TUDCA vs Milk Thistle: The Liver Support Showdown

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Your detoxification organs – your liver, kidneys, and colon – never take a break. They’re like the unsung heroes of your body, tirelessly behind the scenes, neutralizing and eliminating environmental toxins, excess hormones, free radicals, and other nasties from your system before they cause issues.

Your liver does the bulk of this work thanks to its two-phase detoxification system. Nothing gets passed that bad boy. 

That said, even the most hard-working organs need support sometimes. Especially if you’re pushing too hard with alcohol or other *cough* recreational activities. Not judging; just saying.

In the quest for a healthy liver, two supplements stand out: TUDCA and milk thistle. Both have impressive benefits, and we’ve reviewed them individually before. But how do they stack up against each other?

Today, I’ll compare the benefits, uses, dosages, and risks to help you answer the age-old question, “Should I take TUDCA or milk thistle?” Plus, I’ll point you toward the best supplements on the market.

Let the showdown begin.

What is TUDCA?

TUDCA – short for tauroursodeoxycholic acid – is a water-soluble bile acid naturally made in the body in small amounts. It’s like another bile acid called ursodeoxycholic acid (UDCA) but with an added taurine (hence the T).

First derived from the bile of black bears (yep, you read that right), TUDCA has been used in traditional medicine for centuries to support bile production and liver health.

While bears are still cruelly hunted and “farmed” for their bile salts in some places, no bears were harmed to make any supplements we recommend. TUDCA is synthetically derived nowadays.

How Does TUDCA Work?

As a bile acid, TUDCA stimulates healthy bile flow from the liver to the gastrointestinal tract.

If you need a reminder, bile helps you digest and absorb fats and vitamins like A, D, and E. Your liver makes it, and your gallbladder (a tiny organ above your liver) stores it.

TUDCA prevents the buildup of toxic bile acids, which lead to gallstones and liver damage.

Health Benefits

TUDCA is known for reducing liver enzymes and helping with annoying conditions like cholestasis, where bile gets backed up in the liver.

It may also stabilize membranes and reduce stress in a part of the cell called the endoplasmic reticulum (1). This organelle is important for things like protein folding and fat metabolism.

Endoplasmic reticulum stress may contribute to insulin resistance. And this may explain why a study found TUDCA increases insulin sensitivity in muscle and liver tissue by up to 30%.

What Is Milk Thistle?

Milk thistle, scientifically known as Silybum marianum, is a prickly Mediterranean plant with distinctive purple flowers with white marbling. Crush it, and you’ll see a milky sap – hence the name.

tudca vs milk thistle


How Does Milk Thistle Work?

Milk thistle works through various mechanisms, including liver protection, antioxidant and anti-inflammatory properties, and cholesterol regulation.

The benefits of milk thistle are down to silymarin, a complex mixture of flavonolignans compounds with antioxidant and anti-inflammatory properties. Silybin, making up 50-70% of silymarin, is the real MVP.

Most quality milk thistle supplements contain a standardized dose of active silymarin.

Health Benefits

Silymarin neutralizes harmful free radicals that can damage liver cells. It may reduce liver inflammation and damage from health conditions like alcoholic liver disease, fatty liver, and hepatitis.

In addition to promoting a healthier liver, this systematic review and meta-analysis found milk thistle extract may regulate blood sugar levels in people with diabetes. This could make it a potential adjunct treatment for type-2 diabetes.

Furthermore, a small study found silymarin daily may improve lactation in breastfeeding women. But we need more research to understand the exact mechanism.

Now, let’s compare the two.

TUDCA vs Milk Thistle for Liver Support

While neither TUDCA nor milk thistle are magic hangover cures, both are well-known for supporting liver health. However, they work differently, so understanding their specific benefits and applications can help you pick the right liver support supplement.

TUDCA is better for supporting healthy bile flow, allowing the body to digest fats more efficiently. It may reduce the risk of liver conditions like cholestasis, where bile flow from the liver to the small intestine slows down and creates toxicity.

On the other hand, milk thistle is touted as a powerful liver detox herb, but the research isn’t solid on that. That said, its antioxidant firepower is pretty special – it may even boost the activity of your master antioxidant, glutathione peroxidase (2). This is important because the liver needs antioxidants to neutralize toxins and render them harmless.

Overall, milk thistle acts as a shield, defending the liver cells from toxins and aiding in liver regeneration.

TUDCA vs. Milk Thistle for Liver Enzymes

Serum liver enzymes are markers of liver function. If you’ve been given a blood form from your doc, you may be familiar with terms like alanine transaminase (ALT) and aspartate transaminase (AST). If not, maybe it’s time for your annual checkup.

Anyway, elevated liver enzymes might signal liver damage.

TUDCA and milk thistle could lower these enzymes, but TUDCA seems more reliable in studies (34).

TUDCA vs. Milk Thistle for Liver Disease

Milk thistle and TUDCA cannot treat or cure any liver diseases. That said, both supplements have their unique roles. 

As mentioned, TUDCA is known for treating cholestasis. However, research shows it may also reduce liver damage in liver cirrhosis and chronic hepatitis (5).

Milk thistle is used for general liver support and potentially aiding liver regeneration. Its antioxidant and anti-inflammatory effects may improve cirrhosis and slow the progression of nonalcoholic fatty liver disease (6). Milk thistle extract may also reduce the risk of complications in alcoholic liver disease, hepatitis, and drug-induced liver injury – but the evidence is limited and generally low-quality (7).

It goes without saying that we need more research on TUDCA and milk thistle for liver disease.

TUDCA vs. Milk Thistle for Cholesterol Regulation

Cholesterol regulation is another area of interest for both TUDCA and milk thistle.

According to this study, and this study, milk thistle extract may support heart health by reducing blood lipids like low-density lipoprotein (LDL), total cholesterol, and triglycerides.

TUDCA may support healthy cholesterol levels by promoting bile flow, which helps fat digestion and absorption. But clinical research on this is limited. 

Milk thistle wins this battle.

TUDCA vs. Milk Thistle for Liver Health in Athletes

Overdoing fitness supplements, a high-protein diet, intense training schedules, ongoing stress, and anabolic steroids put much extra pressure on the liver.

TUDCA, more than milk thistle, is popular among bodybuilders for flushing out toxic stuff during competition prep (yeah, steroids). While some people feel it gives them leeway during competition season, there isn’t much evidence to back this up. Don’t count on it to reduce steroid side effects. Make sure you’re working with a doctor.

Overall, these compounds target different aspects of liver function. TUDCA excels in bile flow and digestive support, while milk thistle offers powerful antioxidant support.

They won’t magically make your liver resilient to steroids, alcohol, or a junk food diet. But they may offset some of the damage of living in a world that takes a toll on the liver.

Comparison of Usage and Dosage

The recommended dose for both supplements varies based on the product and your overall health needs.

When it comes to TUDCA, most supplements offer 250-500 mg per serving for general liver and digestive support. However, studies have also used up to 1500 mg safely. Overall, you should start with a lower dose and increase it gradually as tolerated. Plus, TUDCA is best taken with fatty meals to support digestion.

Milk thistle is a bit trickier since it’s a herb. Typical doses are 150-300 mg of silymarin taken two to three times daily. You can find it in capsules, tinctures, and teas, making it versatile and easy to add to your wellness routine.

Comparison of the Risks and Potential Side Effects

TUDCA and milk thistle have good safety profiles and are well-tolerated when taken at the suggested doses. That said, like all supplements, both have potential side effects.

Some people experience minor stomach pain, nausea, diarrhea, bloating‌, muscle cramps, and headaches. But it’s rare and usually a case of taking more than the recommended dosage. Higher doses of TUDCA may cause diarrhea, which makes sense as it’s a bile acid.

If something feels off, stop taking it and consult your healthcare provider for advice. Furthermore, since they work on the liver, this may impact drug metabolism. Speak to your doctor if you’re on prescription medication.

So, which one should I take?

In this TUDCA vs. milk thistle showdown, there’s no clear winner or loser. It’s all about what you need. 

TUDCA is the star for helping with bile flow, digestion, and lowering liver enzymes. Milk thistle gets the win for antioxidant protection, reducing inflammation, and regulating cholesterol. 

However, the liver supplement you choose depends on your health goals, preferences, and pre-existing conditions. Heck, you may even find a combination of the two is where it’s at.

Think about what you want to achieve. Whether you’re dealing with a chronic issue, partying a bit too hard, or need to keep things running smoothly, your health goals can help you align with the right supplement.

As always, talk to your healthcare team before starting any new supplement – especially if you’re taking chronic medication or are pregnant or breastfeeding. In addition, these supplements are not a treatment or cure for any conditions. Instead, look at them as adjunct therapies.


Got burning questions about these liver-support superheroes? We’ve got you covered.

What is the difference between TUDCA and milk thistle?

TUDCA is a naturally occurring bile acid, while milk thistle is a herbal extract with potent antioxidant properties.

Can I take TUDCA and milk thistle together?

There’s no known interaction between TUDCA and milk thistle. They have different mechanisms of action and are generally safe to use together.

Liver support supplements often combine the two – like in the case of HumanX TUDCA+.

That said, taking both might be overkill in some circumstances, so speak to your healthcare provider first.

Are TUDCA and milk thistle safe for long-term use?

To be frank, both TUDCA and milk thistle are more likely to show benefits when used over weeks or months rather than over the short term.

TUDCA has been used safely for up to a year in studies, but we need more info on the long-term effects of both supplements.

Who shouldn’t take TUDCA?

Overall, TUDCA is a low-risk dietary supplement because it’s a compound found naturally in the human body.

But we need more research for pregnant and breastfeeding women, so check with a healthcare provider.

Who shouldn’t take milk thistle?

Milk thistle is part of the Asteraceae family, so it might not suit you if you’re allergic to dandelion, ragweed, or daisies. Again, ask your doc before starting any new supplement.

What else can I do to support liver health?

Your liver is designed to detoxify – it doesn’t necessarily need health supplements to do its job. And don’t get me started on the ‌‌‌”liver cleanse” scam.

TUDCA and milk thistle can help, but they’re not the whole story. You should be looking after your detox pathways by staying hydrated, exercising, sleeping well, eating lots of fruits and veggies (organic when possible), consuming high-quality protein every day, and going easy on the booze. Only look at supplements once you’ve covered these bases.

Other liver-support herbs and nutrients we like include glutathione and NAC.

What are the best TUDCA and milk thistle supplements?

We have affiliate links throughout this article, which means we receive a commission if you buy from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying banner ads. Those suck.

I thought you’d never ask.

Our number #1 picks are Morphogen TUDCA and Quicksilver Scientific Liposomal Milk Thistle for their optimal bioavailability and absorbability.

You can find the rest of our recommendations in our articles on the best TUDCA supplements and the best milk thistle supplements.

About the Author

Katherine is a South African-born nutritionist, freelance wellness writer, and rooibos tea enthusiast (iykyk). When she's not researching new "biohacking" trends and writing for her clients, you'll find Katherine swimming at a local Cape Town beach or practicing breathwork at any opportunity.

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