Milk Thistle: Natural Liver Protection and Metabolic Support

Milk thistle (Silybum marianum) is a plant with a long history of medicinal use, particularly for protecting the liver and supporting the body’s metabolic functions. Its main active compound is silymarin, a mixture of flavonolignans that has beneficial effects on liver health, blood sugar regulation, and cardiovascular function. In addition, it possesses anti-inflammatory, antioxidant, and antifibrotic properties, making it an important therapeutic agent in the treatment of various liver diseases.

Biochemical Composition and Mechanism of Action

Milk thistle mainly contains silymarin, which is composed of flavonolignans (silybin, silydianin, and silychristin) as well as other bioactive substances such as taxifolin, quercetin, kaempferol, and apigenin (Raclariu-Manolică and Socaciu, 2023). These substances have strong antioxidant effects and protect liver cells from oxidative stress and toxins (Dhande et al., 2024). Silymarin supports the regeneration of hepatocytes, inhibits inflammatory processes, and increases the liver’s detoxification capacity by inhibiting lipid peroxidation (Surai et al., 2024). It also has antifibrotic effects, as it reduces collagen production in the liver and slows the progression of liver fibrosis (Jaffar et al., 2024). Research findings also indicate possible neuroprotective effects based on reducing neuroinflammation and supporting the survival of nerve cells under oxidative stress (Yardım et al., 2021). Silymarin activates enzymes involved in the detoxification of xenobiotics, thereby supporting the elimination of heavy metals and other toxic substances (Bjørklund et al., 2024). In toxic hepatitis caused by the death cap mushroom (Amanita phalloides), silymarin prevents toxins from entering hepatocytes and accelerates their regeneration (Tuğcan and Akpınar, 2025). In addition, its potential use in the treatment of liver complications associated with the use of certain medications is being investigated, for example during long-term use of paracetamol or chemotherapeutic agents (Okiljević et al., 2024; Wang et al., 2023).

Effects on Glucose Metabolism and the Cardiovascular System

Silymarin improves cellular insulin sensitivity and contributes to the regulation of blood glucose levels. Studies have demonstrated its positive effect on glycemic parameters in patients with type 2 diabetes (Ferdowsi et al., 2024). In addition, it supports cardiovascular health by lowering LDL cholesterol levels and protecting the vascular endothelium. Its mechanism of action is based on reducing oxidative stress and improving mitochondrial function in cardiac tissue (Ferdowsi et al., 2024; Zalat et al., 2021). Some studies suggest that silymarin may have a protective effect on cardiac tissue during ischemia and reperfusion injury. It also modulates the expression of genes associated with lipid metabolism and may therefore contribute to reducing the risk of atherosclerosis (Kadoglou et al., 2022; Zalat et al., 2021).

Dosage and Interactions with Other Substances

The recommended daily dose of milk thistle depends on the dosage form of the preparation. The usual dosage of silymarin is 100–360 mg of silibinin per single dose, with a maximum daily dose of 420–600 mg (Foghis et al., 2023). Pharmacokinetic studies show that after oral administration, only 20–50% of silymarin is absorbed, while up to 80% of the dose is excreted through the bile (Abenavoli and Milic, 2017; Javed et al., 2022). Modified nanoformulations, such as phosphatidylcholine or liposomal complexes, increase its bioavailability (Kesharwani et al., 2020). Milk thistle may be combined with other hepatoprotective substances such as curcumin or N-acetylcysteine for a synergistic effect (Chaachouay, 2025). Although silymarin is generally considered safe, it may interact with certain medications such as warfarin, statins, and some cytostatic drugs because it affects the activity of cytochrome P450 enzymes (Likhodii et al., 2024). The most common side effects are mild gastrointestinal complaints such as bloating or diarrhea (Akhtar et al., 2023).

Possible Alternatives and Related Supplements

Several other plant extracts have effects similar to those of milk thistle, for example Chinese magnolia vine (Schisandra chinensis) or artichoke extract (Cynara scolymus), which support detoxification and liver health (Pereira, 2016). Chinese magnolia vine contains lignans with protective effects on liver cells (Skalski et al., 2025), while artichoke stimulates bile production and supports digestive processes (Moradi et al., 2021). The combination of silymarin with resveratrol is also of interest, as resveratrol enhances its antioxidant and anti-inflammatory effects (Farzanegan et al., 2019). Synergistic combinations of these substances may improve the effectiveness of treatment for liver diseases and metabolic disorders (Pereira, 2016).

Future Prospects for the Use of Milk Thistle

In recent years, the use of silymarin in the treatment of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease has been investigated because of its ability to inhibit neuroinflammation and oxidative stress in brain tissue (Ashique et al., 2024). Its potential in oncology is also being studied, as it shows antiproliferative effects in certain types of cancer cells. Experimental studies indicate that silymarin may influence tumor-cell apoptosis by modulating signaling pathways associated with cell survival (Emadi et al., 2022; Wang et al., 2023). Another area of research is the use of silymarin nanoformulations to improve its bioavailability and therapeutic effectiveness (Kesharwani et al., 2020). Research is also focusing on its immunomodulatory effects and its potential in the treatment of autoimmune diseases (Esmaeil et al., 2017; Surai et al., 2024).

Conclusion

Milk thistle is a powerful natural antioxidant with a broad range of effects on human health. It protects the liver, supports the regulation of blood glucose levels, promotes cardiovascular health, and also has potential in the treatment of neurodegenerative and oncological diseases. Further clinical studies are required to better understand its effects and optimize dosage for different health-related applications.

Written for Kratom World by:
Ing. Matěj Malík, Ph.D.
Research Fellow, Postdoctoral Researcher
Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague (CZU)
Department of Agroenvironmental Chemistry and Plant Nutrition

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