Huang Qi, which is the name for astragalus in Chinese, is one of the most popular herbs in traditional medicine.
Historically and even today, they use it for chronic kidney disease, diabetes, heart health, adjunctive therapy during cancer, and as an adaptogen (stress support) among other ailments. Often they combine it with their other 50 fundamental herbs like ginseng and ginkgo biloba, or their other prized plants like reishi mushrooms and ashwagandha. (1) (2)
To be clear, Traditional Chinese Medicine (TCM) uses for astragalus are unproven. Nor have any medical uses been approved in the US, UK, Canada, or any other western country. This plant should not be used to treat, cure, or prevent any disease. It’s intended as a dietary supplement only.
Perhaps that may change down the road though, if future research is able to conclusively prove health advantages in humans. In animal studies, there’s already a great deal of intriguing data, including anti-aging or longevity benefits by slowing the biological clock via the lengthening of telomeres.
What is astragalus?
Astragalus is the scientific name for a genus of around 3,000 different species of herbs and shrubs. Most often this word is in reference to Astragalus membranaceus (synonym: A. propinquus). That species is native to China, Kazakhstan, Mongolia, and the Siberian region. Medicinal uses of the plant’s root extract date back to the year 200 A.D.
The plant is actually in the same family as beans (Fabaceae) but you’re eating the root powder rather than the seeds, so no worries about gas and bloating!
Its Chinese name of Huang Qi is sometimes spelled Huang Chi. Other names for astragalus root include milk vetch and yellow leader, with the latter being the English translation of Huang Qi, which literally means “yellow senior” because it’s considered a leading herb in TCM. The astragalus Hindi name is katira, as it’s also used in the Ayurvedic medicine of India as an energy tonic.
What is astragalus good for? Perhaps a lot more than just Eastern practices. Western medicine has been actively researching it for a wide array of uses and most intriguing of all, anti-aging benefits.
You can think of telomeres as the end-caps on your chromosomes. They help protect your DNA from damage and mutations.
During youth, your telomeres are long. They get shorter as you age and in turn, the DNA between them is more susceptible to mutations. (3)
The enzyme telomerase has one job; restore telomeres by lengthening them.
The discovery of this enzyme was so important that the 2009 Nobel Prize was awarded to three scientists for finding “how chromosomes are protected by telomeres and the enzyme telomerase.”
Geron is a publicly-traded biotech company based out of Menlo Park, CA.
They are currently in development of first-in-class telomere-altering drugs through an exclusive collaboration and license agreement with Janssen Oncology (a Johnson & Johnson subsidiary).
Prior to their pharmaceutical pipeline with J&J, they were pioneering a compound to maintain or rebuild telomeres for anti-aging purposes. Known as TA-65, it’s a patented astragalus extract.
In animal studies, it was found to activate telomerase, the enzyme which slows down and may partially reverse age and lifestyle-related telomere shortening. (4) (5)
However, human trials for Geron’s telomerase activator never commenced.
The problem of “aging” from a business perspective is that technically, it’s not a disease. Therefore, it’s not something that would ever qualify for development into a prescription medication.
Perhaps that’s why Geron spun-off this invention and licensed it to a company called Telomerase Activation Sciences, who now sells it as a supplement.
Since it’s not a prescription, TA-65 is sold over-the-counter for use as a dietary supplement. It’s not cheap but if you can afford it, you can buy TA-65 on Amazon and elsewhere.
Back at Geron, their focus today is on other telomere-affecting compounds for use in medicine. By targeting the opposite effect – inhibiting or blocking the telomerase enzyme – they are now developing drugs for the rare bone marrow diseases myelofibrosis and myelodysplastic syndrome. Unlike with aging, for the affected cells in those diseases, shorter telomeres may actually be a good thing, because they want those cells to die off quickly. Likewise for cancer cells.
While the exact formulation of TA-65 is a trade secret, if you review Geron’s original patent filing for it, their claims would suggest that cycloastragenol in astragalus is the active or most important ingredient in their supplement.
The manufacturer had to submit an application to the UK Competent Authority in 2014 to sell it there and in that filing, they list cyloastragenol as being a 98% concentration (6):
Now here’s the interesting part, they also say:
“Cyloastragenol-TA65 is obtained from the Astragalus trojanus a perennial flowering shrub of the Fabaceae (or legume) family. Other species of Astragalus, most notably A. membranaceus, which also contain cycloastragenol are available in food supplements in the EU”
The reason why they’re extracting it from Astragalus trojanus versus Astragalus membranaceus species is not disclosed. How much cycloastragenol is in astragalus? According to other research, it’s in the range of 0.1% and 0.5% and samples of A. trojanus have tested as high as 4.8180 µg/mg (0.48%) which would place it among the best species for this particular compound. Perhaps that’s why they chose it as their source, but only our guess. (7)
Whatever the case, the filing with the UK authorities acknowledges that cycloastragenol is also in the A. membranaceus, which is what both traditional medicinal practices and virtually every other dietary supplement uses. Aside from TA-65 supplements, if you want to buy Astragalus trojanus, you can’t even find it for sale.
Cyloastragenol might be responsible for the telomere benefits, but it may not be the most important overall. To date there have been 126 different phytochemicals identified in the composition of astaragalus. The vast majority of studies focus on one in particular which is astragaloside IV.
But you can’t pit astragaloside IV vs. cycloastragenol, either. It’s possible there are synergistic effects which require other compounds to be present. Most of the 126 have little research on them. (8)
Astragalus membranaceus active ingredients or constituents may include the following, as each has only a concentration of around 1% or less:
- Astragalosides I-VII
- APS-I and APS-II
- Isoastragalosides 1, 2, and 3
- Cyclocephaloside 2
- HDTIC 1 and 2
- Nicotinic acid
The above list gets the most focus, but that’s not to say the others are unimportant.
The fact that there are lectins in astragalus may be of concern to some, but it shouldn’t be. Is it a nightshade? No, but it doesn’t have to be since all foods – every plant and animal tested to date – contains lectins. Secondly, the unique lectin in the astragalus herb is being studied for beneficial effects; anti-cancer activity. (9)
That and the apparent telomere-lengthening effect are only two of many topics being studied. The following uses and purported health benefits of astragalus are unproven, but they are what it’s used for in alternative medicine and/or what scientists are currently researching it for.
Astragalus root benefits
1. Supports immune system
In a double-blind study with 16 people, it was found that a 1.23g daily dosage of an astralagus tincture activated T-cells at a rate greater than echinacea. (10)
But that’s not to say they can’t be combined. It was reported that the echinacea along with astragalus and licorice together “had an additive effect” on the expression of the CD69, which is a well-known stimulatory receptor for activating natural killer (NK) cells. (11) (12)
2. Kidney protective effects
Extracorporeal shock wave lithotripsy (ESWL) uses sound waves to breakup kidney stones. In the process, it also causes kidney damage.
In an attempt to find out if astragalus kidney benefits were for real, out of 60 patients undergoing this procedure, half were randomly given the root extract beforehand.
After the ESWL, the placebo group was found to have far worse measures of plasma nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA), and serum tumor necrosis factor a (TNF-a). All of which are markers for kidney damage and stress. The differences between the two groups were statistically significant.
This is one of the most researched uses. You will find over 20 clinical trials in the PubMed database mentioning astragalus and kidney disease, along with 100+ papers on the topic.
There might be multiple mechanisms of action involved, but the most support is for the astragaloside IV. Research in 2017 concluded that it “protects against the progression of renal fibrosis by inhibiting inflammation via the TLR4/NF-кB signaling pathway.” (13)
3. Contains high amounts of antioxidants
The ORAC value of astragalus measures as being 17,773. This activity is coming from its kaempferol and quercetin – two potent antioxidants – among other compounds.
To put that number into perspective, here are the measurements for other popular herbs in Chinese medicine:
- Ginseng radix = 1,450
- Goji berries (fresh) = 3,290
- Ashwagandha = 8,487
- Reishi mushrooms = 9,244
- Elderberries = 14,697
- Ginger root (raw) = 14,840
- Ginkgo biloba = 35,850
Now the antioxidants in astragalus are high, but those ORAC values are based on 100g measurements. A typical dosage may equal 3 capsules and that would be around 1.5g. That equates to 250-300 ORAC units per dose (1.5% of 17,773). Considering that, it seems unlikely that the antioxidant activity is a primary cause for any health benefit.
Minerals and vitamins in astragalus will also be trivial since the serving size is so small.
4. May reduce cancer fatigue
According to the U.S. government’s National Center for Complementary and Integrative Health (NCCIH), one of the ways people use it is as “an adjunctive therapy for cancer.” (14)
What does that mean? They don’t provide an explanation, but it has been studied for helping with cancer-related fatigue in other countries.
At Mackay Memorial Hospital in Taiwan, researchers enrolled 91 patients in a study and a total of 58 completed both cycles. Along the way some withdrew, some were unable to be evaluated for fatigue, and sadly 6 died before completion.
Nearly 30% of the patients had breast cancer, with head and neck cancer being the second most common. Additionally, there were those with gynecological, gastrointestinal, respiratory, and male reproductive (presumably testicular cancer).
Roughly half of the patients were given astragalus injections while the others received a placebo injection of saline. The first cycle of these lasted 4 weeks and was done in a double-blind manner, while the second 4 week cycle was open-label (they knew what was getting).
Using the Brief Fatigue Inventory Taiwan (BFI-T) scoring methodology, this graph shows the the fatigue improvement between the two groups after the end of the first 4 weeks cycle:
PG2 is the astragalus group. The n’s you see represent the number of people in each category. The conclusion claimed their astragalus extract…
“…could be an effective and safe palliative treatment for relieving fatigue in advanced cancer patients.”
This was the first double-blind and placebo-controlled trial on that topic and it was published in 2012. (15)
Another was published prior, but since it involved a mix of herbs it’s irrelevant. (16)
As with the other purported health benefits, this anti-fatigue effect is still unproven. Neither astragalus supplements nor any other form should be taken during cancer unless the physician advises such usage.
5. Asthma relief remedy
In Traditional Chinese Medicine it’s frequently used for breathing difficulties, including those stemming from asthma. There are a couple dozen papers on this topic, including two human clinical trials.
Does astragalus work? A lot more research is needed to answer that question, but based on a study using a mouse model of “severe” induced asthma, it was discovered that the astragalus polysaccharides – such as astragalin, APS-I and APS-II – appeared to have a positive effect; “markedly suppresses mucus hypersecretion by decreasing the levels of mucin.” (18)
A rat study suggested it may work because it influences the gene expression of toll-like receptor 9 (TLR9) and T cell-associated interleukin (IL-4 and IL-13). In plain English, that may benefit rhinitis-asthma symptoms. (19)
As far as the human clinical trials, those both looked at astragalus extract asthma effects in children. Both took place in China and one has to be ignored altogether because it was a combination treatment involving astragalus and cordyceps, plus several other herbs. (20)
The other study is relevant because it involved 90 asthmatic children split into 3 groups:
- Group A = astragalus treatment
- Group B = hormone treatment (prescription medication)
- Group C = astragalus and hormone treatments combined
This was a long-term study that took place over one year, with multiple follow-up visits throughout.
How well did each treatment work? Based on peak expiratory flow rate and other markers, these were the total effectiveness rates:
- Group A = 66.7% improvement
- Group B = 73.3%
- Group C = 96.7%
The astragalus may not have worked as well as the hormones, but that’s still an impressive improvement for a herbal remedy! When both were combined, the results were the best. (21)
Exciting news but remember it’s only one study done in China. This remedy remains unproven.
6. COPD immune function
Similar to asthma, it’s also being looked at for Chronic Obstructive Pulmonary Disease (COPD).
Using a mice model, where the disease was induced using cigarette smoke exposure, it too found that the plant’s polysaccharides seemed to suppress the inflammatory response. This has also been seen in rat models of chronic bronchitis. (22) (23)
At least 9 human studies involving a total of 660 COPD patients have been conducted using astragalus jade screen. The Chinese call that the “Yupingfeng” formula and it also contains Atractylodes rhizome (Bai Zhu) and Ledebouriella root (Fang Feng). Since other ingredients are used, these studies aren’t very relevant. (24)
Jade screen aside, there is at least one human study that used only astragalus for COPD treatment. Or as the English translation reads, milkvetch root. Here’s how it worked:
- 73 patients completed it, 38 of which received astragalus and 35 did not.
- Average age of 73 and 74 for each group, respectively.
- Both groups received conventional clinical therapies during the trial, too.
- Blood serum levels of immune system markers were measured on day 1, 7, and 14 of treatment for both groups.
Among the immunocytes measured, the milkvetch group did better with all of them. Below are charts of four parameters.
As you see, the improvements for the herbal (experimental) group exceeded those seen in the control group. (25)
7. Smoking cessation aid
You will come across numerous herbal remedies claiming it can help you stop smoking, but most reasons cited are nonsense.
For example, one website claims that its antioxidants “…works by minimizing the oxidative damage caused by nicotine. This, in turn, allows the body to reduce it’s growing dependency on nicotine.”
Antioxidants have no direct bearing on substance addiction and even if they did, as shown above there won’t be much in the typical astragalus dose!
That being said, there is one South Korean study which suggests that astragalus tea benefits may include smoking cessation, but the reason why is unknown.
- 100 male smokers participated
- After screening 21 medicinal herbs, the researchers chose the 11 best based on antioxidant activity and used it to formulate an herbal tea. Out of those 11 it was reported that Eugenia aromaticum (clove spice) and Astragalus membranaceus Bunge variety had the best antioxidant activity.
- For 4 weeks, smoking withdrawal symptoms and urine samples were monitored.
For those drinking the tea it was discovered the cotinine level in their urine – which is a metabolite of nicotine – was much greater during the first 2 weeks versus the placebo group. This might suggest the body is ridding itself of the nicotine buildup faster.
The tea group experienced fewer cigarette withdrawal symptoms and at the end of the 4 weeks, 38% of them on astragalus quit smoking, while only 12% quit in the placebo group.
Of course the problem with this study is that other herbs were included in the tea so it’s unknown as to what benefit, if any, came from this root. (17)
8. Seasonal allergy relief
Many of the same effects seen in the asthma and COPD studies appear to be responsible for the reported astragalus allergy benefits.
One of those is the astragaloside IV and its apparent ability to reduce lung inflammation “by modulating the key master switches GATA-3 and T-bet.” (26)
Not China, but actually over in Croatia there was a human study done at a hospital of patients with allergic rhinitis.
In a double-blinded and placebo-controlled manner, 48 patients with moderate to severe symptoms were monitored for 6 weeks. Those in the treatment group were given an herbal and mineral complex whose primary ingredient was Astragalus membranaceus.
“…the analysis of changes from baseline inside the groups for TSS [symptom score], QoL [quality of life], and 4 main symptoms of SAR [seasonal allergic rhinitis] were strikingly in favor of the active treatment.”
That “active treatment” was the herbal treatment. In particular, they called out those with weed pollen allergies as having “significantly improved” symptoms. (27)
9. Arthritis and joint pain relief
Doing research on this topic is particular challenging because there is also the astragalus bone. More commonly known as the talus bone, it’s in your ankle joint.
Of course, you want to know about the dried astragalus plant and how it relates to orthopedic pain. There are no human trials, but several papers and lab studies.
In a study involving rats, injections were used to inflict arthritis-like effects of cartilage damage. Then, an oral dosage of 100 mg of the herb (per kg of body weight) was given to them on a daily basis.
The result? Reduced swelling and protection against cartilage destruction. (28)
Another study with mice used the isolated astragalus polysaccharides and had similar results. (29)
So what’s causing astragalus root and arthritis to have this interaction? Using living human cells in a Petri dish, Korean scientists discovered that formononetin, a phytoestrogen in the plant, was responsible for suppressing the pro-inflammatory cytokine production in their osteoarthritis cell model. (30)
Astragalus for dogs? Speaking of bones, Chinese researchers found that the polysaceharides helped with canine periodontal regeneration. Out of the 10 dogs used, those treated with the root had the highest tissue formation in which new bone was grown scaffolds. (31)
10. Acts as an adaptogen
When a supplement is mentioned on The Dr. Oz Show, you already know how shady marketers try to milk that. Which is why we are surprised no one seems to bring up astragalus and Dr. Oz.
A few years back, he talked about it in his “5-Day Energy Supercharge Program.” It’s listed as the supplement for the very first day. (32)
Then in an expanded piece on Dr. Oz’s website, they say the herb is “used as an adaptogen, which is meant to increase general resistance to stress and disease, and normalize.” (33)
Dr. Mehmet Oz isn’t the only MD talking about it. Dr. Weil has spoken of its adaptogenic qualities. Even the generic astragalus WebMD entry describes it in ways that sounds like one, saying it “appears to work by stimulating the immune system.”
Now to be clear, not Dr. Oz, nor Dr. Weil or WebMD are claiming those benefits. Rather, they are all just reporting what others use astragalus for and what they say about it. But what does the science say?
Is astragalus an adaptogen?
The word “adaptogen” is mainly relegated to alternative medicine. It’s not used by scientists.
However there is legit research about its immune-boosting and anti-stress benefits which could be interpreted as adaptogenic qualities.
We have already touched on the topic of purportedly boosting the immune system. There’s way too much about that to cover here.
As summarized in a 2017 scientific review of astragaloside IV, several decades of published studies mean the “the pharmacological effects are detailed, elucidated, and summarized” and among those they list immuno-regulation. (34)
Physical stress aside, when it comes to mental stress, there’s not much on the topic.
A study with mice found that the astragaloside IV reduced stress-inflicted anxiety in a manner similar to buspirone (Buspar). That’s a non-benzodiazepine anti-anxiety medicine, so it’s a different class than Xanax. Interesting, but there are no human trials on astragalus for stress and fatigue related to mental health. Nor is there anything for adrenal fatigue, which is not even a formally recognized medical condition.
11. Cancer research
The American Cancer Society’s Complementary and Alternative Cancer Methods Handbook makes mention of astragalus root extract, but not as a treatment for the disease. Rather, they just report how the Chinese use it as part of Fu Zhen therapy “to enhance the immune system.”
If you look for astragalus on Memorial Sloan Kettering’s website, under the “How It Works” section, the first sentence states: (35)
“Astragalus has immune-stimulating effects and may help to reduce side effects from chemotherapy, but it has not been shown to treat or prevent cancer.”
They also state that using it may interfere with immunosuppressant cancer medications, such as tacrolimus and cyclosporine.
The University of Maryland Medical Center lists this under its “Medicinal Uses and Interactions” section:
“Cancer. Preliminary studies suggest astragalus may have anti-tumor effects, specifically against melanoma and leukemia.”
The University of Maryland is touching on the fact that this herb has been researched for possibly having anti-cancer effects. (36)
There are over a hundred papers on PubMed about this topic, including:
In cultured non-small cell lung cancer cells, astragaloside IV appeared to suppress proliferation and enhance the effectiveness of gefitinib, which is a chemotherapy medication branded as Iressa. They claimed the effect was by “sensitizing” the cells to the medication, through the regulation of the SIRT6 pathway. That paper was published in 2017. (37)
That echoes research from the year prior, which found that the astragaloside IV reportedly boosted the effect of cisplatin (cancer medication) when both were used together on non-small cell lung cancer cells, which were also cultured. (38)
Another study from 2017 claimed that the isoflavone formononetin in the plant inhibited cultured bladder cancer cells through a different pathway (PTEN/Akt). (39)
When astragalus for prostate cancer cells in the lab was tested, it appeared to inhibit their growth through yet another pathway (ERK2). (40)
Liver cancer? When the astragalus polysaccharides were tested against those cells in the lab, it spurred apoptosis (controlled cell death) in a dose-dependent manner by influencing apoptosis-related genes, among other positive changes. (41)
Astralagus for colon cancer cells have been tested. The plants’ saponins, in combination with calpain enzyme inhibitors, reportedly “could exhibit a more pronounced pro-apoptotic effect.” (42)
This is just a small sampling of recent research published. To see more, search for Astragalus membranaceus and cancer on PubMed.gov.
These findings may sound exciting, but the truth is that there are hundreds of plants that demonstrate anti-cancer benefits in lab research. What works in a Petri dish rarely translates to whole living complex organisms (i.e. humans).
In 2002, there was a Chinese human study that used a dosage of astragalus for cancer. In addition to the patients’ standard chemotherapy, roughly half of them received a 20 ml dose (diluted in 250 ml of saline) which was administered by IV once daily for 21 days as one course. A total of 4 courses were given successively. (43)
“Astragalus injection supplemented with chemotherapy could inhibit the development of tumor, decrease the toxic-adverse effect of chemotherapy, elevate the immune function of organism and improve the quality of life in patients.”
The Chinese also published a human study in 2014 about astragalus and leukemia. They wanted to see if it influenced infection factors in children with acute lymphoblastic leukemia during remission induction chemotherapy. A total of 91 patients participated, 47 of which received the herbal injection.
That paper’s conclusion stated:
“Huangqi injection may reduce bone marrow suppression caused by chemotherapy drugs and increase neutrophil count during remission induction chemotherapy to reduce the incidence and duration of infection in children with ALL [acute lymphoblastic leukemia].”
In 2009, the U.S. government partially funded a study to see if an astragalus-based formula helped with lung cancer. It was done through the National Center for Complementary and Integrative Health (NCCIH). (14)
“…didn’t extend the life of patients with advanced lung cancer.”
In short, no astragalus benefits for cancer have been proven. Websites which claim it can be a “treatment” or “cure” are offering false hope and potentially dangerous advice. Astragalus should NOT be used for the treatment of this or any other disease.
Cancer is a deadly disease which is why it’s important to follow the advice of physicians and the treatments they advise.
It is true that some doctors recommend it for cancer-associated anorexia and quality of life (fatigue) during treatment. However that is NOT the same thing as a treatment for the actual tumors. And it’s not proven effective for those secondary side effects, either. (44) (45) (46)
12. Telomere lengthening
Back to the topic of telomeres, when Geron divested their TA-65 astragalus technology, at that time they had only published lab research showing this benefit.
Does astragalus root lengthen telomeres?
Finally in 2016, a randomized, double blind, and placebo controlled human study was published. 117 patients were monitored for 12 months. (47)
“The findings suggest that TA-65 can lengthen telomeres in a statistically and possibly clinically significant manner.”
It might be a telomerase activator supplement, but there are no studies demonstrating longevity or life extension from using TA-65 or generic astragalus root powder capsules.
The human papilloma virus (HPV) causes genital warts and is responsible for warts elsewhere on the body, too. A number of websites allege astragalus kills HPV but there’s literally no scientific evidence of that.
In fact, very little exists on the antiviral activity of astragalus.
When isolated, the plants’ polysaccharides have been found to help with hepatitis A in ducks. (48)
Almost 30 years ago, it was said to have a synergistic effect when combined with traditional treatments of herpes simplex virus type 2 and cytomegalovirus (CMV) infections. But there’s nothing to support that astragalus kills herpes on its own. Furtheremore, that was a lab study that didn’t involve animals or humans. (49)
The common cold virus (rhinovirus) and influenza virus which causes the flu has zero research.
Astragalus yeast infection remedies are others you may come across. There is no research about it for Candida albicans (candidiasis) or any other type of yeast/fungus.
Antibacterial benefits have been seen with some of the other 3,000 species in this plant family, such as Astragalus angulosus and Astragalus gombiformis. When it comes to the supplement Astragalus membranaceus, there is almost nothing to suggest it can effectively kill bacteria.
The closest thing out there is evidence that it may boost the host’s natural antibacterial defenses, such as what was seen with mice infected with E. coli. Despite what some blogs say, there’s nothing published about astragalus and kidney infections. (50) (51) (52)
Astragalus for Lyme disease and/or tick bites also has zero research behind it.
Side effects and interactions
Is astragalus safe? When used according to the dosage recommendations on most supplement bottles, it’s generally well tolerated. Unlike many other supplements, adverse reactions such as upset stomach, nausea, headache, diarrhea, and/or constipation are rarely reported.
Common side effects of astragalus root can include:
- Increased urination (diuretic)
- Interactions with immunosuppressant drugs
- Gas and bloating with higher amounts
- Lower blood sugar
- Lower blood pressure
- Possibly unsafe during pregnancy
- Unknown safety while breastfeeding
- Potential allergen
Keep in mind that many supplements combine this plant with other ingredients, such as Gaia Herbs with echinacea, Mediherb Complex, and Ki Immune Defence and Energy Formula.
If using complexes, consider all components – e.g. ginseng and astragalus side effects.
The list of astragalus drug interactions is long since it includes immunosuppressants, a category of drugs used for rheumatoid arthritis, Crohn’s disease, multiple sclerosis (MS), lupus, psoriasis, alopecia areata, and more. Those on medications for blood pressure, bleeding, and diabetes should also consider these potential interaction risks. (14)
As to what happens it too much is taken, that hasn’t been well documented in medical literature. PubMed produces zero results for astragalus overdose.
Is astragalus a blood thinner?
According to the University of Maryland Medical Center, it may increase the effect of anti-coagulants (blood thinners) which in turn, can increase the risk of bleeding and strong. For healthy individuals not using such medications, there is not enough data to determine if it has blood thinning effect or not. For that reason, it may be unsafe to take astragalus before surgery or if you are prone to bleeding. (53)
Does astragalus raise blood pressure?
Although unproven, data suggests it may actually have a lowering effect, based on benefits of pulmonary artery hypertension in rats and a human diabetic study where decreased systolic and diastolic was observed.
However, given the roots known interactions with drug metabolism and effects on the kidney, it may decrease the effectiveness of hypertension medications, which in turn, could raise blood pressure if you are on them.
In theory, thiazide diuretic drugs – which treat hypertension by helping the kidney eliminate sodium – seem particularly susceptible to an interaction. (54)
Warning for diabetics
In Traditional Chinese Medicine, recipes for astragalus tea, tinctures, and herbal complexes are used for type 1 and type 2 diabetes. These purported anti-diabetic benefits remain unproven in humans, but there is a fair amount of data to suggest it may improve insulin sensitivity and fasting blood glucose.
Normally those would be counted as health benefits of astragalus, but they could be considered the opposite – side effects – because the root may interfere with diabetic medications (e.g. causing too low of blood sugar when used in combination with insulin). (55)
The Chinese also use Huang Qi for diabetic nerve pain (neuropathy) but there are fewer studies on that and how it may affect other treatments for such. (56)
Is astragalus safe during pregnancy?
No. While human data is lacking, intravenous injections of pure astragaloside IV in pregnant rats and rabbits correlated with increased fetal deaths. Teratogenic effects (birth defects) at a greater rate were not observed, but there was a significant difference in the weight of the developing fetuses during and after treatment. (57)
Another rat study found that the root extract might help increase blood supply to the placenta in certain situations, such as during high blood pressure caused by pregnancy, which normally would be a benefit. However the effects on the developing babies wasn’t evaluated in this study, like the previous one did. (58)
Astragalus is bad for you during pregnancy and breastfeeding for the same reason. Human data for both scenarios is lacking and since there is research showing it’s unsafe in pregnant animals, it would be best to veer on the side of caution and avoid use while nursing your baby, too.
Effects on estrogen and testosterone
Estrogen dominance? Concerns about its phytoestrogen content have been raised on message boards, but when you look at the scientific data, it’s rather weak. Yes, it is one of many herbs used in Chinese medicine for menopausal symptoms and has shown estrogen-like activity in a lab study, but nothing compared to flaxseeds or soy. (59)
That being said, avoidance by estrogen positive breast cancer survivors seems like a good idea. The phytoestrogen in the plant, formononetin, has been found to promote those cell types (ERa-positive cells) in lab research. (60)
For men, there’s no hormonal reason to avoid it. Testosterone lowering effects have not been seen in studies.
Likelihood of allergies
As with all foods, an allergic reaction to astragalus is possible but to date there are no published case studies on this occurring. This suggests that it’s a rare allergy.
In the PubMed database, only one Chinese paper discusses allergy symptoms from skin-tests using so-called huang qi powder injections. There is no data on oral supplement uses and allergic reactions.
In fact, all of the other papers containing that word are about it being good for you if you have allergic rhinitis and asthma. (61)
Is astragalus safe for dogs and cats?
Uses for pets are becoming more prevalent. With the exception of dangers during pregnancy and breastfeeding, there isn’t reason to believe it’s more or less safe than human uses. Some canine supplements are even using it as an active ingredient, such as:
- VetriScience Laboratories chewables for kidney support
- HawaiiPharm Antioxidant Plus for veterinary use (alcohol-free liquid astragalus)
Remember that since no health benefits have been proven for it, you should not use it to treat, cure, or prevent any disease. It should be used as a dietary supplement only and under the directive of your doctor if you are on any medications and/or have health conditions it may interfere with.
The recommended dose of astragalus will vary based on the form it comes in. Pill forms (i.e. capsules and tablets) are more straightforward, since they should contain a measured amount.
When it comes to drinking an astragalus tincture, tea, or juice, the amount consumed is less predictable and can vary immensely based on how it’s formulated.
For that reason, the best way to take astragalus will be in a measured capsule form, according to the instructions on the label.
When standardized to 70% polysaccharides content, many supplement brands list dosages of 500 mg to 1,500 mg per day. That equates to 1-3 capsules but can vary based on manufacturer.
The astragalus root dosage for the raw powder is 1 to 2 teaspoons (2 to 4 grams) taken at a frequency of up to 3x daily. At least that’s according to the brand Jing Herbs.
How to take astragalus?
As a powder, dilute with water. Stir it into warm water to make a herbal tea. When to take? Whether it’s the tea or capsule form, preferably right before meals or with a snack.
Even though many of the compounds are water soluble, some are fat soluble. To boost bioavailability, it may help to take it with food that involves some fat.
Not much is needed though, as a splash of coconut milk in your tea or as a drink to accompany your capsules should be plenty sufficient.
What does astragalus root taste like? Earthy, bitter, and slightly sweet. It’s not the best tasting thing in the world but the good news is that its flavor is mild, unlike other roots such as turmeric and ginger. Therefore it’s not unpalatable to drink strong astragalus tea on its own. Adding lemon juice can help.
Of course with capsules, you won’t have to worry about taste being a problem.
If taking multiple dosages per day, it’s best to split them evenly. Since it’s caffeine-free and isn’t known to cause drowsiness or sleep problems, taking it in the morning, afternoon, and/or evening should all be suitable times.
Can astragalus be taken long term?
Practitioners of traditional medicine typically advise against using adaptogenic herbs for extended lengths of time. Instead, they often recommend cycling to a different herb or complex after a few months. Scientifically speaking, astragalus long term use has insufficient data to establish its safety. For that reason, taking it everyday for many months or year(s) may carry additional unknown risks.
Product reviews & where to buy
What is the best astragalus supplement? You have a plethora of options to choose from…
For capsules and tablets:
- Dragon Herbs
- Fusion Astra 8 Immune Tonic
- Gaia Herbs Supreme*
- Ki Immune Defence*
- Life Extension
- Nature’s Answer
- Nature’s Way
- Nature’s Sunshine
- NOW Foods
- Oriental Botanicals Astragalus 8*
- Paradise Herbs
- Piping Rock
- Quantum Health*
- Seven forests Astragalus 10+*
- TA 65 (98% cyloastragenol)
- Viridian (UK brand)
- Vitacost generic
- Vitamin Shoppe generic
- Gaia Herbs
- Herb Pharm
- Nature’s Answer
- Oregon’s Wild Harvest
- Planetary Herbals
- Zand Astragalus Formula*
- Jing Herbs
- Starwest Botanicals
- Sun Potion
For skin care:
- Donell Telomera Anti-Aging Moisturizer*
- Young Living Renewal Serum*
- Buddhas Teas
- Celebration Herbals
- Dragon Herbs Astragalus eeTee
- Ron Teeguarden’s Spring Dragon*
The options can be overwhelming, so which should you choose?
There are many fine brands on this list, the important things it to choose one with a standardized amount of the polysacchrides (70% is typical). That way you know it’s not diluted. You will be less likely to take too much or too little.
You may (or may not) care about fillers, such as magnesium stearate, so keep an eye out for any which concern you. If you’re vegan and want to avoid gelatin, choose a brand with Vcaps for sale. Very few brands are certified kosher.
We don’t like the complexes because most have a label that says “proprietary blend” so you don’t know how much of each ingredient you’re getting. There are a few exceptions though, like Quantum Health lysine, olive leaf, and astragalus (branded as Super Immune +) in which they disclose the breakdown.
If you need help narrowing them down, our “best” list includes the following:
For organic astragalus root powder, try Starwest Botanicals 1 lb bag on Amazon. You can use it to make tea, too.
There’s no such thing as astragalus essential oil, but the tiny vials of liquid extracts resemble an EO bottle. If you want USDA certified organic liquid, buy Herb Pharm’s tincture. Remember it’s not an essential oil.
As far as the two buzzworthy active ingredients – astragaloside IV and cycloastragenol – remember the dried root powder only has those in very low concentrations; 0.8-1.7% and 0.1-0.5%, respectively (see active ingredients section above). If you want to focus on dietary supplements with a higher amount of either, then consider…
For astragaloside IV:
Products marketed as fermented or activated astragalus root extract may or may not be better. They may be worse because some compounds in the plant would likely degrade during fermentation. Bioavailability studies are needed to accurately review and rate these.
For just a no-frills organic astragalus, try Oregon’s Wild Harvest made with non-GMO vegetarian capsules.
Finding where to buy astragalus at a physical store can be difficult. We checked our local Whole Foods and they only had Gaia Herbs Astragalus Supreme, which is a complex with schisandra berry and ligustrum berry. We saw liquid tincture for sale at an independent grocer, but that’s not something you’re likely to find at Walmart or GNC.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.