
Selenium is one of those trace minerals the human body cannot manufacture on its own — yet it quietly powers glutathione peroxidase, the enzyme system that defends every cell against oxidative stress. Nature’s elegant answer is L-selenomethionine: a single selenium atom slipped precisely into the backbone of the essential amino acid methionine, exactly as it appears in grains, legumes, and Brazil nuts. But here lies the paradox — pure L-selenomethionine carries roughly 40% elemental selenium by weight, a concentration far too potent for practical, safe dosing. Our answer is precision dilution: we blend purified L-selenomethionine onto a dicalcium phosphate (DCP) carrier at a standardized 0.5% ratio, bringing elemental selenium down to a safe, manageable 2,000 ppm. The result is a white to off-white fine powder engineered for microgram-accurate fortification of dietary supplements and animal feed premixes — organic selenium in its most bioavailable amino acid form, without the handling hazards of concentrated selenium compounds.
| Item | Specification |
| Product Name | L-Selenomethionine Powder 0.5% |
| CAS Number | 3211-76-5 |
| Molecular Formula | C₅H₁₁NO₂Se |
| Molecular Weight | 196.11 g/mol |
| IUPAC Name | (2S)-2-Amino-4-(methylselanyl)butanoic acid |
| Active Loading | ≥ 0.5% (≡ 5,000 ppm selenomethionine) |
| Elemental Selenium | ≥ 0.20% (≡ 2,000 ppm Se) |
| Carrier | Dicalcium Phosphate (DCP) |
| Appearance | White to Off-White Fine Powder |
| Solubility of Active | L-Selenomethionine is soluble in water; the composite powder disperses in aqueous media |
| Loss on Drying | ≤ 5.0% |
| Heavy Metals (Pb) | ≤ 5 ppm |
| Arsenic (As) | ≤ 2 ppm |
| Mesh Size | 80 – 100 Mesh |
| Production Method | Chemical synthesis / Fermentation → Dilution on DCP carrier |
| Grade | Food Grade / Feed Grade |
| Shelf Life | 24 Months (store ≤ 25°C, away from light, sealed) |
Long before humans learned to fortify with selenium, plants were mastering the chemistry. In selenium-rich soils, legumes and grains absorb the mineral and guide it into methionine’s molecular framework, producing L-selenomethionine — nature’s chosen storage form of organic selenium. This is the same molecule our powder delivers, built by the same biochemical pathway that fills Brazil nuts with selenium.
What distinguishes this product from a simple mineral salt is precisely this molecular design: the selenium atom is covalently bound inside an amino acid, mirroring how the element travels through the natural food chain — a form the body recognizes, absorbs, and utilizes on familiar terms.
Consider the numbers: pure selenomethionine is roughly 40% elemental selenium — about 400,000 ppm. A single mis-measured gram could push an entire batch past safe limits. By dispersing the active onto DCP at 0.5%, we bring selenium down to 2,000 ppm: concentrated enough for efficient formulation, dilute enough for safe, accurate microgram-level dosing.
The dilution is not an afterthought — it is the safety feature. Every 1 kg of this powder delivers exactly 2,000 mg of elemental selenium in a fully predictable, reproducible ratio, batch after batch.
L-selenomethionine is produced by chemical synthesis or fermentation — selenium substituted for sulfur along the methionine pathway — then purified to high concentration by crystallization. Finally, the pure active is precision-blended with food-grade DCP to a uniform 0.5% homogeneity across the entire lot.
Every batch is verified by ICP-MS or AAS for total selenium content and by HPLC for selenomethionine identity, so the specification you approve is exactly the specification you receive.
One atom makes the difference: L-selenomethionine differs from methionine by a single selenium-for-sulfur substitution. It is the dominant organic selenium species in plant and animal foods — chemically distinct from inorganic salts like sodium selenite and sodium selenate.
The 0.5% DCP pre-dilution brings elemental selenium from a hazardous ~400,000 ppm down to a manageable 2,000 ppm — enabling accurate microgram-scale dosing with zero concentrated-selenium handling risk.
A single, chemically defined molecule with a unique chromatographic retention time — analytically distinguishable from selenium yeast’s undefined mixtures and fully traceable from batch to batch.
Dicalcium phosphate is the industry-standard premix excipient — free-flowing, compatible with other vitamins and minerals, and stable alongside co-formulated micronutrients through shelf life.
| Product Name | L-Selenomethionine Powder 0.5% | Batch No. | DMT20260715 |
| CAS No. | 3211-76-5 | Test Date | 2026-07-15 |
| MFG Date | 2026-07-10 | Expiry Date | 2028-07-09 |
| Items | Specification | Methods | Results |
| Assay (SeMet) | ≥ 0.5% | HPLC | 0.52% |
| Total Selenium | ≥ 0.20% | ICP-MS / AAS | 0.21% |
| Appearance | White to Off-White Fine Powder | Visual | Conforms |
| Loss on Drying | ≤ 5.0% | Gravimetric | 2.8% |
| Heavy Metals | ≤ 10 ppm | ICP-MS | Conforms |
| Lead (Pb) | ≤ 5.0 mg/kg | ICP-MS | Conforms |
| Arsenic (As) | ≤ 2.0 mg/kg | ICP-MS | Conforms |
| Total Plate Count | ≤ 1000 cfu/g | Plate Count | Conforms |
| Yeast & Mold | ≤ 100 cfu/g | Plate Count | Conforms |
| E. coli | Negative / 25g | USP <62> | Conforms |
| Salmonella | Negative / 25g | USP <62> | Conforms |
| Shelf Life | 24 months from production date. Refer to the batch-specific COA for exact expiry. | ||
| Storage | Store in a cool, dry, dark, sealed container below 25 Deg C. Keep away from light and moisture. | ||
Selenium is delivered as an amino acid-bound organic molecule — the identical form the element takes inside whole foods. For formulators, this means a raw material that matches how the body already handles selenium from the diet, rather than an inorganic salt the body must process differently.
Selenium is the structural core of glutathione peroxidase, the enzyme family that neutralizes peroxides and shields cell membranes from oxidative damage. Supplementing selenium supports this endogenous defense system — the body’s own daily maintenance crew.
Selenium plays a documented role in the normal functioning of the immune system and the thyroid gland. As a key mineral in the daily nutrient picture, it supports the physiological processes consumers increasingly look for in their supplements.
With selenium standardized at 2,000 ppm on a uniform DCP carrier, every gram delivers the same measurable selenium dose. Formulators gain predictable label-claim support, and premix manufacturers gain a blend they can repeat with confidence.
Multi-mineral and multi-vitamin/mineral tablets, capsules, and powders with label-declared selenium — the organic amino acid form preferred where bioavailability and clean-label sourcing matter.
Livestock, poultry, and aquaculture feed premixes where organic selenium is specified — providing the trace mineral in the form animals absorb most efficiently.
Formulated nutritional products, powdered beverages, and fortified foods developed under applicable selenium fortification regulations — with a predictable, documentable selenium contribution per serving.
Integrated multi-nutrient premises where selenium must be combined with vitamins, minerals, and botanicals — the DCP carrier blends cleanly without interfering with co-formulated actives.
For brands positioning around organic, amino-acid-bound minerals — a single defined species with full analytical documentation, standing in contrast to undefined yeast-based selenium products.