Siliphos® - Clinical Research Data Summary
Siliphos® Silybin Phytosome (Milk Thistle)
Siliphos® is a clinically studied ingredient used in the following Silver Fern™ Brand product:
- Liver Complex – https://www.silverfernbrand.com/products/liver-complex
Introduction
Siliphos® is a patented silybin phytosome derived from milk thistle (Silybum marianum), designed to enhance the absorption of silybin — the plant's primary bioactive compound associated with liver support. Unlike standard milk thistle extracts, which have limited bioavailability, Siliphos® binds silybin to phospholipids using Indena's Phytosome® technology to help improve absorption compared to conventional extracts. Supported by human clinical research, Siliphos® helps support healthy liver function, contributes to antioxidant defenses, and helps maintain normal liver and metabolic health markers, making it a widely used ingredient in advanced liver support formulations.*
These are the studies for Siliphos®. Below, we provided a summary of each key data for each study, along with a link to the complete clinical research.
- Summary of Study 1 – Full Study: https://pubmed.ncbi.nlm.nih.gov/1499596/
- Summary of Study 2 – Full Study: https://pubmed.ncbi.nlm.nih.gov/8149949/
- Summary of Study 3 – Full Study: https://pubmed.ncbi.nlm.nih.gov/1329780/
- Summary of Study 4 – Full Study: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
- Summary of Study 5 – Full Study: https://pubmed.ncbi.nlm.nih.gov/17410454/
- Summary of Study 6 – Full Study: https://pubmed.ncbi.nlm.nih.gov/16698763/
- Summary of Study 7 – Full Study: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
- Summary of Study 8 – Full Study: https://www.researchgate.net/publication/7599396
- Summary of Study 9 – Full Study: https://pubmed.ncbi.nlm.nih.gov/16164374/
- Summary of Study 10 – Full Study: https://pubmed.ncbi.nlm.nih.gov/1940257/
- Summary of Study 11 – Full Study: https://pubmed.ncbi.nlm.nih.gov/18814247/
- Summary of Study 12 – Full Study: https://pubmed.ncbi.nlm.nih.gov/22343419/
Ingredient Manufacturer Link: https://www.indena.com/us/product/siliphos/
Study 1 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/1499596/
Comparative Bioavailability of Silipide®, a Silybin–Phosphatidylcholine Complex, in Rats
Morazzoni P. et al. European Journal of Drug Metabolism and Pharmacokinetics. 1992; 17(1): 39–44.
This preclinical pharmacokinetic study evaluated whether complexing silybin with phosphatidylcholine (phytosome technology) improves oral absorption and systemic availability compared with uncomplexed silybin in a rat oral absorption model (200 mg/kg).
Key Findings (What the Study Showed)
- Silipide®: Peak plasma concentration ~8.17 µg/mL; total plasma exposure (AUC₀–₆h) ~74.23 µg·h/mL
- Standard silybin: Peak concentration below detection limits; AUC negligible
- Biliary excretion: Silipide® ~3.73% of dose vs. standard silybin ~0.001%
- Urinary recovery: Silipide® ~3.26% vs. standard silybin ~0.03%
- Phospholipid complexation produced substantially higher measurable plasma and biliary levels in this animal model
Why This Study Matters
This research helped establish the rationale for phytosome-based delivery systems for polyphenols such as silybin. By binding the compound to phospholipids, the formulation may substantially improve absorption and systemic availability compared with traditional milk thistle extracts.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/1499596/
Study 2 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/8149949/
Comparative Bioavailability of Silipide® vs Standard Silymarin
Morazzoni P. et al. European Journal of Drug Metabolism and Pharmacokinetics. 1993; 18:289–297.
This preclinical pharmacokinetic study in rats compared the pharmacokinetic profile of phosphatidylcholine-complexed silybin (Silipide®) vs. traditional silymarin extract.
Key Findings (What the Study Showed)
- Silipide®: Unconjugated silybin ~9.0 ± 3.0 µg/mL; total silybin ~93.4 ± 16.7 µg/mL in plasma
- Silymarin: Plasma concentrations several-fold lower, often near detection limits
- Biliary recovery (24h): Silipide® ~13% vs. silymarin ~2%
- Relative bioavailability: Silipide® demonstrated approximately 10-fold higher relative bioavailability compared with silymarin based on cumulative biliary excretion
Why This Study Matters
This study demonstrates that formulation plays an important role in the absorption of milk thistle flavonolignans, with the phosphatidylcholine complex producing dramatically higher plasma and biliary levels compared with standard silymarin.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/8149949/
Study 3 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/1329780/
Comparative Pharmacokinetics of Silipide® vs Standard Silymarin in Humans
Schandalik R. et al. Arzneimittel-Forschung / Drug Research. 1992; 42(II): 964–968.
This controlled pharmacokinetic study was conducted in patients with prior cholecystectomy — allowing direct measurement of silybin levels in bile after ingestion — comparing phosphatidylcholine-complexed silybin (Silipide®) vs. standard silymarin extract at equivalent silybin doses.
Key Findings (What the Study Showed)
- Silipide® produced higher and earlier peak levels of silybin in bile compared with standard silymarin
- Standard silymarin produced substantially lower biliary concentrations, with levels approaching detection limits in some cases
- Greater cumulative biliary recovery with Silipide® vs. standard silymarin throughout the sampling period
- These human pharmacokinetic data support improved absorption with phytosome technology
Why This Study Matters
This is the first human pharmacokinetic study in this body of evidence, directly measuring silybin in bile after oral administration. The higher and earlier biliary levels with Silipide® vs. silymarin provide direct human evidence supporting the absorption advantage of phytosome technology.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/1329780/
Study 4 Summary
Complete Study Information: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
Review of Pharmacokinetics and Biological Properties of Silybin
Vailati A. et al. Fitoterapia 64:219-228 (1993).
This review evaluated available research on the pharmacology, pharmacokinetics, and biological properties of silybin, the primary flavonolignan found in milk thistle.
Key Findings (What the Review Showed)
- Silybin is the most abundant and biologically active compound in silymarin; traditional extracts show relatively limited absorption
- Phospholipid-based formulations have demonstrated improved systemic exposure compared with standard extracts
- Experimental research suggests silybin may support antioxidant activity, influence inflammatory signaling pathways, and interact with cellular membranes
- Most mechanistic evidence originates from in vitro and animal models
- Milk thistle extracts and silybin preparations were generally well tolerated at typical intake levels
Why This Study Matters
This review highlights multiple biological mechanisms associated with silybin and emphasizes the importance of formulation strategies that improve absorption — providing scientific context for why Siliphos® was developed using phytosome technology.*
Reference Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
Study 5 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/17410454/
Effect of a Silybin-Vitamin E-Phospholipid Complex on Liver-Related Markers
Loguercio C. et al. Digestive Diseases and Sciences. 2007; 52(9):2387-2395.
This open-label pilot clinical study evaluated a silybin-vitamin E-phospholipid complex in 85 adults with liver steatosis over 6 months, assessing liver enzyme levels, ultrasound-assessed liver steatosis, and metabolic parameters including insulin levels.
Key Findings (What the Study Showed)
- Participants showed reductions in certain liver enzyme levels during the study period
- Ultrasound evaluations indicated changes in liver steatosis scores over the course of the study
- Changes were also observed in insulin-related markers and inflammatory signaling molecules
- The intervention was well tolerated with no major safety concerns reported
Why This Study Matters
This open-label pilot study provides early human clinical evidence that bioavailable silybin formulations may influence liver-related laboratory markers and metabolic measurements over a 6-month period.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/17410454/
Study 6 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/16698763/
Preliminary Clinical Observations on a Silybin–Vitamin E–Phospholipid Complex
Federico A., Tuccillo C., Loguercio C., et al. Gut. 2006; 55(6):901–902.
This preliminary open-label clinical report described early observations evaluating a formulation containing silybin, vitamin E, and phospholipids in individuals with liver steatosis over several months of supplementation.
Key Findings (What the Study Showed)
- Changes reported in markers associated with insulin metabolism during the observation period
- Reductions in certain liver enzyme levels were reported during the study period
- Ultrasound assessments indicated changes in liver steatosis scores in some participants
- The formulation was well tolerated with no major adverse events reported
- The authors noted that larger and more controlled clinical trials would be needed to further evaluate these findings
Why This Study Matters
This preliminary report provides early human clinical observations supporting silybin-phospholipid complex research in liver-related settings, and informed the design of the larger controlled trials that followed.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/16698763/
Study 7 Summary
Complete Study Information: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
Silybin and the Liver: From Basic Research to Clinical Research
Loguercio C., Festi D. World Journal of Gastroenterology. 2011. PMCID: PMC3098397.
This translational review examines the biological properties of silybin and summarizes research spanning cellular studies, animal models, and human clinical investigations, including pharmacokinetics and clinical observations related to silybin and related milk thistle preparations.
Key Findings (What the Review Showed)
- Silybin is the most abundant and biologically active compound in silymarin; native silybin has relatively poor oral absorption
- Experimental research suggests silybin may support antioxidant activity (ROS scavenging, glutathione support), influence inflammatory signaling pathways (NF-κB, cytokine signaling), and interact with cellular membrane structures
- Phospholipid-complexed silybin formulations may improve absorption and systemic exposure compared with conventional extracts
- Human studies have reported changes in liver-related laboratory markers; clinical findings vary depending on formulation, dose, and study design
- Milk thistle preparations generally well tolerated with few reported adverse effects
Why This Study Matters
This review underscores the importance of formulation when delivering milk thistle compounds, and provides comprehensive scientific context for the biological mechanisms that may explain the clinical findings observed with Siliphos®.*
Reference Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC3098397/
Study 8 Summary
Complete Study Information: https://www.researchgate.net/publication/7599396
Review of the Bioavailability and Clinical Efficacy of Milk Thistle Phytosome: A Silybin-Phosphatidylcholine Complex (Siliphos®)
This review evaluates whether complexing silybin with phosphatidylcholine improves oral absorption, systemic availability, and delivery compared with traditional milk thistle extracts, analyzing pharmacokinetic studies, mechanistic research, and human clinical investigations.
Key Findings (What the Review Showed)
- Silybin has relatively low solubility and limited absorption in traditional extract form, contributing to variable systemic exposure
- Siliphos® phytosome technology may improve integration into intestinal membranes, increase measurable plasma concentrations, and enhance consistency of absorption
- Across multiple pharmacokinetic studies, phospholipid-complexed silybin demonstrated higher systemic exposure, higher biliary concentrations, and more consistent absorption vs. standard extracts
- Some studies reported several-fold higher systemic exposure compared with traditional silymarin preparations
- Human studies reported changes in liver-related laboratory markers, metabolic measurements, and oxidative stress markers
- Silybin-phospholipid complexes demonstrated a favorable tolerability profile
Why This Study Matters
This review concludes that phospholipid-complexed silybin formulations may improve the absorption and systemic availability of silybin compared with traditional milk thistle extracts, directly supporting the scientific rationale for Siliphos®.*
Reference Link: https://www.researchgate.net/publication/7599396
Study 9 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/16164374/
Review of the Bioavailability of a Silybin–Phosphatidylcholine Complex (Siliphos®)
Published review evaluating Siliphos® pharmacokinetics and clinical evidence.
This review evaluates whether Siliphos® improves absorption and systemic availability of silybin compared with conventional milk thistle extracts, examining pharmacokinetic studies, mechanistic research, and clinical investigations.
Key Findings (What the Review Showed)
- Conventional silymarin preparations show low oral absorption, high variability between individuals, and limited systemic exposure
- Siliphos® phytosome technology may improve interaction with intestinal membranes, increase plasma concentrations, and enhance consistency of absorption
- Multiple pharmacokinetic studies showed higher systemic exposure, higher biliary concentrations, and more consistent individual absorption with Siliphos®
- Some studies reported several-fold increases in systemic exposure compared with standard silymarin
- Human studies observed changes in liver-related markers, oxidative stress measurements, and metabolic parameters
- Silybin-phospholipid complexes demonstrated favorable tolerability
Why This Study Matters
This review highlights that pharmacokinetic limitations of conventional milk thistle may contribute to inconsistent findings in early research, and that phytosome technology addresses these limitations through improved and more consistent absorption.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/16164374/
Study 10 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/1940257/
Effect of Silibinin on Biliary Lipid Composition
Clinical and experimental investigation.
This investigation — combining experimental animal models and human clinical observations — evaluated whether silibinin (silybin) influences the composition of bile lipids, examining cholesterol, bile acid, phospholipid content, and the cholesterol saturation index (CSI).
Key Findings (What the Study Showed)
- Researchers observed changes in the balance of bile components during silibinin administration
- These changes included lower cholesterol concentration in bile and higher bile acid and phospholipid levels
- A reduced cholesterol saturation index (CSI) was observed
- The authors suggested these effects may relate to silibinin's influence on hepatic lipid metabolism and oxidative stress pathways
- Silibinin was well tolerated in both experimental models and human observations
Why This Study Matters
This study provides evidence of silybin's influence on hepatobiliary physiology beyond antioxidant activity, showing measurable changes in bile lipid composition that may be relevant to normal liver and gallbladder function.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/1940257/
Study 11 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/18814247/
Silybin–Vitamin E–Phospholipid Complex and Liver-Related Markers in Adults with Hepatitis C Infection
Open-label clinical study.
This open-label clinical study examined the effects of a silybin-vitamin E-phospholipid complex in adults with chronic hepatitis C infection, including those who had not responded fully to conventional antiviral therapy, over several months of supplementation.
Key Findings (What the Study Showed)
- Participants showed reductions in certain liver enzyme levels (ALT, AST, γ-GT) during the supplementation period
- Researchers observed changes in biochemical markers associated with oxidative stress
- Changes were reported in markers associated with insulin metabolism
- The study reported changes in indices related to liver steatosis and fibrosis-associated biomarkers
- Well tolerated with no major adverse events observed
Why This Study Matters
This study extends the clinical evidence for silybin phytosome formulations to a different liver health research population, with observed changes in liver enzymes, oxidative stress markers, and metabolic parameters over the supplementation period.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/18814247/
Study 12 Summary
Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/22343419/
Randomized Controlled Trial of a Silybin–Phosphatidylcholine–Vitamin E Complex
Randomized, controlled clinical trial.
This randomized, controlled clinical trial evaluated a silybin + phosphatidylcholine + vitamin E complex vs. placebo in adults with liver steatosis over approximately 12 months, assessing liver enzyme levels, insulin-related metabolic markers (HOMA-IR), oxidative stress markers, ultrasound assessment, and fibrosis-associated biomarkers.
Study Design Highlights
- Study design: Randomized, controlled clinical trial
- Intervention: Silybin + phosphatidylcholine + vitamin E complex vs. placebo
- Duration: Approximately 12 months
Key Findings (What the Study Showed)
- Participants receiving the silybin complex showed changes in liver enzyme levels compared with placebo
- Changes were observed in insulin-related metabolic measurements (HOMA-IR) during the study
- Biochemical markers associated with oxidative stress changed during the intervention
- Ultrasound assessments and fibrosis-related biomarkers showed measurable changes in the intervention group vs. baseline
- Well tolerated with no major adverse events reported
Benefits of Siliphos® Demonstrated by This Study
Based directly on the randomized controlled trial outcomes, the silybin-phosphatidylcholine complex was shown to:
✓ Support changes in liver enzyme levels vs. placebo over 12 months
✓ Support changes in insulin-related metabolic markers
✓ Support changes in oxidative stress biomarkers
✓ Show changes in ultrasound-based and fibrosis-associated measures
✓ Demonstrate a well-tolerated profile over 12 months
Why This Study Matters
As the most rigorous study in this body of evidence — a 12-month randomized controlled trial with a placebo group — this study provides the strongest clinical support for silybin-phosphatidylcholine formulations influencing liver-related laboratory markers, oxidative stress measurements, and metabolic parameters.*
Reference Link: https://pubmed.ncbi.nlm.nih.gov/22343419/
Big-Picture Integration with Other Studies
- Studies 1–3: Pharmacokinetic studies (2 preclinical, 1 human) demonstrate that phytosome technology improves silybin bioavailability — showing ~10-fold higher relative biliary bioavailability vs. silymarin in animal models and higher, earlier biliary silybin levels in humans vs. standard silymarin.
- Studies 4, 7: Scientific reviews summarizing silybin's biological mechanisms including antioxidant activity (ROS scavenging, glutathione), NF-κB and cytokine pathway interactions, and cellular membrane effects.
- Studies 8, 9: Dedicated Siliphos® bioavailability reviews concluding that phytosome technology meaningfully improves absorption consistency and systemic exposure compared with conventional milk thistle.
- Studies 5, 6, 11: Open-label and preliminary human clinical studies reporting changes in liver enzyme levels, oxidative stress markers, and metabolic parameters with silybin-vitamin E-phospholipid formulations.
- Study 10: Investigation demonstrating silybin's influence on biliary lipid composition including reduced cholesterol saturation index.
- Study 12: 12-month randomized controlled trial — the strongest clinical evidence — showing changes in liver enzymes, HOMA-IR, oxidative stress markers, and imaging measures compared with placebo.
Siliphos® Ingredient Summary & Real-World Relevance
Siliphos® is a bioavailable form of milk thistle designed to improve the absorption of silybin — the compound responsible for milk thistle's biological activity. By combining silybin with phosphatidylcholine using Indena's patented Phytosome® technology, Siliphos® helps overcome the absorption limitations associated with traditional milk thistle extracts. Pharmacokinetic studies demonstrate approximately 10-fold higher relative bioavailability in animal models and higher, earlier biliary silybin levels in humans compared with standard silymarin.*
Experimental research suggests silybin may support antioxidant activity, influence cellular responses to oxidative stress, and interact with inflammatory signaling pathways. Clinical research — including a 12-month randomized controlled trial — reports changes in liver-related laboratory markers, metabolic measurements, and oxidative stress biomarkers with silybin-phospholipid complex formulations. Siliphos® and related silybin preparations have demonstrated a well-tolerated profile across the research literature.*
Ingredient Manufacturer Link: https://www.indena.com/us/product/siliphos/
Siliphos® is a clinically studied ingredient used in the following Silver Fern™ Brand product:
*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.