The Unexpected Benefits (and Downsides) of Licorice Root Supplements

I’m sure many of us have fond memories of licorice candies as children.

Not me personally.

Friend introduced me to “dutch black” licorice when I was naught but a wee laddie far too vulnerable and innocent to taste Satan’s Salty Snack Stick.

I grew hair on my chest that day. Grade 2 was pretty hard thereafter.

Regardless, the Dutch and Canadians are buds so I can’t further comment on their clearly inferior taste in candies much; they grow nice tulips but no longer have a say in what crosses these two lips.

What I can comment on is medicinal usage of licorice root, though. You may be surprised to learn that it’s also found within the ranks of Traditional Chinese Medicine. Surprisingly high up too—a very popular plant.

Licorice root is seen as both an “adjuvant” of sorts in medicinal concoctions, being added to assist the effects of other components, and in its own right is a sweet tasting plant catered towards cardiovascular, respiratory, intestinal and endocrine disorders.

It was also used in Greek medicine and, to a degree, Indian medicine (Ayurveda). If every culture that came across licorice root used it for medicine in some manner… perhaps it is potent?

Oh, it is potent.

Not in the way you want though, unless you like cortisol for whatever reason.

Table of Contents

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• What Is Licorice Root?
• Why Do People Take Licorice Root?
• What Are The Benefits of Licorice Root?
• Does Licorice Root Have Any Side Effects?
• What Are The Benefits of Licorice Increasing Cortisol?
• What Is the Effective Dosage of Licorice?
• The Bottom Line on Licorice

What Is Licorice Root?

Licorice usually refers to one of two plants, Glycyrrhiza uralensis or more commonly Glycyrrhiza glabra, which have sweet-tasting roots.

The main component of the roots is glycyrrhizin, and it’s said to be 50 times sweeter than sugar. The sweet roots are actually where the genus got its name from. Glycos (sweet) and rhiza (root) forming the name latin name “Glycyrrhiza,” which turned into glycyrrhizin.

Because of the sweetness of the root it became quite popular as a candy and a decent trade commodity, then found medicinal usage in almost every region that it was traded to.

Nowadays we still use licorice flavoring as a candy even though table sugar has since beat it out as a cheaper and easier way to get the sweet taste we crave.

Why Do People Take Licorice Root?

To start with the most famous, and contentious, molecule in licorice let’s introduce glycyrrhizin!

Glycyrrhizin is a diglycoside, basically a storage form of the active molecule glycyrrhetinic acid (henceforth GA) bound to two sugars. Generally speaking, most raw sources of the licorice root tends to be about 1.5% glycyrrhizin by weight and, when eaten, you can digest it and get GA.

Beyond GA we also have glabridin (about 0.1% total weight) and liquiritigenin (about 3% total weight), two other molecules that explain the benefits of licorice.

Glabridin is notable since, due to problems with GA that we will get into, many supplements that do not have GA tend to focus on glabridin as the “cool guy” of licorice. It’s a relatively potent antioxidant and underlies many non-hormonal health benefits.

Liquiritigenin is pretty cool as well since the molecule it provides to the body, liquirtin, is only found in licorice and alfalfa. Also a pretty powerful antioxidant and, unlike the other “flavonoids” that you see in supplements, liquiritigenin is actually decently absorbed.

But really, the plant itself has a TON of unique molecules in it and at any point new discoveries could be linked to any of them, sort of like astragalus; I recommend giving the Examine page a general overview at your leisure.

If you want some mind candy to tickle your intellectual fancy then licorice root will more than suffice; it’s nice, when rhymed thrice.

Ultimately, a large part of licorice root is made up of a variety of bioactive compounds. Rather than being an inert candy it seems the opposite, a potential hot pocket of biological activity.

What Are The Benefits of Licorice Root?

Naturally we’re going to go over the human studies on this topic but, afterwards, humor me a bit and let me ramble on some super cool animal evidence.

Licorice Root and Antioxidant Effects

This is mostly due to the glabridin, but might just be because that’s the patented antioxidant in licorice root (patents get the studies, after all) but licorice root seems to have antioxidant potential.

At least two studies, one non-blinded and another double blind, report that supplementation seems to reduce oxidized lipoproteins in the blood. Oxidized lipoproteins, mind you, are involved in the pathology of atherosclerosis (clogged arteries), so this can be seen as heart healthy.

Licorice Root and Fat Burning

Licorice root has indeed dabbled in the realm of fat burning, related to the GA component.

Mechanistically it seems to have a few properties. It could promote mitochondrial uncoupling (this ancient study claims it’s similar in potency to 2,4-DNP and I call B.S.) and may synergistically enhance beta-adrenergic signaling (like ephedrine).

It’s due to the above properties that GA has been used, topically, for reducing subcutaneous fat (the jiggly kind sometimes called belly fat).

The flavonoids could also play a role, being able to stave off diet-induced obesity in both mice and rats. At least one study investigating the effects of 300 mg licorice oil (3% glabridin) showed a potential slight benefit during periods of overfeeding but not much more.

600 mg of the 3% glabridin supplement, however, may increase fat oxidation and oxygen consumption during light exercise but not rest. Both this and the aforementioned are minor effects, but demonstrable effects nonetheless.

That seems to be the only evidence at this point though, just three human trials that were all relatively short and didn’t showed anything remarkably potent. Might be a step in the right direction for a fat burning pre-workout though?

Licorice root has a bit of evidence to support the notion that it can help with fat burning, particularly when taken before a workout, but the evidence is not overly convincing.

Licorice Root and Oral Health

Licorice root, in part due to the antioxidant effects and in part due to taste, has been investigated for whether or not it can assist with oral health.

Can flavored toothpaste and candies prevent cavities?

To start with, licorice root seems to be useful in treating canker sores (aphthous ulcers) in the mouth when compared to placebo. This may also apply to licorice when used in patches and may be the only benefit of licorice on dental health, since the one study that used it in toothpaste didn’t find a significant result.

Licorice root seems to have the ability to reduce canker sores in the mouth but that may be the extent of its dental benefits.

Licorice Root’s Rapidfire Cool Experiments

I mentioned how licorice root just had such delicious data on it that may not be at the human level of investigation, right? Well, let’s just shoot it off here:

1. Isoliquiritigenin, another molecule found in licorice root, can reduce the ability of cocaine to release dopamine and, when liquiritigenin is given to rats at 5 mg/kg orally (0.8 mg/kg estimated human equivalent) it can halve the addictive potential of cocaine.
2. Licorice root is claimed to be sedative, being used in suanzaorentang (TCM for insomnia). Why though? Who knows, maybe due to acting at the benzodiazepine binding site (i.e. where and how benzo drugs work) but oral licorice root extract seems to work as well as diazepam in at least one rat study.
3. According to this review study, licorice root is one of the top five most promising kinds of TCM for senile dementia.
4. At least one mouse study showing improvements in memory of healthy mice with eating licorice root, estimated to be just about 5 grams of the dry plant weight.

God, I’m like a kid in a candy store and this is quite literally a candy I’m looking at. So many cool things associated with licorice root.

Licorice, in my not-so-humble-at-the-moment opinion, has a large degree of untapped potential that future human studies could investigate. Not just for health and wellness but also egotistical potential like fat burning.

Does Licorice Root Have Any Side Effects?

Yup, licorice root has side-effects. They’re pretty severe to boot, but avoidable.

The molecule, glycyrrhizin, which provides GA to the body, is known to inhibit an enzyme known as 11β-HSD, more potently in those with essential hypertension, and secondary to this will increase the ratio of cortisol to cortisone.

Or in short, make your body’s cortisol more potent.

GA can do this because the enzyme mentioned directly controls the conversion of the former into the latter and, when fed to both humans and research animals, increases cortisol and cortisol-like effects over the body pretty reliably.

(Perhaps this is why licorice root was used historically for “respiratory diseases” since they didn’t have corticosteroids in inhalers back then?)

Then, for more salt in the wound, secondary (not directly) due to inhibition of another enzyme (SULT2A1) from GA is thought to redirect steroid synthesis towards the cortisol family… and away from other steroid hormones… like androgens… which are reduced with GA in women and men.

While moderate intake of licorice root as a food product, 100 grams of licorice providing 150 mg GA, may be too low to influence hormones the threat is still there when GA gets up to 275 to 500 mg range. At least in the aforementioned study the decrease was noted to be 26% after one week although, admittedly, it’s pretty variable from one study to the next.

Licorice root has, due to the glycyrrhetinic acid content, the potential to both increase cortisol activity while simultaneously decreasing testosterone levels. The other components of licorice root do not appear to have this property.

That being said… cortisol isn’t totally bad.

Could some people benefit from the above actions?

What Are The Benefits of Licorice Increasing Cortisol?

There aren’t many, and I can’t say any of the following is actionable per se, but this article has quite a bit of mind candy anyways so let’s continue that theme.

Licorice Root and Fatigue (In the Morning)

This benefit is mostly theoretical, as no studies have investigated it directly yet, but cortisol is known to be a hormone that causes you to wake up in the morning.

Cortisol, normally low at night, increases progressively during sleep until it reaches a point where it can rouse you from slumber. Thereafter it helps provide a bit of energy for the short term while it gets reduced, letting calories from food and adrenaline take over during the waking hours.

This is a major reason why chronic stress can disrupt sleep since chronic stress disrupts the rhythm of cortisol and tells it to be up 24/7.

However, there may be some people who have suboptimal levels of cortisol in the morning which can cause fatigue. It’s likely not the major issue (Occam’s razor prefers “bad sleep” as an explanation) but it is possible that licorice could be a useful morning boost.

Licorice Root and Polycystic Ovarian Syndrome (PCOS)

Now, licorice can reduce testosterone in high doses.

Is there a situation where testosterone is abnormally elevated and we want to reduce it?

Yup, polycystic ovarian syndrome (PCOS)!

Licorice has not been tested too much for this surprisingly. A study where usage of licorice alongside spironolactone mitigated some side-effects of the latter is the only human study. Other evidence is in rats where licorice seems to potentially have pro-fertility effects in an experimental model of PCOS.

Ultimately it’s just not as good or well researched as Myo-inositol that we talked about previously.

What Is the Effective Dosage of Licorice?

The most important bit of information is that the estimated dose of 150 mg GA can be seen as the “upper limit” of intake where the cortisol and testosterone effects will not occur; the exception is in essential hypertension where this dose has effects.

This is about 100 grams of licorice a day, so some candy here and there is absolutely no problem (and I doubt Twizzler’s even have any real “licorice” in them anymore).

If you want the cortisol effects of GA, for whatever reason (perhaps to reduce inflammation or promote energy in the morning… both functions of cortisol) then 250 mg GA or more can be used.

If you want to experiment with the other compounds in licorice then you can either simply keep GA to a reasonably low intake or, alternatively, seek out “deglycyrrhizinated” licorice where the GA sources are removed.

Dosing of licorice just ends up deciding whether or not you want to deal with the glycyrrhetinic acid content and managing it. If you remain under 150 mg GA then you should be mostly fine.

The Bottom Line on Licorice

Licorice as a candy and licorice as a supplement should be considered as two separate beasts, unless you have a huge licorice habit or otherwise think eating the raw root is a tasty treat.

Healthy, versatile, and tons of unlocked potential; the benefits of licorice are numerous but heavily limited by the presence of GA that is one of the few compounds to be proven to reduce testosterone. Also increases cortisol, it’s a one-two punch right in the nads.

But assuming you can avoid that then it may be something to be on the lookout for, potentially even to seek its inclusion in a greens supplement (provided they can prove a low GA content).

What’s your take on licorice root supplements? Have anything else to share? Let me know in the comments below!