The roots of Pueraria mirifica are cherished in Thailand for their alleged anti-aging and antioxidant properties. People take this plant for menopausal complaints, cognitive effects, and heart and bone health. However, limited evidence supports most of its traditional uses. Read on to find out more about the purported benefits and side effects of Pueraria mirifica.
What is Pueraria mirifica?
Overview
Also known as White Kwao Krua, Pueraria mirifica is a medicinal plant that originates in Thailand. People in Thailand have thought that this herb has anti-aging properties for centuries [1].
Pueraria mirifica is a woody plant that climbs as it grows. The real interest is in the roots, which are large tubular structures that contain many starch granules and are white on the inside [1].
However, Pueraria mirifica supplements have not been approved by the FDA for medical use. Supplements generally lack solid clinical research. Regulations set manufacturing standards for them but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.
Components
The roots contain phytoestrogens, which are plant compounds that mimic the female hormone estrogen. At least 17 phytoestrogens have been identified, which can be categorized into isoflavonoids, coumestans, and chromenes. The most common phytoestrogen in Pueraria mirifica is miroestrol [1].
The exact phytoestrogen content of the plant depends on its location and variety [1].
The phytoestrogen content also depends on the age of the plant. Older plants have more consistent and substantial phytoestrogen content. One study determined plants that were 3 years old were best for use as supplements [1].
Also, plants harvested in the summer had a much higher phytoestrogen content than in the rainy and winter seasons [1].
In Pueraria mirifica herbs, phytoestrogens are found in the leaves, stems, and roots. However, the phytoestrogen content is much larger in the roots [1].
Mechanism of Action
Scientists hypothesize that the phytoestrogen content of Pueraria mirifica mimics the effects of the female sex hormone estrogen [1].
Purported Health Benefits of Pueraria mirifica
Remember to speak with a doctor before taking Pueraria mirifica supplements. Pueraria mirifica should never be used as a replacement for approved medical therapies.
Possibly Effective:
1) Alcoholism and Binge Drinking
In two small studies, heavy drinkers who took Pueraria mirifica extract for 1-4 weeks drank less beer when given an opportunity [2, 3].
In another trial, binge drinkers who took the extract about 2 hours before drinking had 37% fewer beers, compared to placebo [4].
However, evidence suggests that Pueraria mirifica does not appear to decrease alcohol craving in general or sobriety in chronic alcoholics [5].
Insufficient Evidence:
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of Pueraria mirifica for any of the below-listed uses.
2) Menopausal Symptoms
In a small clinical trial of 5 volunteers, an oral supplement of P. mirifica reduced symptoms of menopause. Patients received a 200 mg daily dose for 4 months, followed by 200 mg every 2 days. These patients showed decreases in menopausal symptoms, including [6]:
- Hot flashes
- Frustration
- Sleep disorders
- Skin dryness
- High blood cholesterol levels
- Absent Periods
- Irregular periods
In one study (DB-RCT) of 71 healthy postmenopausal women, the women received either a placebo or 20 mg, 30 mg, or 50 mg of Pueraria mirifica supplement. Pueraria mirifica was effective at decreasing vaginal dryness [7].
Another study (DB-RCT) of 37 premenopausal and postmenopausal women determined that 50 mg and 100 mg of Pueraria mirifica were effective at reducing hot flashes and night sweats [8, 9].
Despite these promising findings, large-scale clinical trials are needed to confirm the effectiveness and safety of this plant for menopausal symptoms.
3) Bone Health
Limited evidence supports the use of Pueraria mirifica for bone health in humans.
We identified only one clinical trial (DB-RCT) of 71 postmenopausal women. In this study, 24 weeks of P. mirifica supplements improved bone structure. The phytoestrogens in the plant are hypothesized to slow bone deterioration [10].
In rats, the ingestion of Pueraria mirifica with meals prevented osteoporosis, increased bone formation, and reduced bone loss and deterioration [11, 12].
Additional research is needed.
4) Heart Health
According to some theories, postmenopausal women have a decreased ability to process fats. This can lead to fat deposits in arteries and veins, which increase heart disease risk.
In a study (DB-RCT) of 19 postmenopausal women, oral ingestion of Pueraria mirifica powder improved heart function. After 2 months of treatment, the women had a better ability to processing fats and improved heart function [13].
In rabbits, P. mirifica improved heart function and reduced heart disease risk [14].
We can’t draw any conclusions from a single clinical study that had a very small sample size. Further studies are needed.
Lacking Evidence:
No clinical evidence supports the use of Pueraria mirifica for any of the conditions listed in this section.
Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
5) Antioxidant Activity
Pueraria mirifica has weak antioxidant activity compared to other natural substances. However, P. mirifica antioxidants are able to increase the antioxidant activities of other compounds [15, 16].
In mice, miroestrol extracts from Pueraria mirifica improved antioxidant activity and had beneficial effects on the antioxidant activities in the liver. Pueraria mirifica may be beneficial as a replacement for hormone therapy to increase antioxidant activities [17].
The antioxidant effects of this herb have not been investigated in humans yet.
6) Effects on Brain Function
Though people traditionally take P. mirifica to improve memory, the effects of this plant on brain function in humans is completely unknown.
In rats, Pueraria mirifica supplementation increased the strength of signals sent between neurons. This means that it can increase the effectiveness and efficiency of brain function [18].
In another rat study, early treatment with P. mirifica decreased brain function impairment [19].
Cancer Research
In mice, pretreatment of a high dose of P. mirifica 4 weeks before treatment of a tumor decreased tumor development. Another rat study suggested that pretreatment of P. mirifica prevented the development of breast cancer [20].
In cells, purified phytoestrogens of Pueraria mirifica killed breast cancer cells and stopped them from spreading. However, phytoestrogens are toxic to cells. When given a carcinogen, high levels of this plant promoted breast cancer in rats [21, 22].
Proper safety trials on this plant are lacking. Its effects on cancer risk in humans are completely unknown.
Using Pueraria mirifica
Dosage
Pueraria mirifica is most commonly taken orally, usually in pill form. Traditionally, pills are made of finely ground root powder, but some commercial brands use the root extract [1].
Most studies on humans used 20 mg, 30 mg, or 50 mg per day doses. Further research is needed before a safe and effective dosage can be established [10, 9].
Side Effects
Human studies didn’t report toxic effects. However, proper safety data are lacking. Animal studies raise concern, suggesting that P. mirifica has a potential for harm [10, 9].
In mice, P. mirifica did not have toxic effects when the supplement was given to them in a powder form. When treated with a proportional dose to ones taken by humans, no abnormalities were found. But, when the dose was substantially increased, they found abnormalities in the blood [23].
Another mouse study found that high doses of P. mirifica can lead to decreased fertility, reproductive disorders, and the development of endometrial and breast cancer [24, 25].
In male and female mice, Pueraria mirifica may negatively affect reproduction and mating efficiency [25, 26].
Limitations and Caveats
Few human clinical trials have been conducted. The efficacy and long-term safety of Pueraria mirifica are unknown.
User Experiences
One user said she had a quick decrease in her menopausal symptoms.
Many users have claimed that Pueraria mirifica has enlarged their breasts.
One user said that after taking Pueraria mirifica they began to shake and felt weak as if they needed to eat something.
Another user said that after taking a Pueraria mirifica supplement, they felt weak and their heart hurt.
The opinions expressed in this section are solely those of the users who may or may not have medical or scientific training. Their reviews do not represent the opinions of SelfHacked. SelfHacked 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 from your doctor or another qualified healthcare provider because of something you have read on SelfHacked. We understand that reading individual, real-life experiences can be a helpful resource, but it is never a substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider.
Takeaway
Pueraria mirifica is a plant that grows in Thailand, where its roots are used in traditional medicine.
Despite some recent scientific interest, the potential health benefits and risks of this plant are still largely unknown.
According to a couple of trials, Pueraria mirifica extract might reduce the amount of alcohol people drink, especially in heavy drinkers and binge drinkers.
Scientists discovered that it contains many phytoestrogens, plant compounds that mimic estrogen in the body. Some evidence suggests Pueraria mirifica may improve menopausal symptoms, but further research is needed.
Human safety data on Pueraria mirifica are lacking, while animal experiments point to potentially serious side effects. Caution is advised.
