Molekula
Magnesium stearate
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Magnesium stearate is a metallic soap used as a lubricant in pharmaceutical and cosmetic manufacturing. It is a white, odorless powder that improves flow properties in tablet and powder formulations. CAS: 557-04-0, Molecular Formula: [CH3(CH2)16CO2]2Mg, Molecular Weight: 591.24 g/mol, Storage: Ambient, Signal Word: Warning.
Molekula supplies Magnesium stearate at 4.0 - 5.0% purity (Mg) in 100 g and 500 g packs, from £35.40 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and safety data sheets are available in 6 languages. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
In stock — same-day dispatch
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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100 g — £29.50 per pack ex VAT · £35.40 inc. VAT
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500 g — £77.70 per pack ex VAT · £93.24 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Light fine powder |
| Water | ≤4.0% |
| Mesh | (1500) ≥98.0% |
| Free acid | ≤4.0% |
| Assay(Mg) | 4.0 - 5.0% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | Lumps |
| Odour | Odorless |
| Melting Point | 88 °C |
Source: PubChem CID 11177 (HSDB, ICSC)
Identification
| Property | Value |
|---|---|
| SKU | 17736814 |
| CAS Number | 557-04-0 |
| IUPAC Name | magnesium bis(octadecanoate) |
| EC Number | 209-150-3 |
| Molecular Formula | [CH3(CH2)16CO2]2Mg |
| Molecular Weight | 591.24 |
| Exact Mass | 590.5125 |
| SMILES | CCCCCCCCCCCCCCCCCC(=O)[O-].CCCCCCCCCCCCCCCCCC(=O)[O-].[Mg+2] |
| InChIKey | HQKMJHAJHXVSDF-UHFFFAOYSA-L |
| InChI | InChI=1S/2C18H36O2.Mg/c2*1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20;/h2*2-17H2,1H3,(H,19,20);/q;;+2/p-2 |
| PubChem CID | 11177 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 29157001 |
| Tariff Code | 2915705090 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H315 Causes skin irritation
- H319 Causes serious eye irritation
- H335 May cause respiratory irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+350 IF ON SKIN: Gently wash with soap and water
- P304+340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
- Dibasic magnesium stearate
- Magnesii stearas
- Magnesium distearate
- Magnesium octadecanoate
- Magnesium stearate g
- Octadecanoic acid, magnesium salt
- Petrac MG 20NF
- Stearic acid, magnesium salt
- Synpro 90
- Synpro Magnesium Stearate 90
Frequently asked questions
What is magnesium stearate used for?
Magnesium stearate is commonly used as a lubricant in pharmaceutical manufacturing and as a release agent in industrial processes.
What is the chemical formula and molecular weight of magnesium stearate?
The formula is [CH3(CH2)16CO2]2Mg with a molecular weight of 591.24 g/mol.
How should magnesium stearate be stored?
Store at ambient temperature, protected from moisture and direct sunlight.
What grade of magnesium stearate does Molekula supply?
Molekula supplies magnesium stearate as a light fine powder to the following specification: water ≤4.0%, mesh (1500) ≥98.0%, free acid ≤4.0% and magnesium assay 4.0–5.0%.
Can Molekula supply magnesium stearate in bulk?
Yes, Molekula can supply magnesium stearate in bulk quantities; please contact our sales team for pricing and availability.
What documentation comes with a magnesium stearate order?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS) upon request.
Where can I buy Magnesium stearate?
Directly from Molekula, which lists Magnesium stearate in 100 g and 500 g packs from £35.40 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.