Milk thistle - anything to be aware of? - Thyroid UK

Thyroid UK

137,155 members160,837 posts

Milk thistle - anything to be aware of?

JonnyA profile image
7 Replies

A recent blood panel came back with slightly raised liver enzymes (marginally above the range), for reasons I am looking into.

I have read about the benefits of milk thistle supplementation with respect to helping with both liver and thyroid matters.

On the whole, the consensus seems to be that it is a pretty healthy supplement, though I have also read some contradictory articles which suggest milk thistle can have adverse effects on both the liver and thyroid.

Is there anything I should know before going ahead?

Thanks!

Written by
JonnyA profile image
JonnyA
To view profiles and participate in discussions please or .
Read more about...
7 Replies
helvella profile image
helvellaAdministratorThyroid UK

Yes - there is something to know!

Suggest you have a look at these posts:

Silychristin, a Flavonolignan Derived From the Milk Thistle, Is a Potent Inhibitor of the Thyroid Hormone Transporter MCT8

healthunlocked.com/thyroidu...

Milk thistle alters thyroid hormone transport

healthunlocked.com/thyroidu...

Fruitandnutcase profile image
Fruitandnutcase

I thought of that a while ago then after reading up on it I decided against it - unfortunately I can’t remember exactly why but I’m sure if you read up on what helvella has posted you’ll see for yourself.

Clara4741 profile image
Clara4741

I've taken it for years since I worked with a FM Practitioner and Medical Herbalist. I take 5 caps per day spread out with my meals. It is totally safe and you can take a fair bit of it. I'm based in the UK and use the Cyoplan brand which is clean and very reasonable to buy. I have Hashimotos but it is fine to take Milk Thistle. Just keep it away from meds because it could make them less effective due to Milk Thistle helping detoxification. That's the only thing to be aware of but no dangers.

tattybogle profile image
tattybogle in reply to Clara4741

"I have Hashimotos but it is fine to take Milk Thistle. Just keep it away from meds because it could make them less effective due to Milk Thistle helping detoxification. That's the only thing to be aware of but no dangers"

I don't know about "may make them less effective due to milk thistle helping detoxification."..... but as far as i can understand it , the issue is that it affects MCT8 . which is involved in thyroid hormone transportation into cells ( i think ?. the science is a bit over my head to be honest )

So ,before advising thyroid patients there are "no dangers" you should read this .. i tried.... but "it's complicated "

academic.oup.com/endo/artic...

"Unfortunately, there is likewise an alarming aspect to this finding. SY is an over-the-counter drug, which is known for various hepatoprotective properties. It is easily available from many commercial sources, and consumption of this drug regarding dosage and frequency is not controlled by any instance. From the literature, SY is broadly accepted as a safe herbal dietary supplement, and a dose of 420 mg/d is regarded to be well tolerated (20). However, many studies are using SAB because it is the main compound of SY, and most positive effects are referred to it. In our experiments, SAB turned out to be a much weaker inhibitor of MCT8. Studies on SAB might therefore strongly underestimate the potential risk of SY regarding the HPT axis. Even if SAB is not critical regarding its effects on THTTs, most products found, eg, in internet stores, are depending upon the herbal, natural preparation of SY and are therefore in a composition including SC in undefined and potentially harmful concentrations.

Our results question the postulated safety of these preparations.

Indeed, comprehensive pharmacokinetic studies measuring the plasma concentrations of SY compounds in three healthy volunteers underline a possible physiological impact of SC. After a single oral administration of 600 mg milk thistle extract, SC reached a peak plasma concentration (after 1–3 h) of 53.8 ng/mL. This is equal to approximately 110 nM and in the range of our in vitro IC50 values (29). Because TKIs have significant effects on the TH axis with plasma levels, even 1 order of magnitude below their IC50 (7), an in vivo effect of SC is even more likely.

Dysregulations of the TH axis are not always resulting in overt and acute states of disease, but a constant dysregulation will likely lead to adverse effects in the long run. SC might significantly block TH import into target cells, causing metabolic and developmental dysregulations. By its high specificity, this will happen in an organ- or even cell type-specific manner, eg, in astrocytes.

Several rat studies report beneficial effects on oxidative stress markers in the young and adult brain, implying that SY is able to cross the blood-brain barrier and enter the central nervous system (30, 31). Because THs are, for example, important for proper development of the human brain, the use of SY during pregnancy should be discouraged until the proof of its safety. Also, people with manifested diseases of the thyroid gland, eg, hypo- or hyperthyroidism, are at risk by regular consumption of SY-containing preparations.

Our data strongly suggests attentive care on the use of this herbal drug. We would also strongly recommend that studies on SY-use and -safety should include a thorough analysis of the HPT axis and a more intensive characterization of the metabolism of SY and its components."

Brightness14 profile image
Brightness14

Years ago many people took milk thistle to help the liver. 2 Brazil nuts a day , i.e. selenium helps too, also beetroot.

Lynneypin profile image
Lynneypin

I take one a day. I have impaired liver function and I’m pretty convinced it helps. I was due a liver biopsy but have escaped that trauma….I can’t say if it’s because of the milk thistle, but my consultant said a lot of his patients swear by it.

Everdean profile image
Everdean

I used to take Milk thistle with no bad effects. My nails certainly improved when I was on it they were unbreakable. My hair was better too.. But a herbalist said it could interfere with uptake in meds inc. thyroid so I stopped.But my nails and hair are not in a good state and was thinking of going back on it.

I think when I was on it before I knew about any negatives I didn't notice a problem.

Still, I'm erring on the side of caution and not taking it as yet.

You may also like...

Milk thistle alters thyroid hormone transport

ca/2022/01/16/milk-thistle-thyroid-transport/ I'll not try to summarise - much better to go and...

Milk Thistle for reducing reverse T3

Hi, I wish to try milk thistle supplements to lower my RT3. I read that I need to ensure I use seeds

Can I take milk thistle while taking levothyroxine?

I have been taking milk thistle but have today for the first time been asked if I am on any meds...

selenium and milk thistle

Is it worth switching to non organic milk for iodine?

skimmed Organic Milk, and apparently organic milk contains far less iodine than the standard milk....