Even if you have never heard of it before, chances are you drank it. Glucuronolactone is a naturally-occurring substance and a lesser-known ingredient in energy drinks like Red Bull. It is also added to pre-workout supplements touted to increase physical performance, stamina, endurance, and detox. Find out if the popular claims about its benefits are valid and learn the potential dangers.
Glucuronolactone is a normal product of glucose breakdown in the liver. All connective tissues contain it, as well as many plant gums. The amounts found in food and those produced in the body, though, are negligible compared to the dosage in energy drinks and supplements .
Glucuronolactone is an ingredient in certain energy and sports drinks, such as Red Bull. As a supplement, it’s available in the powder/capsule form.
It is advertised as a supplement to enhance athletic performance, detoxify the liver, and reduce mental fatigue. However, clinical research about the specific effects of this compound is scant.
- Naturally occurring substance
- No reported side effects and toxicity
- Might have heart- and liver-protecting benefits
- May improve cholesterol levels
- Might aid in cancer prevention
- Combined with potentially harmful ingredients into energy drinks
- Lack of clinical trials
- Very few animal studies
- Animal studies only examined its breakdown products
Glucuronolactone converts to glucuronic acid in the body. This conversion occurs back and forth; there are equal amounts of each molecule in the body .
Glucuronic acid is involved in detox and the breakdown of glucose, as part of a specific pathway crucial for creating fatty acids, amino acids, and DNA components (known as the Pentose Phosphate Pathway) .
Upon glucuronolactone ingestion, glucuronic acid levels (in both blood and urine) will rapidly increase .
Glucuronic acid plays a key role in a detox pathway known as glucuronidation. It binds to chemical and environmental toxins, pharmaceutical drugs, and cancer-causing molecules. By joining with glucuronic acid, these toxins become [5, 6, 7]:
- More soluble
- Transported faster in the body
- Less toxic
- Eliminated through urine or feces
Another product of glucuronolactone breakdown is called D-glucaro-1,4-lactone. About 25% of glucuronolactone is quickly converted to it. This compound is a potent inhibitor of beta-glucuronidase, an enzyme dominantly produced by your gut bacteria. Various tissues can also make it in lower amounts (the liver, spleen, kidney, gut, endocrine glands and sexual organs) [1, 8+].
Gut bacteria that make beta-glucuronidase can break down complex carbohydrates. However, this enzyme reverses the glucuronidation process, which slows down detox. Its levels rise with exposure to chemical and environmental pollutants, such as tobacco smoke and heavy metals [9, 10].
High levels of beta-glucuronidase may point to :
- Liver inflammation and cirrhosis
- Liver inflammation
- Cancers: brain, colon, pancreatic, breast and prostate
No valid clinical evidence supports the use of glucuronolactone for any of the conditions in this section. Below is a summary of up-to-date animal studies, cell-based research, or low-quality clinical trials which should spark further investigation. However, you shouldn’t interpret them as supportive of any health benefit.
The effects of glucuronolactone on exercise performance and endurance have been studied in humans, but only as an ingredient in functional energy drinks.
Taking a pre-workout energy supplement (mix of caffeine, taurine, glucuronolactone, beta-alanine, creatine, and amino acids) 10 minutes before resistance exercises significantly increased workout performance in eight resistance-trained men .
In a clinical trial of 12 trained cyclists, consumption of Red Bull energy drink 40 minutes prior to exercise increased endurance and overall physical performance .
That said, energy drinks contain numerous ingredients aside from glucuronolactone, including caffeine, taurine, glucose, and B-vitamins. Therefore, the observed benefits cannot be attributed to glucuronolactone alone.
In a rat study, high doses of glucuronolactone enhanced physical performance and increased stamina given shortly before swimming exercises .
In a study of 36 participants, drinking Red Bull (composed of sugar, taurine, glucuronolactone, and caffeine) led to significant improvements in attention, concentration, and memory .
Drinking Red Bull improved driving quality, reduced variation in speed, and lowered mental strain from prolonged driving in 24 healthy volunteers .
In an observational study of 10 graduate students, drinking Red Bull led to faster motor reaction time, improved attention and decision making when compared to the control group .
Once again, Red Bull contains caffeine and other active ingredients that likely contributed to these results. In the lack of clinical research, we can’t estimate the nootropic effects of pure glucuronolactone.
No clinical evidence supports the use of glucuronolactone for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based studies; they should guide further investigational efforts but should not be interpreted as supportive of any health benefit.
In a study on human plasma, a product of glucuronolactone breakdown (D-glucaro 1,4-lactone) decreased damage to the blood proteins caused by free radicals. It reduced the excessive clumping of platelets that can lead to heart disease and stroke. This effect is amplified in combination with the antioxidant resveratrol, found in red wine [18, 19, 20].
Glucuronolactone might protect the liver by enhancing the glucuronidation detoxification pathway.
In rats with liver disease, D-glucuronolactone lowered liver inflammation (IL-6, NF-κB) and tissue injury markers. In addition, it increased antioxidant liver enzyme activity (SOD, glutathione, and glutathione peroxidase) .
Supplementation with a glucuronolactone breakdown product (D-glucaro 1,4-lactone) inhibited breast tumor growth in rats .
In rats with liver cancer, the same compound increased survival rates from 45% to 70%. It also reduced the levels of a cancer marker, alpha-fetoprotein .
Glucuronolactone plays a role in detoxifying the body from cancer-promoting chemicals, hormones, and pollutants. However, there’s no clinical evidence to support the use of supplemental glucuronolactone for cancer prevention.
The mentioned glucuronolactone breakdown product (D-glucaro 1,4-lactone) prevented high cholesterol levels in rats on a diet high in fat and cholesterol .
Keep in mind that the safety profile of glucuronolactone is relatively unknown, given the lack of well-designed clinical studies. The list of side effects below is not a definite one, and you should consult your doctor about other potential side effects, based on your health condition and possible drug or supplement interactions.
In six healthy people, 1 g of glucuronolactone did not cause negative health effects .
As mentioned previously, the effects of glucuronolactone in humans have otherwise only be evaluated using energy drinks. Any adverse effects mentioned below are due to energy drink consumption as a whole; they may or may not be related to glucuronolactone.
- Aggressive behavior: fighting, bullying
- Stress, anxiety, insomnia, depressive symptoms, suicidal ideation
- Negative cardiovascular impact: increase in blood pressure and heart rate
- Metabolic effects: obesity, increased risk of developing type 2 diabetes
- Dental decay
- Progression of chronic kidney disease
- Lack of sleep quality, fatigue/tiredness
- Stomach cramps/irritation
We can assume that a great deal of these effects could be due to high amounts of caffeine, sugars, and other components. The exact contribution of glucuronolactone is unknown.
There is no research on glucuronolactone interactions with prescribed medications or supplements.
Most glucuronolactone-containing drinks and supplements contain a wide array of stimulants and ergogenic ingredients. Consult your physician before consuming them, especially if you take prescription medication or have heart or mental health problems.
Glucuronolactone supplements have not been approved by the FDA for medical use. In general, regulatory bodies aren’t assuring the quality, safety, and efficacy of supplements. Speak with your doctor before supplementing.
Glucuronolactone is most widely available as an ingredient of various energy drinks. One 250 ml can of Red Bull contains about 600 mg glucuronolactone .
Wine is the richest natural source of this compound with concentrations around 20 mg/L .
Glucuronolactone is also available as a supplement, including the following formulations:
- Powder (in bulk or smaller boxes)
- Capsules (500 mg/capsule)
Since glucuronolactone is not approved by the FDA for any condition, there is no official dose. Users and supplement manufacturers have established unofficial doses based on trial and error. Discuss with your doctor if glucuronolactone may be useful as a complementary approach in your case and which dose you should take.
In an average diet, glucuronolactone intake through food sources is estimated to be very low (1.2 mg/day) .
Drinking one 250 ml can of a glucuronolactone-containing energy drink provides between 500 – 600 mg of glucuronolactone, depending on the brand. However, most manufacturers don’t specify the exact glucuronolactone content.
In supplement form, glucuronolactone is usually taken at 500 – 1,000 mg/day. Such dosage recommendations can’t be scientifically verified, due to the lack of clinical studies on glucuronolactone alone.
The opinions expressed in this section are solely from the users who may or may not have a medical background. SelfDecode does not endorse any specific product, service, or treatment. Do not consider user experiences as medical advice. Never delay or disregard seeking professional medical advice because of something you have read on SelfDecode.
Users taking glucuronolactone supplements generally report an increase in physical performance, stamina, improved mood, and reduced mental fatigue. However, it is important to mention that many users took this compound in combination with other performance-enhancing ingredients, such as caffeine, vitamin b12 and taurine.
Glucuronolactone is an essential component for detox. It activates pathways that bind and flush drugs, pollutants, and toxins. However, the benefits of supplementation lack clinical evidence.
While glucuronolactone shows some promise as a performance and energy enhancer, its clear benefits remain unknown. Most clinical studies used energy drinks, which contain many additional ingredients, some of which can have detrimental health effects.
People with anxiety and heart conditions should not consume energy drinks. To stay on the safe side, avoid glucuronolactone supplements as clinical information is lacking on its dosage and side effects.