Thistle and Reduced Gamma-Glutamyl Transferase Levels

Research synthesisLow evidenceMixed effect size3 studies · 2 beneficial · 1 neutral · 0 harmful

Across 3 studies, 2 reported beneficial effects (one large, one moderate) of thistle-derived compounds on reducing gamma-glutamyl transferase (GGT) levels, while 1 meta-analysis found a neutral effect with small magnitude. All 3 studies involved clinical or healthy adult populations, and effects were typically observed over a median duration of 104 days. The evidence suggests a predominantly beneficial direction, though effect sizes varied from small to large.

Studied populations: adults with metabolic dysfunction-associated steatotic liver disease (MASLD), adults with alcoholic liver disease (ALD), and healthy adults

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The neutral meta-analysis (low-certainty evidence) had the largest sample size (2,069 participants) and used silymarin complex, which may differ in efficacy from the silibinin form used in the beneficial studies. Differing forms and populations across studies limit direct comparison.

Generated Jul 3, 2026

Time to effect

Median: 3.5 months · IQR 9.4 weeks–4.7 months · Range 4 weeks–6 months — Reported in 2 of 3 studies

Safety in these studies

non-serious adverse eventsNo significant differenceRR 1.29, 95% CI 0.88 to 1.89; 4 trials, 282 participants
The evidence is very uncertain about the effect of silymarin monotherapy versus no intervention or placebo on non-serious adverse events (RR 1.29, 95% CI 0.88 to 1.89; 4 trials, 282 participants; very low-certainty evidence).
from: Silymarin for adults with metabolic dysfunction-associated steatotic liver disease.
serious adverse eventsNo significant differenceSerious adverse eventPeto OR 1.55, 95% CI 0.26 to 9.28; 4 trials, 304 participants
The evidence suggests that silymarin monotherapy versus no intervention or placebo may result in little to no difference in serious adverse events (Peto OR 1.55, 95% CI 0.26 to 9.28; 4 trials, 304 participants; low-certainty evidence).
from: Silymarin for adults with metabolic dysfunction-associated steatotic liver disease.
Overall tolerabilityReported
Although one trial reported the occurrence of serious adverse events, none were deemed to be related to the study drugs.
from: Silymarin for adults with metabolic dysfunction-associated steatotic liver disease.
gastrointestinal reactionsReported
Silibinin capsules exhibited a favorable safety profile, with only mild gastrointestinal reactions and reports of insomnia as adverse events.
from: Evidence construction of Silibinin capsules against alcoholic liver disease based on a met
insomniaReported
Silibinin capsules exhibited a favorable safety profile, with only mild gastrointestinal reactions and reports of insomnia as adverse events.
from: Evidence construction of Silibinin capsules against alcoholic liver disease based on a met

3 of 3 papersPopulation:

Silymarin for adults with metabolic dysfunction-associated steatotic liver disease.
- 2025-06-24
- Meta-Analysis · n = 2,069
- The Cochrane database of systematic reviews 2025(6)
- - Caie Wang
  - Yiyang Shang
  - Ghid Kanaan
  - Lu Chai
  - Hui Li
  - Xingshun Qi
- PubMed: 40552569
- DOI: 10.1002/14651858.cd015524.pub2
3 Insights on
- Reduced Gamma-Glutamyl Transferase Levels
- High evidence
- Clinical
Silymarin complex versus other interventions ... GGT (MD 11.60 U/L, 95% CI -12.11 to 35.31; 1 trial, 126 participants; low-certainty evidence)
Effect
Neutral
Effect size
Small
Significant
No
Evidence construction of Silibinin capsules against alcoholic liver disease based on a meta-analysis and systematic review.
- 2025-02-04
- Systematic Review · n = 221
- Frontiers in pharmacology 16
- - Yan Wang
  - Wenmin Yang
  - Yuan Yang
  - Xingning Liu
  - Lanfen Peng
  - Qi Huang
  - Kongli Fan
  - Rui Hu
  - Jinyu Yi
  - Xin Zhong
  - Jing Li
  - Jialing Sun
  - Xiaozhou Zhou
- PubMed: 39968181
- DOI: 10.3389/fphar.2025.1516204
9 Insights on
- Reduced Gamma-Glutamyl Transferase Levels
- High evidence
- Clinical
GGT [SMD = -1.48, 95% CI (-2.09, -0.87)]
Effect
Beneficial
Effect size
Large
Significant
Yes
Long-term safety and efficacy of a highly purified plant-based nutraceutical for improving clinical parameters of liver function in healthy participants: a randomized, double-blind, placebo-controlled clinical trial.
- 2026-01-23
- Clinical Trial · n = 130
- Frontiers in nutrition 12
- - Ghanashyam Patel
  - Saumin Shah
  - Christopher R D'Adamo
- PubMed: 41659807
- DOI: 10.3389/fnut.2025.1721748
4 Insights on
- Reduced Gamma-Glutamyl Transferase Levels
- High evidence
- Adults
Mean improvements in ALT, AST, ALP, and GGT were significantly greater with the nutraceutical product than placebo (p ≤ 0.001).
Effect
Beneficial
Effect size
Moderate
Significant
Yes

Thistle and Reduced Gamma-Glutamyl Transferase Levels

Silymarin for adults with metabolic dysfunction-associated steatotic liver disease.

Evidence construction of Silibinin capsules against alcoholic liver disease based on a meta-analysis and systematic review.

Long-term safety and efficacy of a highly purified plant-based nutraceutical for improving clinical parameters of liver function in healthy participants: a randomized, double-blind, placebo-controlled clinical trial.