top of page
  • Writer's pictureJoan Rothchild Hardin

Goldenseal & Milk Thistle For Diabetes

I inherited a genetic predisposition for Type 2 diabetes from both my maternal grandfather and paternal grandmother and developed mild gestational diabetes toward the end of my pregnancy in 1976 which resolved after the birth of my son.  My fasting and non-fasting glucose levels were within normal range since then but then my A1C became slightly high about a year ago – so David Miller, MD (the nutritional supplements guru at LifeThyme Market on 6th Avenue in Greenwich Village) suggested I take two phytonutrients, milk thistle and goldenseal, both of which have been found to be as effective for preventing and controlling  diabetes as any of the pharmaceuticals typically prescribed.

As with the colon and breast cancer history in my family, I have no intention of allowing that inherited tendency for diabetes to express itself. I always prefer nutritional supplements over pharmaceuticals (which my body generally has a hard time with) so was very interested in Dr Miller’s suggestions.

(In case you’re interested, at the bottom of this post I’ve included the brands and dosages I’m taking.) A NOTE ABOUT GENETICS VS EPIGENETICS:

A reminder that inheriting a predisposition for Type 2 diabetes – or any other condition or disease – does NOT mean you will necessarily develop the disease. You have a choice in whether you allow your DNA to become your destiny.

“Chronic diseases, especially autoimmune ones, are only 25% determined by genetic inheritance. The other 75% is affected by other factors. It’s a matter of genetics vs epigenetics. You may have a genetic predisposition for diabetes but also have a large say in whether your DNA expresses that predisposition in your body.

“If we know that both the composition and abundance of micro-organisms living in our guts  change over the course of a lifetime, shouldn’t it be possible to learn how to make deliberate changes to our gut microbiome – changes that prevent diabetes from developing even if we have a genetic predisposition for it?” (Hardin, 2015B)


“We know from twin studies, from identical twin studies, that 25% of autoimmunity is your genetics, and 75% is from the environment. … So that’s an enormous amount that we have control over and can influence.”

Amy Myers, MD. (Sanfilippo, 2015)



Native to North American, GOLDENSEAL has a long history as a medicinal plant among Native Americans, who used it as an herbal antibiotic and immune system enhancer to treat inflammatory conditions such as respiratory, digestive and genitourinary tract inflammation induced by allergy or infection. The Cherokee used it to treat cancer, general debility, and dyspepsia; to stimulate a poor appetite; and as a tonic and wash for local inflammations. The Iroquois made a decoction of its roots to treat whooping cough, diarrhea, liver disease, fever, sour stomach, flatulence, pneumonia, nausea, heart trouble, and as an emetic. They also prepared it as an infusion with other roots for use as drops to treat ear ache and as a wash for sore eyes.  They mixed it with bear’s grease for use as an insect repellent. Native people also used goldenseal’s yellow roots as a stain and dye. (Morgenstern, undated) & (HerbWisdom, 2016)

Among the numerous health benefits offered by goldenseal is reducing blood glucose levels in people with Type 2 diabetes. Berberine (an active compound in goldenseal) is responsible for this beneficial effect. “In a preliminary trial, supplementation with 1 gram per day of berberine … for two months significantly lowered blood glucose levels in patients with type 2 diabetes.” (University of Michigan Health System, 2015)

Goldenseal’s other health benefits include its antimicrobial, antibacterial, antifungal, immune enhancing, digestive stimulating actions. See this 2015 article on Goldenseal by the University of Michigan Health System for more information.


See the Herbal Encyclopedia’s article on goldenseal for a full list of it’s key actions and key components.


For the MDs reading this post and others of you who are interested in understanding the mechanism by which the berberine in goldseal helps control diabetes, I recommend taking a look at Frank Shallenberger’s article Can This Herb Completely Replace Drugs for Type-2 Diabetics?

Dr Shallenberger is Editor-in-Chief of Second Opinion Newsletter and Second Opinion Health Alert. He is a graduate of the University of Maryland School of Medicine and received his post graduate training at Mt Zion Hospital in San Francisco. He has been practicing medicine for over 43 years and is board certified by the American Board of Anti-Aging Medicine.

This is an excerpt from his article:

“So from now on, in my diabetic patients with low insulin levels, you can bet that I will be starting them right away on berberine.

“My guess from (my diabetic patient’s) experience and also from articles like the one I mentioned here is that many patients who are taking insulin or drugs designed to increase insulin may be able to either stop them or reduce them after starting berberine.

Better than metformin for diabetes

“Now I’d like to tell you about another study that proves this. In fact, this study shows that berberine might just be the best medication there is, natural or otherwise, for diabetes.

“This study looked at the effect of berberine on 36 patients. All of them were newly diagnosed cases of type-2 diabetes.

“Half of the patients took 500 mg, three times daily of the drug metformin (also known as Glucophage). The other half took berberine (berberine hydrochloride) in the same dose – 500 mg, three times a day. Then the researchers measured the participants’ blood sugar levels for the next three months. Here’s what happened: In terms of blood sugar control, both treatments worked equally as well. The fasting blood sugars went down 30%. And the sugar levels after eating (called the post prandial levels) went down even more – 45%.

“But here’s the really astounding thing about berberine. All of this happened within the first two to four weeks of taking the treatment. And unlike metformin, there were no side effects at all in any of the patients taking berberine. In addition to the sugar levels, the A1c levels went down as well – a full 20%. That may not sound like a lot. But it’s a very significant improvement.

“In addition to the remarkable effects it had on blood sugar control, berberine had another important effect that metformin did not have.

“Triglycerides are the fats found in the bloodstream that the cells metabolize for energy. Since type-2 diabetics do not effectively burn fat (that’s why they get fat), their triglyceride levels are always elevated.

“In this study, those patients taking berberine had a reduction in their triglyceride levels of 21%. Those taking metformin had no reduction at all. This indicates that berberine not only improves sugar metabolism, it also improves fat metabolism. This might make berberine the most effective overall medication for diabetes that exists today, including pharmaceuticals. In fact, the authors of the study stated that berberine ‘can serve as a new class of anti-diabetic medication.'”



Research has demonstrated that another phytonutrient, MILK THISTLE, improves insulin resistance, a main characteristic of Type 2 diabetes. Silymarin, an anti-inflammatory and anti-oxidant, (the principal active constituent in milk thistle),  is responsible for this beneficial effect.

The milk thistle plant is native to Europe, the Middle East, North Africa, and parts of the Mediterranean. It has been used medicinally for thousands of years  – as a remedy for snakebites; liver ailments; depression; irregular menstruation; varicose veins; kidney, liver, and spleen problems. In Traditional Chinese Medicine it is used for clearing heat and removing toxicity. (Milk Thistle Resource, 2014)

Human and animal studies confirm that milk thistle protects against metabolic syndrome – cluster of conditions (including high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels) that increase the risk of heart disease, stroke, and diabetes.

Milk thistle also protects against against fatty liver disease and neutralizes the hepatitis C virus. And, unlike most pharmaceuticals, milk thistle extracts “benefit liver function by multiple mechanisms of action. In this way, milk thistle extracts provide broad-spectrum benefits for supporting overall health.

Milk thistle’s components help the liver cleanse the blood of toxins and shield liver cells from the barrage of free radicals, fats, sugars, and other compounds that lead to common liver ailments.” (Nevis, 2016)

For more detailed information on milk thistle and how it works, see this excellent article in Life Extension Magazine Mediterranean Herb Guards Vital Liver Functions  and also  Milk Thistle Extract Could Help Diabetes Control.



There is also evidence that milk thistle protects against a variety of common cancers. “Laboratory studies demonstrate that silymarin stabilizes cellular membranes, stimulates detoxification pathways, stimulates regeneration of liver tissue, inhibits the growth of certain cancer cell lines, exerts direct cytotoxic activity toward certain cancer cell lines, and possibly increases the efficacy of certain chemotherapy agents.” (National Cancer Institute, 2016)

For more information on the use of milk thistle in the prevention of cancer and as a treatment and adjunct agent for people who have cancer, see Read About the Numerous Anti-Cancer and Protective Effects of Milk Thistle Extract (Silymarin) and Milk Thistle (PDQ®)–Health Professional Version.



In researching this post, I came across a variety of cautionary advice regarding goldenseal and milk thistle supplements: GOLDENSEAL

“Large doses should be avoided. Goldenseal stimulates contraction of the uterus and thus should be avoided during pregnancy. It may also raise the blood pressure and should not be used by people who suffer any kind of cardiac problems.” (Morgenstern, undated)

“If taken over an extended period of time, it can cause digestive disorders, mucous member irritation, constipation, excitatory states, hallucinations, and occasionally deliria. Goldenseal is habitually overused, much like conventional antibiotics, and similarly, for inappropriate reasons. Most herbalists recommend that it be used for no more than three weeks at a time without a break of at least two weeks in between.

It may cause a decreased vitamin B absorption rate with higher doses of the herb.” (Cloverleaf Farm, 2016) MILK THISTLE

“Usually, milk thistle causes few, if any, serious side effects. Studies show that it’s safe when taken for up to 41 months.

Milk thistle may cause diarrhea. More rarely, it may cause nausea, bloating, gas, and upset stomach.” (WebMD, 2005-2016)

Side Effects & Precautions (Lewanda, 2013):

  • Milk thistle is well-tolerated with few, if any, serious side effects.

  • May cause: diarrhea, nausea, bloating, gas, upset stomach.

  • Drug interactions are possible with milk thistle extracts. As with all polyphenol flavanoid compounds, silymarin is metabolized by the liver enzyme “Cytochrome P-450” which also is responsible for metabolizing many pharmacologic drugs. Taking silymarin along with any of those drugs may increase the toxicity of those drugs. Studies show, however, that the dose of milk thistle extract that inhibits Cytochrome P-450 is high and not likely able to be achieved with oral intake. One exception was recently identified with a potential interaction with the blood thinner, warfarin (milk thistle extract slowed the metabolism of warfarin, increasing the risk of bleeding.)

  • If you have an allergy to ragweed, chrysanthemums, marigolds, or daisies, you should avoid milk thistle. Milk thistle may cause a rash or lead to severe allergic reaction.

  • Since milk thistle may mimic the effects of estrogen, some women should avoid this herb. This includes women who have fibroid tumors or endometriosis. Additionally, women with breast, uterine, and ovarian cancers should not take milk thistle. (per WebMD)



Of course, preventing diabetes is preferable to trying to control it after it has developed. See Prediabetics Have Fewer Gut Bacteria (Hardin, 2015B) for more information. THE GOLDENSEAL & MILK THISTLE SUPPLEMENTS I’M TAKING

These are the brands and dosages I take:

Goldenseal (Natures’s Way)           — 1 after breakfast/1 after dinner

Milk Thistle Plus (Enzymatic)         — 1 after breakfast/1 after dinner

My body has been doing well on these phytonutrient supplements in the months I’ve been taking them. A recent retest of my blood glucose and A1C  levels found both are stable and good, results  for generalized inflammation in the body [C-Reactive Protein and Erythrocyte Sedimentation Rate (ESR)] are negative, and my liver and kidney functions are good – even though I’ve added grains (organic as much as possible) back into my diet, returned to eating chocolate (organic) pretty much every day, and gained some weight.

I like that both goldenseal and milk thistle provide health benefits beyond keeping my body from becoming diabetic.



Cloverleaf Farm. (2016). Goldenseal. Herbal Encyclopedia. See:

Daniells, S. (10/30/2006). Milk thistle extract could help diabetes control. See:

Hardin, J.R. (2014). Is It Necessary To Express an Inherited Trait? See:

Hardin, J.R. (2015A). Dark Circles Under Your Eyes? Improve Your Gut Bacteria.

Hardin, J.R. (2015B). Prediabetics Have Fewer Gut Bacteria. See:

HerbWisdom. (2016). Goldenseal (Hydrastis Canadensis). See:

Lawenda, B.D. (2013). Read About the Numerous Anti-Cancer and Protective Effects of Milk Thistle Extract (Silymarin). Integrative Oncology Essentials. See:

Milk Thistle Resource. (2014). Milk Thistle History. See:

Morgenstern, K. (undated). Goldenseal in Profile. Sacred Earth. See:

National Cancer Institute. (2016). Milk Thistle (PDQ®)–Health Professional Version: Overview. See:

Nevis, L. (2016). Mediterranean Herb Guards Vital Liver Functions. See:

Sanfilippo, D. (2015). Podcast Episode #178: The Autoimmune Solution with Dr. Amy Myers. See:

Shallenberger, F. (2014). Can This Herb Completely Replace Drugs for Type-2 Diabetics?

University of Michigan Health System. (2015). Goldenseal. See:

WebMD. (2005-2016). Milk Thistle: Benefits and Side Effects. See: © Copyright 2016. Joan Rothchild Hardin. All Rights Reserved.

DISCLAIMER:  Nothing on this site or blog is intended to provide medical advice, diagnosis or treatment.

Comments submitted prior to 8/25/2021

Am a type 2 diabetic & also high blood pressure, i was diagnosed 7 months ago with diabetes, within2 months i change my diet exercise and was off my meds. By taking cinnamon, Gymnema, chromium, & also berbine 100 mg Quercetin dihydrate 100 mg & gynostemma 450 mgs & multivitamin. So am asking is it safe for me to take the golden seal

& milk thistle. Am looking to eleminate & or shorten my list of pills am taking to only take the ones i really need to control my diabetes. Your opinion i will be greatly appreciated. Thank you.

Lovely louis

In reply to Lovely louis

Lovely Louis,

I’m not qualified to answer your question but can point out that berberine is the active substance in goldenseal so you’re already taking it. My suggestion is to read through the articles listed under REFERENCES at the end of my post and, if you haven’t already done so, also do a Google search for ‘diabetes alternative treatment’.

Joan Hardin


Rated 0 out of 5 stars.
No ratings yet

Add a rating
bottom of page