Use it.
Make it routine.
Whatever method you choose, consistency tends to matter more than the exact amount. Always follow the directions on the bag label.
-
01
Start with the bag label.
The printed directions on your bag are the primary reference. The methods on this page mirror those directions and offer practical context for each.
-
02
Start low if you are new.
If this is your first time, begin with a smaller serving — about half the standard amount — and adjust over a week or two. Sensitivity varies, and a gradual ramp is the most comfortable approach.
-
03
Use the right containers.
Glass, ceramic, or food-grade plastic only — magnesium chloride is corrosive to metal. Never use a metal spoon, bowl, or spray bottle when mixing or storing.
-
04
Keep it consistent.
Many shoppers find the most useful pattern is daily, in the evening, as part of a wind-down routine. Whether oral, topical, or bath, regular use tends to outperform sporadic large doses.
Good to Know
If you are pregnant, nursing, taking medications, or managing a kidney or cardiovascular condition, consult your healthcare provider before starting an oral magnesium routine. For topical and bath use, discontinue if skin irritation occurs.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
07 / Compare
Five forms.
Different routines.
Different magnesium forms suit different goals. Here is a general orientation — not a ranking.
| Form | Typical Use | General Tolerance | Best For | Notes |
|---|---|---|---|---|
| Magnesium Chloride USP (this product) | Oral solution, magnesium oil, foot soaks | Generally gentle when dosed appropriately | Multi-method users — one bag covers oral, topical, and bath | Highly soluble; ~12% elemental Mg; hexahydrate form |
| Magnesium Chloride Bath Flakes | Bath soaks, foot soaks, DIY oil | Topically well tolerated | Soaking routines | Food-grade flakes — external use only, no oral content |
| Magnesium Oil Spray | Ready-to-use topical spray | May tingle on first uses | Fast, no-mix topical routines | Pre-mixed USP-grade solution in a glass bottle |
| Magnesium Cream | Moisturizing topical massage | Gentle on dry skin | Daily skin and massage routines | Magnesium chloride blended with shea, coconut, beeswax |
| Epsom Salt (Magnesium Sulfate) | Bath soaks; secondary plant nutrient | Topically well tolerated | Classic bath ritual + garden use | Different chemistry (MgSO₄·7H₂O); ~10% elemental Mg |
08 / Decision
Is this the right
magnesium for you?
A short fit-check so you can decide quickly.
A Great Fit If You
- Want pharmaceutical-grade (USP) raw material with a Certificate of Analysis
- Plan to prepare your own oral magnesium solution at home
- Want to make DIY magnesium oil at a lower cost per ounce than ready-made spray
- Prefer one versatile powder that covers oral, topical, and bath uses
- Appreciate Dead Sea sourcing and a clean, single-ingredient formula
- Want a long-shelf-life supply you can use across a year or more
Consider Another Option If
- You want zero mixing — try the ready-made Magnesium Oil Spray instead
- You prefer a moisturizing cream for daily massage — see Magnesium Cream
- You only need bath flakes for soaks — try Magnesium Chloride Bath Flakes (external use only)
- You want the classic bath-salt experience — try Epsom Salt
- You want a one-stop shop of all three bath forms — see the Magnesium Bath Salts Bundle
09 / Build the routine
Start with the powder.
These complete the routine.
Many shoppers build a layered magnesium routine — oral solution from this powder, plus a ready-made topical and a bath form.
Topical
Magnesium Oil Spray
Ready-to-use USP-grade magnesium chloride spray in a glass bottle — no mixing. A convenient post-workout or pre-bed topical.
SkincareMagnesium Cream
Moisturizing cream blended with magnesium chloride, shea butter, coconut butter, and beeswax. For targeted massage and daily use.
Bath SoakEpsom Salt (Magnesium Sulfate)
The classic bath soak. Combine with Magnesium Chloride USP in one tub for a layered magnesium routine — two forms in a single soak.
Bath SoakMagnesium Chloride Bath Flakes
Larger-format magnesium chloride flakes for bath and foot-soak use — easier to scoop than fine powder. External use only.
10 / Safety & handling
Read this before
you mix.
A short safety summary covering oral, topical, and storage. Keep out of reach of children and pets.
- Consult your healthcare provider before oral use if pregnant, nursing, taking medications, or managing a kidney or cardiovascular condition. Do not exceed the recommended serving without professional guidance.
- Patch test before broad topical use. Apply a small amount to the inner forearm and wait 24 hours. Discontinue if redness, irritation, or discomfort occurs. Avoid contact with eyes and mucous membranes.
- Container rule: glass, ceramic, or food-grade plastic only — magnesium chloride solution is corrosive to metal. Wear gloves when handling large quantities of dry powder.
- Storage: keep the bag sealed tightly after each use. The powder is hygroscopic and may clump if exposed to humid air — quality is unaffected. Store prepared oral solution in a sealed glass container at room temperature, away from direct sunlight.
- First aid: for skin contact, rinse with water if irritation occurs. For eye contact, rinse immediately with plenty of water and seek medical attention if irritation persists. For ingestion of large amounts, seek medical advice or contact Poison Control.
11 / FAQ
Common questions.
Honest answers.
If your question is not here, contact our team at questions@greenwaybiotech.com.
What is Magnesium Chloride Hexahydrate?
Magnesium Chloride Hexahydrate (MgCl₂·6H₂O) is a highly soluble form of magnesium that includes six water molecules in its crystal structure. This makes it dissolve quickly and cleanly in water, which is why it is the standard pharmaceutical-grade form used for both oral solutions and topical magnesium applications worldwide.
Is this Magnesium Chloride safe to take orally?
This product is USP grade and edible. Always follow the directions printed on your bag, and use only the recommended serving unless directed otherwise by a healthcare provider. If you have kidney disease, cardiovascular conditions, are pregnant, nursing, or take medications, consult your healthcare provider before starting an oral magnesium routine.
What is the recommended oral preparation and serving?
A common preparation is to dissolve 33 grams in 1 liter of water and take 45 ml (about 1.5 oz) per day, which provides approximately 180 mg of elemental magnesium. The typical adult daily intake target is 310-420 mg, so one serving covers roughly half. Your healthcare provider can help you decide what is appropriate for your situation.
Can I use this to make magnesium oil at home?
Yes. Mix equal parts Magnesium Chloride USP powder and warm distilled water, stir until dissolved, let cool, and store in a glass spray bottle. If you prefer a ready-made option with no mixing, see our Magnesium Oil Spray. For a step-by-step DIY guide, see How to Make Magnesium Oil Using Magnesium Chloride.
Why does topical magnesium sometimes feel tingly?
A mild tingling sensation when applying magnesium oil or concentrated solutions to the skin is common and typically fades with regular use as the skin adjusts. It tends to be more noticeable on sensitive areas, freshly shaved skin, or dry skin. Starting on the soles of the feet — where skin is thicker — is a common way to ease in. If tingling is uncomfortable, dilute with more water.
How long does one liter of prepared oral solution last?
At the standard preparation of 33 g per liter and a daily serving of 45 ml, one liter lasts approximately 22 days. A 1 lb bag prepares enough solution for roughly 4-5 months at that pace; an 8 lb bag covers a household for two to three years of daily use.
Why should I avoid metal containers?
Magnesium chloride solution is corrosive to many metals and can stain or contaminate your solution. Use glass, ceramic, or food-grade plastic for mixing, storage, spray bottles, and any spoons or scoops. Stainless steel utensils used briefly to scoop dry powder are generally fine, but long-contact metal storage is not.
Can I use both oral and topical magnesium together?
Many shoppers do. Oral magnesium supports whole-body intake, while topical applications offer a localized, skin-surface routine that bypasses the digestive system. Introduce changes gradually and consult a healthcare professional if you have questions about total intake. For a deeper comparison, see Oral vs Transdermal Magnesium.
How long does it take to notice a difference?
Many shoppers report changes in sleep quality, evening wind-down, or muscle comfort within 1-2 weeks of consistent use. More gradual benefits related to overall magnesium status may take several weeks to a few months. Individual experience varies based on baseline intake, diet, and consistency. For context on signs of low intake, see How to Know If You're Magnesium Deficient.
What is the difference between this and Magnesium Chloride Bath Flakes?
This product is USP pharmaceutical grade and is suitable for oral, topical, and bath use. Our Magnesium Chloride Bath Flakes are food-grade and intended for external use only — bath soaks, foot soaks, and DIY magnesium oil. The flakes are a larger-format crystal that is easier to scoop for bathing; this USP powder gives you the option of oral preparation as well.
What does "USP grade" actually mean?
USP (United States Pharmacopeia) grade is a purity standard. A USP-grade material meets pharmacopeial specifications for identity, purity, and contaminant limits — generally tighter than typical food-grade specifications. It does not, by itself, mean the product is a dietary supplement; it means the raw material is pharmaceutical-grade quality. The Certificate of Analysis confirms each batch meets the spec.
Does the powder expire or go bad?
Magnesium chloride is a stable mineral salt that does not expire when stored properly. Keep the bag sealed in a cool, dry place. The powder is hygroscopic — it can absorb moisture from humid air and may clump — but this does not affect quality. Break up clumps and use as normal.
Ready to start?
Pick your size. We'll ship it.
Available in 1 lb, 2 lb, 4 lb, and 8 lb. Ships from our family-operated facility in Madera, California. Backed by our 90-day money-back guarantee — if it is not the right fit, we will make it right.
Choose your size →Ships from California · 90-day guarantee · Lab documents above