Benefits
Liver enzymes and liver health
In a 12-month placebo-controlled trial of 179 adults with fatty liver disease, the silybin phytosome combined with vitamin E was followed by better liver enzymes, insulin resistance and liver tissue scores in the treated group but not the placebo group. Because vitamin E was included, the effect of Siliphos alone cannot be separated out.
Short-term liver enzyme changes
In a 7-day trial, 20 adults with chronic active hepatitis took the silybin phytosome (240 mg of silybin twice a day) or placebo. AST, ALT, GGT and bilirubin fell from starting levels in the treated group, while a marker of oxidative damage did not change; the abstract gives no direct comparison with placebo. It was too short and small to show lasting benefit.
Higher silybin absorption than standard silymarin
In 9 healthy volunteers, single doses of the complex gave higher blood silybin levels at every sampling time than silymarin with the same silybin content. In 9 surgical patients, about 11% of the silybin dose was recovered in bile versus 3% after silymarin. Better absorption does not by itself prove a greater health effect.
Mechanism of action
Silybin, the main milk thistle compound
Silymarin is a mix of flavonolignans from milk thistle, and silybin is its main active component. Siliphos supplies silybin rather than the full mix.
Phospholipid complex and absorption
Binding silybin to phosphatidylcholine appears to help it pass through the gut wall. In human studies, most absorbed silybin circulated in a conjugated form and much of the dose was probably excreted in bile, which delivers it to the liver.
Inflammation markers
In a 3-month study without a placebo group, people with fatty liver taking silybin, phospholipids and vitamin E had lower TNF-alpha, IL-6 and interferon-gamma. Without a placebo comparison, this cannot show the product caused the change.
Clinical trials
Multicenter, double-blind, placebo-controlled phase III trial of silybin phytosome coformulated with vitamin E (Realsil), taken twice daily for 12 months (Loguercio et al. 2012, Free Radical Biology and Medicine).
179 adults with biopsy-confirmed nonalcoholic fatty liver disease, 36 of them also with hepatitis C; 138 analyzed per protocol.
Liver enzymes, insulin resistance (HOMA) and liver tissue scores improved in the treated group but not in the placebo group; the abstract reports these as within-group changes. Side effects were short-lived (diarrhea, taste changes, itching) and none were serious. Vitamin E was part of the product.
Single-dose comparison of IdB 1016 and silymarin (360 mg silybin each), then 120 mg silybin twice a day for 8 days (Barzaghi et al. 1990, European Journal of Drug Metabolism and Pharmacokinetics).
Two groups of 9 healthy volunteers.
Blood silybin was higher at every sampling time after the complex than after silymarin. Half-life was short (generally under 4 hours), most circulating silybin was conjugated, and less than 3% of the dose appeared in urine.
Randomized, placebo-controlled pilot trial of IdB 1016, 240 mg silybin twice a day for 7 days (Buzzelli et al. 1993, International Journal of Clinical Pharmacology, Therapy, and Toxicology).
20 adults with chronic active hepatitis, 10 per group.
AST, ALT, GGT and total bilirubin fell in the treated group; malondialdehyde, copper and zinc did not change. The trial was very short and small.
Systematic review and meta-analysis of randomized trials of milk thistle versus placebo or no treatment (Rambaldi et al. 2007, Cochrane Database of Systematic Reviews).
1,088 patients with alcohol-related or hepatitis B or C liver disease in 18 trials.
Milk thistle had no significant effect on overall mortality, liver complications or liver histology. Liver-related deaths were lower across all trials but not in high-quality trials. Adverse events were not increased. Trial quality was low.