Bulk Milk Thistle Extract Supplier — Silymarin, Silybin & Water-Soluble Silymarin, B2B Wholesale
Valeherb supplies milk thistle extract bulk wholesale — from Silybum marianum (L.) Gaertn. seed grown at our own cultivation base — across three product lines: Silymarin (the standardized flavonolignan complex), Silybin (the purified single-compound fraction), and Water-Soluble Silymarin (a meglumine-complexed grade addressing the compound class’s well-documented aqueous solubility limitation). Silymarin is extracted using acetone, ethanol, or ethyl acetate, with residual solvent levels verified per ICH Q3C on every batch.
On this page: available grades, from seed to extract, what silymarin and silybin actually are, the water-solubility challenge, research background, formulation applications, sourcing criteria, and regulatory guidance.
Available Grades
Silymarin
Light yellow to yellowish-brown solid powder, bitter taste. Available via three extraction media, each yielding the same assay range.
| Product | Total Silymarin (UV) | Flavonolignan Content (HPLC) |
|---|---|---|
| Silymarin Extracted by Acetone | UV 70% – 90% | HPLC 40% – 60% |
| Silymarin Extracted by Ethyl Acetate | UV 70% – 90% | HPLC 40% – 60% |
| Silymarin Extracted by Ethanol | UV 70% – 90% | HPLC 40% – 60% |
| Combined Grade | UV 80% | Silybin & Isosilybin 30% (HPLC) |
Silybin
CAS 22888-70-6. Off-white solid powder, bitter taste.
| Grade | Assay |
|---|---|
| Range | HPLC 70% – 98% |
Water-Soluble Silymarin
Yellow-brown solid powder, bitter taste, soluble in water.
| Grade | Assay |
|---|---|
| Range | UV 20% – 45% |
Both UV (total silymarin, 288 nm) and HPLC (individual flavonolignan quantification) testing available and reported separately per batch, in line with European Pharmacopoeia methodology. Custom standardization and extraction solvent selection available on request. MOQ, lead time, and current pricing available on inquiry.
From Seed to Extract: Sourcing and Traceability
Valeherb’s milk thistle seed is sourced from our own cultivation base. Seed is air-screened and cold-pressed; the resulting press cake is crushed and solvent-extracted (acetone, ethanol, or ethyl acetate) to yield crude silymarin paste, which undergoes hexane degreasing, refinement, drying, and milling to finished Silymarin powder. Silybin is produced from this Silymarin through a two-stage dissolution-crystallization-filtration cycle to reach single-compound purity. Pressed milk thistle seed oil and milk thistle honey — both produced at the same cultivation base — are available as complementary raw materials for buyers sourcing multiple milk thistle-derived ingredients from a single traceable supply chain.
Silymarin, Silybin, and Silibinin: What’s the Actual Relationship
These three names cause more sourcing confusion than almost any other botanical ingredient family. Silymarin is the standardized flavonolignan complex extracted from milk thistle seed — a mixture of silybin (silibinin) A and B, isosilybin (isosilibinin) A and B, silychristin, and silydianin, defined by the European Pharmacopoeia as the sum of these named compounds.[2] Silybin is the single most abundant and pharmacologically active flavonolignan within that complex, typically accounting for approximately 50–60% of total silymarin content, with silychristin contributing roughly 20%, silydianin roughly 10%, and isosilybin roughly 5% — the remainder comprising taxifolin, quercetin, and minor polyphenols.[6] Silibinin is not a different compound at all — it is a direct synonym for silybin, used interchangeably in much of the European and clinical pharmaceutical literature.[3] For the full naming breakdown — including why commercial listings sometimes treat these as three separate ingredients — see Silymarin vs Silybin vs Silibinin: Naming and Compound Differences.
A related but separate question is how silymarin relates to the whole milk thistle seed or crude extract — silymarin makes up only about 1.5–3% of the seed’s dry weight, meaning “milk thistle extract” and “silymarin” are not interchangeable specifications without a stated standardization level. For that distinction, see Milk Thistle Extract vs Silymarin: Is There a Difference?
The Water-Solubility Challenge
Silymarin and silybin are, in their native crystalline form, poorly soluble in water — soluble instead in acetone, ethanol, ethyl acetate, and methanol. This is the single most consistent finding across published pharmacokinetic research on the compound class: oral bioavailability is limited primarily by poor aqueous solubility and rapid first-pass conjugation, with silymarin’s biliary recovery reported as low as 2–3% after oral administration in some studies.[4] Valeherb’s Water-Soluble Silymarin grade addresses this directly at the raw-material level: Silymarin is complexed with meglumine (a pharmaceutical-grade solubilizing agent) in anhydrous ethanol to form a water-dispersible complex, then refined and dried to finished powder. Separately, published clinical research on a silybin-phosphatidylcholine complex (a different solubility-enhancement approach) found significantly higher plasma silybin levels compared with conventional silymarin tablets in a randomized crossover study in healthy volunteers.[5] For a full technical comparison of these solubility-enhancement approaches, see Silybin Phosphatidylcholine and Water-Soluble Silymarin: A Solubility Guide.
Research Background
Provided as scientific context for formulators, not as claims for any Valeherb product.
Compound Composition and Standardization
Bijak (2017) reviewed the chemistry, bioavailability, and metabolism of silybin, confirming its status as the major and most extensively studied flavonolignan in silymarin.[1] A 2024 HPLC compositional study analysing more than 40 commercial milk thistle extract products found that the ratio of silybin B to silybin A remained highly consistent across products and source seed samples, proposing this ratio as a quality-verification tool for standardized extracts.[2]
Pharmacology and Mechanism
Gillessen and Schmidt (2020) reviewed silymarin’s pharmacological profile, characterising documented actions including antioxidant, anti-inflammatory, antifibrotic, and insulin-resistance-modulating activity. The same review noted a favourable cytochrome P450 interaction profile at supratherapeutic concentrations: negligible inhibition of CYP1A2, 2A6, 2B6, 2C8, 2C9, and 2E1, minor (<20%) inhibition of CYP3A4, and moderate (<40%) inhibition of CYP2C19 and CYP2D6.[6] A separate 3-year non-human primate study fed alcohol (50% of daily calories) with or without concomitant silymarin found that silymarin significantly reduced the alcohol-induced increase in hepatic collagen type I observed in liver biopsy samples, alongside reduced markers of oxidative stress.[7] These are preclinical and mechanistic findings described here as research context, not claims for any Valeherb product.
Bioavailability Research
Published pharmacokinetic reviews have consistently documented silymarin’s poor oral bioavailability, driven by low aqueous solubility and rapid hepatic conjugation.[4] Méndez-Sánchez et al. (2019) conducted a randomized, blinded, crossover study in 23 healthy volunteers comparing a silybin-phosphatidylcholine complex against conventional silymarin tablets, finding statistically significant improvements in silybin plasma pharmacokinetic parameters with the complexed formulation.[5]
Formulation Applications
- Standardized liver-support supplement capsules and tablets: Silymarin UV80% / HPLC45-60% grade at typical inclusion levels matching EP-monograph standardization; the most common commercial specification globally
- Premium high-potency capsules: Silybin 70-98% HPLC for concentrated single-compound positioning
- Water-phase and beverage applications: Water-Soluble Silymarin (UV 20-45%) for functional beverages, drink powders, and aqueous formulation systems where standard silymarin’s insolubility is a barrier
- Bioavailability-enhanced delivery systems: Silybin complexed with phosphatidylcholine (phytosome technology) for soft-gel capsule formats targeting improved plasma exposure, based on published clinical pharmacokinetic research
- Veterinary liver-support formulations: Silybin-phosphatidylcholine complex is also documented in published veterinary pharmacokinetic research (canine models), relevant to formulators supplying the pet-supplement channel
Sourcing Criteria
| Criterion | What to Require |
|---|---|
| Species & Plant Part | Silybum marianum (L.) Gaertn. seed confirmed on COA — the sole commercial source of silymarin/silybin |
| Dual Assay Method | Both UV (total silymarin at 288 nm) and HPLC (individual flavonolignan breakdown — silybin A, silybin B, isosilybin A, isosilybin B, silychristin, silydianin) reported per batch, per EP monograph convention |
| Extraction Solvent | Confirm acetone, ethanol, or ethyl acetate as processing solvent; residual solvent limits verified per ICH Q3C on every batch |
| Grade Match to Application | Confirm whether your formulation requires the full Silymarin complex, purified Silybin, or the Water-Soluble (meglumine-complexed) Silymarin grade — these are not interchangeable at equivalent label weight |
| Third-Party COA | Silymarin/silybin content (UV + HPLC), heavy metals (USP <232>), residual solvents (ICH Q3C), pesticide residues, microbial limits, aflatoxins, moisture — per production batch from accredited laboratory |
Regulatory Guidance
- US (DSHEA): Liver-support and antioxidant structure/function claims are supportable with published research — self-substantiation and FDA disclaimer required. Disease treatment claims require drug-level approval and are not supported by current supplement positioning. FDA-registered facility (21 CFR Part 111)
- EU: Standardized silymarin extract has European Pharmacopoeia monograph status (dry extract, 30.0–65.0% silymarin by the defined flavonolignan sum). Confirm current food supplement vs. medicinal product classification for your specific target EU market and claim set
- China (ChP): Milk thistle (水飞蓟) is a listed medicinal/food-use botanical under Chinese regulatory frameworks; ChP compliance documentation available for domestic China market and export
- General: Given silymarin’s documented CYP450 interaction profile, Valeherb recommends finished-product formulators include appropriate drug-interaction disclosure and confirm current regulatory guidance for their specific target market before finalizing product positioning
