There are many uses of milk thistle, as well as factors that can determine how long someone will need to take it to do their job.
Milk thistle can improve the way the hepatic system works when injured. There are conflicting reviews of the literature on efficacy and treatment duration due to study design. There are many small clinical trials that show the effectiveness of milk thistle on the support of liver related diseases, including those involving blood sugar problems or cancer.
Milk thistle has also been used for other things.
- The treatment of high cholesterol levels.
- There are problems with the bladder.
- There are two types of cancer in breast and prostrate.
- and as an immune modulator (1).
What Are the Functions of Milk Thistle?
Milk thistle (silymarin) affects health primarily through its antioxidant abilities. Silymarin (milk thistle) acts as a free radical scavenger and modulates the enzymes that cause liver cellular damage, fibrosis and cirrhosis. By decreasing cellular oxidative stress and cytotoxicity, silymarin protects those liver cells that have not been damaged irreversibly (2).
What Conditions Are Treated by Milk Thistle?
Approximately 2 million people die of liver disease every year, with few treatments other than lifestyle. Milk thistle has received a lot of attention in the past 20 years due to its excellent safety profile and the fact that it can be used for a wide range of diseases, including liver disease.
Milk thistle can be used for a number of purposes, including the treatment of toxins in the body, the prevention of cirrhosis, and the suppression offibrogenic effects of alcohol.
Milk thistle is most often used in liver cirrhosis/alcohol – related liver disease, nonalcoholic fatty liver disease, non-alcoholic steatohepatitis (NASH), the ingestion of toxic amatoxin mushrooms, radiation mucositis and liver damage from the ingestion of toxic chemicals (2, 3).
Factors that Affect Duration of Treatment
Bioavailability of the formulation used is paramount both in study results and clinical endpoints obtained for the dosage given. Reviews of studies may show little effect from small doses but statistical effects from large doses and the form of milk thistle may have made a difference in the amount needed to make a statistical change (1, 4).
When silymarin is complexed with phosphatidylcholine and/or -cyclodextrin, it has been shown that it can have a therapeutic effect at lower doses and/or shorter.
The state of liver damage and effectiveness is also correlated. The timing of delivery of milk thistle is imperative with earlier interventions faring better (4).
Standardizing the milk thistle extract to silybin makes a positive difference in treatment duration.
Dosage and Duration of Milk Thistle Therapy
Studies have shown that the usual dose of milk thistle or silybin can be taken in three different amounts. The short half-life of the herb causes the doses to be divided.
A review of the literature shows a response to silybin + phospholipids in nonalcoholic fatty liver disease (NAFLD) patients in 6 months with improvements in insulin resistance, liver enzymes and the degree of steatosis noted as well (4).
Liver Cirrhosis/Alcohol-Related Liver Disease
In one study the four-year survival rate was significantly higher (58% vs. 39%) in silymarin recipients as opposed to the placebo group with a treatment period of at least 24 months and an observation period of 4 years. A review of clinical data across five studies showed a pooled liver-related mortality rate of 4.9% in the silymarin group compared with 9.3% in the placebo group (2).
Studies suggest that silymarin should be approved for liver support, not for treatment of viral hepatitis. Baseline use was associated with significantly less histological damage in patients with chronic hepatitis C in a cohort of 177 Egyptian patients over a 12-month period of time and an increase in quality of life scores (2).
Other studies show a preliminary decrease in liver enzymes in alcoholic liver disease at four weeks with the significance of the decrease in liver enzymes unknown (2). In other words, the blood samples were not correlated with histological data or other liver function tests.
Oxidative Stress Patterns
Improvement in oxidative stress parameters was consistently noted at six months’ duration of treatment with a specialized milk thistle delivery system (2). Improvement in oxidative stress patterns is responsible for improved insulin-signaling and liver cell functioning.
Blood Glucose and Insulin Levels
Some studies show no improvement in fasting blood glucose levels at three months but show improved values in HBA1C only. And in another study at six months, adequate insulin production was enabled to lower fasting blood glucose levels by 10% when compared with placebo in Type 1 diabetics (3). These results not only highlight the inconsistency but point towards a potential deeper clinical response with a longer duration of treatment.
Treatment for NASH has shown positive results at 90 days with improvement in biometric parameters such as change in BMI and liver lobe size at 48 weeks after being treated with 2100 mg/day of silymarin. The 48 weeklong treatment at such a high dosage yielded improvements in liver histology, noninvasive markers of hepatic fibrosis and liver function parameters vs. baseline with silymarin but not with placebo (2).
Treatment with silymarin and its ability to promote the regrowth of the liver cell is one of the ways that it can help in the recovery of NASH. The treatment of choice is preventive lifestyle changes, but they are not for everyone.
Drug Induced Liver Toxicity
The treatment of drug induced liver toxicity met with controversy with study results dependent on the ability of milk thistle to lower superoxide dismutase, an enzyme that breaks down toxic molecules. According to the literature, prophylactic therapy reduced the possibility of developing drug induced liver toxicity more effectively than it treated it after the fact. Contrarily, a German study showed that silymarin improved quality of life scores (i.e. fewer cases of vomiting and nausea) and lowered liver enzyme levels after two months of treatment in patients already injured from toxin exposure (2).
Taking a specific extract of milk thistle and other herbs (Iberogast) taken orally for four weeks (1 ml 3x day) seemed to relieve the severity of acid reflux, epigastric pain, cramping, nausea and vomiting compared to placebo (3).
A human trial containing 420 mg in 3 divided doses for 12 weeks was effective on a study of thalassemia patients, and most clinicians agree that taking milk thistle in addition to iron chelation therapy is more effective than chelation therapy alone (5). A combination of milk thistle, diet and exercise reduced cholesterol by 33.6 mg/dl compared to diet and exercise alone at 12 months. While milk thistle is used for other conditions, most human trials that show effectiveness run for several weeks (5) and most need more human data.
While effects on some parameters may be seen in weeks, more than likely, chronic conditions will need to be treated for several months to achieve the best outcome. Duration of treatment of up to 41-48 weeks is considered safe (2, 5).
Milk thistle needs to be taken 30 minutes prior to a meal. It is not recommended to drink tea in the form of a beverage. When combined with phosphatidylcholine, thebility is increased.
Natural Wellness’s UltraThistle contains a patented, highly-absorbable form of milk thistle called Silybin Phytosome. Silybin Phytosome combines silybin – the most active and beneficial ingredient in milk thistle which is responsible for 50% to 70% of milk thistle’s therapeutic benefit – at a molecular level with phosphatidylcholine, a phospholipid which is the same material found in cell membranes.
The duration of therapy is inconsistently documented in the literature most probably due to the different bioavailability’s of the formulas used in the older studies, poor study design and low methodological quality (3).
The need for treatment duration can be affected by variations in factors.
- The degree of damage to the cells at the beginning of the treatment.
- There are problems from lack of blood sugar control.
- There is either presence or absence of cancer.
- There is still ongoing toxin exposure.
- The product’s bioavailability is a factor.
The degree of effectiveness relative to treatment duration is unclear in the literature, but seems to have deeper functional meaning for chronic disease and longer-term use of a standardized extract of silybin mixed with phospholipids.
- Kaur, A.K. (2011). Milk thistle: A review. International Journal of Pharma. Research and Development-Online (IJPRD), 3(2):1-10. Retrieved from https://scholar.googleusercontent.com/scholar?q=cache:gVy7johPQVYJ:scholar.google.com/+milk+thistle+duration+for+effectiveness&hl=en&as_sdt=0,23
- Gillessen A., H. Hartmut and Schmidt, J. (2020). Silymarin as supportive treatment in liver diseases: A narrative review. Adv Ther. Retrieved from https://doi.org/10.1007/s12325-020-01251-y
- Silybum marianum, synonym Cardus marianum. (n.d). TRC Natural Medicines. Retrieved 3/9/2020 from https://naturalmedicines.therapeuticresearch.com/databases/food,-herbs-supplements/professional.aspx?productid=138#scientificName
- Kuhu, R. and Iyer U. (2019). Role of silymarin in the management of non-alcoholic fatty liver disease: Time to clear the mist. Functional Foods in Health and Disease, 9(5):126-133. Retrieved from DOI: 10.31989/bchd.v2i5.622
- Milk thistle. (2019, March 1). Drugs.com. Retrieved 3/12/2020 from https://www.drugs.com/npp/milk-thistle.html
About the Author
Kathy Shattler is a registered nurse.
Kathy Shattler has over 25 years of experience as a registered dietitian and runs her own Telehealth Clinic. She graduated with a Master of Science degree in Human Nutrition from Michigan State University and has a lot of experience in both clinical nutrition and public health. She is considered to be a pioneer in her profession and continues to strive for excellence in public health education.