Pure USP Grade Magnesium Sulfate for relaxing bath soaks, soothing foot soaks, and garden plant care. Pharmaceutical-grade, fast-dissolving, third-party lab tested, and packaged at our FDA-registered facility in Madera, California.
Meets the strict purity and quality standards of the United States Pharmacopeia — the same grade used in pharmaceutical applications. Higher specification than hardware-store or agricultural grades.
Every batch is independently tested for purity and screened for heavy metal content, giving you confidence in what you're putting in your bath or on your skin.
Our smaller grain size dissolves quickly in warm water with no gritty residue — no stirring required, just add while the tub fills and it dissolves completely.
Magnesium sulfate sourced from within the United States and packaged at our FDA-registered facility in Madera, California. No overseas sourcing for your personal care products.
100% magnesium sulfate heptahydrate (MgSO₄·7H₂O) with no added fragrances, dyes, fillers, or preservatives. Safe for sensitive skin and compatible with essential oil customization.
The same pharmaceutical-grade product works in your bathtub and your garden bed. One versatile bag covers your relaxation routine and your magnesium-deficient tomatoes or roses.
Each pound of Epsom salt delivers approximately 9.8% elemental magnesium by weight, making it an efficient source of this essential mineral for both personal care and plant nutrition.
In addition to magnesium, Epsom salt contains approximately 13% elemental sulfur — a secondary macronutrient plants need for protein synthesis, enzyme function, and chlorophyll production.
Magnesium sulfate dissolves completely in water and is biodegradable. Safe for standard plumbing, septic systems, and the environment when used as directed.
Magnesium sulfate is a stable mineral compound that does not expire. Store in a cool, dry place in a sealed container and it remains effective indefinitely — no expiration date to worry about.
Epsom salt is magnesium sulfate heptahydrate (MgSO₄·7H₂O), a naturally occurring mineral compound first discovered in the town of Epsom, Surrey, England in the early 1600s. Despite its name, it is not a culinary salt — it's a pure mineral compound containing magnesium, sulfur, and oxygen bonded with seven water molecules.
USP Grade means our Epsom salt meets the rigorous purity, identity, and quality standards set by the United States Pharmacopeia. This pharmaceutical-grade designation ensures higher purity specifications than hardware-store or agricultural grades, rigorous testing for heavy metals and contaminants, and consistent quality batch after batch — making it the right choice for personal care and therapeutic use.
Epsom salt baths have been a popular relaxation and self-care ritual for generations. Many people find that soaking in warm Epsom salt water feels deeply soothing after exercise, physical work, or a long day. The warmth helps muscles relax, the mineral-rich water feels silky on skin, and the ritual itself can be a calming cornerstone of an evening wind-down routine.
| Chemical Name | Magnesium Sulfate Heptahydrate |
|---|---|
| Chemical Formula | MgSO₄·7H₂O |
| Grade | USP (United States Pharmacopeia) |
| Appearance | White crystalline granules |
| Elemental Magnesium | ~9.8% by weight |
| Elemental Sulfur | ~13% by weight |
| Solubility | Highly water-soluble (fast-dissolving) |
| Source | United States |
| Packaged At | Madera, California (FDA-registered facility) |
| Testing | Third-party lab tested, heavy metal screened |
| Shelf Life | Indefinite when stored properly |
Our Epsom salt is fragrance-free by design — this lets you customize your experience. Add 10–15 drops of Lavender Essential Oil for a calming evening soak, 5–8 drops of Peppermint Essential Oil for a cooling, invigorating post-workout soak, or 8–12 drops of Eucalyptus Essential Oil for a spa-like steam experience. Always add essential oils after you're in the tub (not while water is running) for best aroma retention.
Epsom salt provides two essential plant nutrients: magnesium — the central atom of every chlorophyll molecule — and sulfur, which supports protein synthesis, enzyme activation, and nutrient uptake. When plants are genuinely deficient in magnesium, Epsom salt is one of the fastest-acting, most affordable corrections available.
| Method | Amount | Frequency | Notes |
|---|---|---|---|
| Foliar Spray | 1 tbsp per gallon of water | Every 2 weeks | Apply early morning or evening; avoid midday heat |
| Soil Application | 1 tbsp per foot of plant height | Monthly during growing season | Work into soil around base; water thoroughly |
| Transplant Drench | 1 tbsp per gallon of water | At planting time | Water seedlings with solution to reduce transplant stress |
| Lawn Care | 3 lbs per 1,250 sq ft | Spring and fall | Broadcast spread then water in thoroughly |
Magnesium-hungry plants that often respond well to Epsom salt supplementation include tomatoes, peppers, roses, potatoes, carrots, citrus trees, and leafy greens. Always observe your specific plants and conditions — healthy plants with adequate soil magnesium generally don't need additional supplementation.
| Feature | Epsom Salt (Ours) | Magnesium Chloride | Magnesium Citrate |
|---|---|---|---|
| Chemical Name | Magnesium Sulfate | Magnesium Chloride | Magnesium Citrate |
| Best For | Bath soaks, garden use | Oral supplements, topical oil | Oral supplements |
| Bath / Soak Use | ✓ Excellent | ✓ Good (bath flakes) | ✗ Not typical |
| Garden Use | ✓ Excellent | ✗ Not recommended | ✗ Not recommended |
| Contains Sulfur | ✓ Yes (~13%) | ✗ No | ✗ No |
| Oral Supplement Use | ✗ Not recommended | ✓ Yes (USP grade) | ✓ Yes |
| Dissolves Easily | ✓ Yes (fine grain) | ✓ Yes | Varies by form |
Refer to the Safety Data Sheet (SDS) for complete safety information.
Epsom salt is a great foundation — these complementary products let you build a complete at-home wellness and magnesium routine.
Fast-absorbing topical magnesium chloride for direct, targeted application — no bath required.
Pharmaceutical-grade magnesium chloride powder for oral supplementation or DIY magnesium oil and bath flakes.
Large flake format of magnesium chloride — a popular Epsom salt alternative for bath soaks with a silky texture.
Explore both Epsom salt and magnesium chloride bath formats together — great for finding your preferred soak experience.
The classic bath oil pairing — calming, floral aroma for evening wind-down soaks. Use 10–15 drops per bath.
Fresh, cooling aroma popular for spa-style steam experiences and congestion relief. Use 8–12 drops per bath.
Invigorating and cooling — excellent for post-workout soaks and foot soaks. Use 5–8 drops per bath.
Bright, uplifting citrus aroma for morning or mood-boosting baths. Use 10–15 drops per bath.
For a standard bathtub (approximately 40 gallons), use 2 cups (about 400g) of Epsom salt. Add it while the water is running for best dissolution. For a large garden tub (60+ gallons), use 3 cups. For a lighter soak, 1.5 cups works well. See our complete guide: How to Bathe in Epsom Salt.
Many people enjoy Epsom salt baths 2–3 times per week as part of their self-care routine. There's no strict limit for healthy adults using it externally. If you have any medical conditions or skin sensitivities, check with your healthcare provider for personalized guidance.
Yes. Our Epsom salt is sourced from the United States and packaged at our FDA-registered facility in Madera, California. Every batch is third-party lab tested for purity and heavy metal content before it ships.
No. Magnesium sulfate is a stable mineral compound that does not expire. Store it in a cool, dry place in an airtight container to prevent moisture absorption and clumping — but it won't lose effectiveness over time.
They are completely different compounds. Epsom salt is magnesium sulfate (MgSO₄·7H₂O), while table salt is sodium chloride (NaCl). Epsom salt contains magnesium and sulfur; table salt contains sodium and chlorine. They cannot be substituted for each other in any use case.
Yes — this is a popular and easy way to customize your bath experience. Add the essential oil after you've entered the tub for best aroma. Popular choices include Lavender (10–15 drops for relaxation), Peppermint (5–8 drops for cooling), and Eucalyptus (8–12 drops for a spa feel).
No. Our Epsom salt dissolves completely in bath water and is safe for standard plumbing and septic systems when used as directed. It's also biodegradable and environmentally benign at normal bath-use concentrations.
Yes, when used appropriately. Epsom salt delivers magnesium and sulfur — two plant nutrients — and works well for plants showing signs of magnesium deficiency. However, only apply it when there's a genuine deficiency. Excess magnesium can interfere with calcium uptake. See our full gardening tips in the Garden & Plant Care section, and our article on 8 Useful Epsom Salt Hacks for more ideas.
Our USP Grade Epsom salt is pure magnesium sulfate with no added fragrances, dyes, or preservatives — making it a good choice for sensitive skin compared to scented bath products. If you're new to Epsom salt baths, start with a smaller amount (1 cup instead of 2) to test your reaction. Discontinue if any irritation occurs.
Greenway Biotech, Inc. has been a family-owned fertilizer and wellness company since 1989. We relocated our operations to Madera, California to be closer to the agricultural communities in the San Joaquin Valley that rely on our products. Our FDA-registered facility, third-party testing program, and commitment to accurate, educational content reflect our belief that customers deserve to know exactly what they're buying and why it works.
Check out our full FAQ page or contact our experts for personalized advice.
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