May 2026

Polyphenols in herbal medicine

• Week 1: Polyphenols in herbal medicine
• Week 2: Hawthorn – A Heart Feeling Herb
• Week 3: Milk Thistle – Liver First Aid
• Week 4: Goldenrod – The Golden Healer

Milk thistle is a unique and beautiful addition to a herb garden. Extracting the seeds from the thistle is a painful work, though. 

Milk Thistle – Liver First Aid

Botanical Family: Asteraceae

Part used: The seeds

Degree

 3rd degree, Milk thistle is strictly an herbal remedy that shouldn’t be used as food (first degree) or to season food (2nd degree). However, it is not considered a low dose botanical (4th degree)

Description

Milk thistle is a tall, often 3 to 4-foot plant with thick, branched stems, leaves, and flower heads that are covered with a thin down.

Leaves: Large, long, shiny, and wavy, with white marbled veins and spines on the edges.

Flowers: Large, purple flower heads, protected by spiny, thorny bracts.

Seeds: Hard, smooth, and shiny with a white, silky pappus.

Growing 

Milk thistle is native to the Mediterranean but is now widespread all over the world. In Greece, it is considered a weed and is found on roadsides and waste ground. 

In the wild, milk thistle grows as a biennial, but in cultivation it is an annual herb. It prefers high fertility soil. 

Before seeding milk thistle, scarify the seeds with sandpaper. The seeds can be seeded directly into the bed in late winter as optimal germination occurs in 35-56 F. Seeds should be buried about ten inches deep, and spaced 24–36 inches apart. 

History and lore

Milk thistle has a long history of use as food and as medicine. 

Pliny the Elder (Gaius Plinius Secundus, 23–79 AD) recommended the juice of milk thistle mixed with honey as a remedy for “carrying off the bile.”

The Greek physician Dioscorides (40–90 AD) was among the first to document its healing properties. It was historically used to treat snake bites, liver conditions, and gallbladder issues.

17th-century English physician and author, William Westmacott, wrote in 1694: 

“It is a friend to the liver and blood; the prickles cut off they were formerly used to be boiled in the spring and eaten with other herbs; but as the world decays, so doth the use of good old things and other more delicate and less virtuous brought in.”

In 1597, herbalist John Gerard described it as “the best remedy against melancholy diseases.”

Energetic Architecture

Ruling Planet

Culpeper put milk thistle under Jupiter, a planet also associated with the liver. 

Jupiter is a radiating planet with no clear boundaries. Milk thistle can benefit people with non alcoholic fatty liver, a condition developed due to losing the protective boundary of satiation sensation, which leads to overindulgence in food, alcohol, or drug addiction. 

Ruling Element

The sturdy stem and sharp thistle point toward the fire element, which in the body manifests in inflammation. The antioxidant flavonoids in milk thistle have a cooling effect on inflammation, specifically in the liver. 

Taste: Bland, mildly bitter, and oily. 

Energetics

Temperature: Cooling

Fluids: Moistening

Tone: Neutral

Tissue State

Heat/Excitation – Milk thistle shines in hot, inflamed, or toxic liver states such as hepatitis or cirrhosis. It is beneficial for  medication-induced liver damage, acute (poisonous mushroom exposure), and chronic exposure to hepatotoxic substances.

Dry/Atrophy – The dryness might be secondary to the heat. Excessive chronic inflammation dries and irritates the tissue. Milk thistle is an oily herb that can “oil” the tissue, thus reducing the irritation. 

Specific Indications

Mathew Woods suggests milk thistle for:

“Dull heavy head, despondency, with coated tongue, lack of appetite, nausea”.  

Pharmacology

Silymarin – is the main compound in milk thistle and the one that is responsible for much of its action. Silmarin is a mixture of unique flavonoid complexes that contains silybin, isosilybin, silychristin, isosilychristin, silydianin, and silimonin. 

The highest concentration, comprising approximately 50–70% of the extract, is silybin, the major bioactive component of milk thistle. Various studies show silybin to have. Silybin has hepatoprotective effects and strong antioxidant properties that modulate a variety of cell-signaling pathways, thereby reducing the production of pro-inflammatory mediators.

Silybin undergoes phase Ⅰ and Ⅱ of liver detoxification, then binds to bile and is excreted with the stool. The elimination half-life of silybin is approximately 6 hours.

The bioavailability of silybin is lower when extracted with water and when absorbed orally. But it is significantly increased when extracted with ethanol or glycerin. Silybin is not easily absorbed by the gut lining; its absorption rate depends on the presence of other substances, such as fat, proteins, amino acids, cholesterol, or other flavonoids, which can mitigate its absorption. 

Other flavonoids – such as taxifolin, quercetin, dihydrokaempferol, kaempferol, apigenin, naringin, eriodyctiol, and chrysoeriol.

Fixed oils – including 60% linoleic acid, 30% oleic acid, and 9% palmitic acid.

Sterols – cholesterol, campesterol, stigmasterol, and sitosterol.

Sugars and proteins

Actions

Foundational action

Foundational action are associated with the energetic pattern and can be experienced viscerally in the body.

Milk thistle doesn’t fit perfectly into any of the six foundational actions (aromatics, astringents, demulcents, relaxants, stimulants, and bitters). It has some qualities similar to bitters, such as its cooling  effect and its supportive action on the liver and digestive function. However, most bitters are drying while milk thistle is moistening. 

Primary actions

Primary actions relate to organs, systems, or tissues.

• Hepatoprotective – The silymarin complex from milk thistle has shown a well documented protective action on the hepatocyte (liver cells).
• Cholagogue – stimulates bile flow, which supports fat digestion, helps move congestion out of the liver, and contributes to its alterative action.
• Alterative – herbs that improve metabolic waste clearance and tissue nutrition over time. Milk thistle’s alterative action is derived from its hepatoprotective and cholagogue effects. A healthier liver clears metabolic waste more efficiently. 
• Galactagogue – Increase milk production.

Secondary actions

• Secondary actions imply an end result without specifying energetics or the system affected. 
• Anti-inflammatory – The polyphenols and flavonoids reduce oxidative stress and inflammation.
• Antioxidant – The liver has high energy needs because it works nonstop. That is especially true when the body is exposed to toxins, whether in acute conditions such as poisoning or in chronic exposure, such as from drugs or alcohol addiction. The byproducts of constant energy production, inflammation, and phase Ⅰ and phase Ⅱ detox are increased free radicals. The polyphenols in milk thistle act as direct intracellular antioxidants; they scavenge free radicals in the hepatocytes and protect them from oxidative damage.
  

Organ affinity

• The liver
• The Kidneys

Clinical Pattern

While milk thistle has an affinity for the liver and does promote bile production, it is not the first herb to reach for when dealing with stagnant liver or when needing to encourage bile production. 

Milk thistle is best kept in the herbalist’s arsenal for when liver damage is likely. It has a profound lifesaving effect on people who have ingested poisonous compounds; Amanita muscaria mushrooms are a good example, or for people who suffer from chronic liver conditions that are degenerative, due to alcohol, drugs, or pharmaceutical abuse, or long term exposure to chemical toxins. Some of the conditions that can benefit from milk thistle are non-alcoholic fatty liver, hepatitis, cirrhosis, and liver failure.

What is oxidative stress?

At its core, oxidative stress occurs when the body produces more ROS (Reactive Oxygen Species) than its antioxidant capacity can neutralize. 

The mitochondria, your powerhouse for energy production, use the oxygen you breathe to generate energy. However, a small percentage of electrons escape the final process and end up as superoxide , a reactive oxygen species (ROS). 

In a healthy mitochondrion, only a small number of electrons escape the final process and become superoxide, a compound that is easily cleaned up by your innate antioxidants. 

The problem happens either in inflammatory conditions or when the mitochondria are not functioning well. In these cases, ROS is higher than normal and exceeds the capacity of the body’s built in antioxidant system.

When there aren’t enough antioxidants to neutralize ROS, they wreak havoc on your body. They damage DNA, which might lead to cancer; oxidize lipids, which can lead to cardiovascular conditions; oxidize nerves, leading to brain degenerative disease; and increase inflammation and metabolic conditions.  

Oxidative stress and the liver

The liver, being the body’s chemical lab, fulfills several crucial functions, including producing compounds (bile and cholesterol), storing compounds (glucose, iron, and more), and, of course, all its detox functions. The liver needs plenty of energy to carry out all these functions; therefore, the number of mitochondria in each one of its cells is higher than in most other organs in the body. Mitochondrial dysregulation and liver inflammation can lead to particularly high levels of ROS.

Silmarin from milk thistle has the double Wham, bam effect: it acts directly as an antioxidant, scavenging ROS and clearing them, but it also stimulates glutathione production in liver cells.

Hepatoprotective

Milk thistle’s effects on hepatocytes (liver cells) are profound and are attributed to three pathways:

Antioxidant – Silymarin has a direct scavenging effect because the flavonolignans have phenolic hydroxyl groups that can donate hydrogen atoms to neutralize reactive oxygen species. 

However, milk thistle’s profound antioxidant effect is derived from its effects on glutathione, our body’s built- in intracellular antioxidant. Silymarin upregulates glutathione synthesis in hepatocytes, increasing glutathione concentrations in cells under oxidative stress by 35-50%.

Anti-inflammatory – Milk thistle inhibits COX-2, a key inflammatory mediator. Silymarin also inhibits the NF-κB cascade, the inflammatory switch that initiates the release of inflammatory cytokines. 

Anti-fibrotic – Silybin reduces fibroblasts,  indirectly preventing  the deposition of collagen fibers that lead to the formation of liver scar tissue and the progression of liver injury

Metabolic conditions

Non alcoholic fatty liver is a common condition in people with type two diabetes and obesity. Increased caloric intake exhausts the choline reserve, which means the liver can’t export the excess fat to the body. The increase in liver fat leads to lipotoxicity, inflammation, and oxidative stress. The end result might be the formation of scar tissue in the liver (fibrosis) and, later, cirrhosis, a structural damage to the liver that alters its function.

A 1997 study found that a four month treatment with silymarin significantly decreased fasting blood glucose levels, mean daily blood glucose levels, and HbA1c. In addition, there was a significant decrease in fasting insulin levels and in the need to administer insulin. 

Other studies showed a reduction in total cholesterol, triglycerides, and LDL levels.

A 2012 study that compared the effects of silymarin and metformin on liver enzymes in people with nonalcoholic fatty liver found that although ALT and AST decreased in both groups, the reduction in the silymarin group was more pronounced. 

Combined treatment with vitamin E, silybin, and phospholipids improved liver health, particularly plasma markers of liver fibrosis and insulin resistance.

Anti-oxidant beyond the liver

The antioxidant effects of milk thistle expand way beyond the liver.

Nephropathy is one of the most common complications of diabetes mellitus and drug induced toxicity. A small percentage of silymarin is eliminated through the kidneys and bladder, where it has been shown to protect the kidneys from oxidative stress associated with diabetes mellitus. 

Milk thistle can play a dual role in cancer treatment. On the one hand, it shows promising effects in inhibiting cancer cells’ proliferation and motility; on the other hand, it helps protect the body, especially the liver, from the oxidative stress associated with chemotherapy.

The antioxidant and anti-inflammatory properties of silymarin have been shown to protect neurons following spinal cord injury and in brain degenerative conditions such as Alzheimer’s and Parkinson’s disease. 

Cholagogue

In liver conditions or in the absence of essential nutrients, bile production may drop significantly. Low bile production reduces fat absorption and the elimination of fat soluble toxins, such as hormones and excess cholesterol. Silymarin has cholagogue properties, increasing bile production and promoting bile flow.

Preparation and dosage

The elimination half-life of silybin is approximately 6 hours; therefore, frequent intake is important to maintain its circulation. 

Tincture dried seeds 1:30 70%A

Dosage 3-8 ml (0.6-1.6 tsp) 4 times a day

While the tincture works well for general liver support and maintenance, a standardized extract is needed for more complex liver conditions where you aim to increase silymarin’s bioavailability.

Silymarin’s bioavailability might be a little tricky because: 

• It is not easily soluble in water; therefore, teas are largely ineffective.
• It is found in relatively low concentrations in whole seed preparations.
• Silymarin is a complex of a number of flavonolignans (silybin, silydianin, silychristin) that behave differently. 

Standardized extract is the preferred preparation and is better absorbed when taken with fats and proteins; 140-180 mg of silymarin 3 times daily.

Safety

Milk thistle is generally a safe herb to use. 

As part of the Aster botanical family, milk thistle might trigger an allergic reaction in people who are allergic to other plants in the family, such as calendula and chamomi