Astragalus is an herb that has been used in traditional Chinese medicine for centuries.
It has many purported health benefits, including immune-boosting, anti-aging and anti-inflammatory effects.
Astragalus is believed to prolong life and used to treat a wide variety of ailments, such as fatigue, allergies and the common cold. It’s also used against heart disease, diabetes and other conditions.
This article reviews the many potential benefits of astragalus.
Though there are over 2,000 species of astragalus, only two are primarily used in supplements — Astragalus membranaceus and Astragalus mongholicus (2).
Specifically, the root of the plant is made into many different forms of supplements, including liquid extracts, capsules, powders and teas.
Astragalus is sometimes also given as an injection or by IV in a hospital setting.
For example, its active compounds may help strengthen the immune system and reduce inflammation (5).
Summary Astragalus is an herbal supplement that has been used for centuries in traditional Chinese medicine. It’s purported to enhance the immune system and reduce inflammation. It’s also used to help treat heart conditions, kidney disease and more.
Astragalus contains beneficial plant compounds that may enhance your immune system.
The primary role of your immune system is to protect your body against harmful invaders, including bacteria, germs and viruses that can cause illness (7).
While these studies are promising, more research is needed to determine the effectiveness of astragalus for preventing and treating infections.
Summary Astragalus may help enhance your immune system to prevent and fight bacterial and viral infections, including the common cold.
Astragalus may help improve heart function in those with certain heart conditions.
It’s thought to widen your blood vessels and increase the amount of blood pumped from your heart (14).
In a clinical study, patients with heart failure were given 2.25 grams of astragalus twice daily for two weeks, along with conventional treatment. They experienced greater improvements in heart function compared to those receiving standard treatment alone (15).
In another study, patients with heart failure received 60 grams per day of astragalus by IV along with conventional treatment. They also had more significant improvements in symptoms than those receiving standard treatment alone (16).
However, other studies in patients with heart failure have failed to demonstrate any benefits for heart function (17).
Additionally, some studies suggest that astragalus may reduce symptoms of myocarditis, an inflammatory condition of the heart. Yet, findings are mixed (18).
Summary Though research findings are mixed, astragalus may help improve heart function in patients with heart failure and reduce symptoms of myocarditis.
Chemotherapy has many negative side effects. According to some studies, astragalus may help alleviate some of them.
Similarly, several other studies have demonstrated benefits of the herb for nausea and vomiting in individuals undergoing chemotherapy for colon cancer (20).
Additionally, one clinical study showed that 500 mg of astragalus by IV three times weekly may improve the extreme tiredness associated with chemotherapy. However, astragalus only appeared to be helpful during the first week of treatment (21).
Summary When given intravenously in a hospital setting, astragalus may help alleviate nausea and vomiting in those undergoing chemotherapy.
The active compounds in astragalus root may help lower blood sugar levels in individuals with type 2 diabetes.
Though more research is needed, studies in humans so far point to similar effects.
For example, studies have shown that taking 40–60 grams of astragalus per day has the potential to improve blood sugar levels after fasting and after meals in people with type 2 diabetes when taken daily for up to four months (27).
Summary Studies indicate that astragalus supplements may help control blood sugar levels in people with type 2 diabetes. However, more research is needed.
Astragalus may support kidney health by improving blood flow and laboratory markers of kidney function, such as measures of protein in the urine.
Proteinuria is a condition in which abnormal amounts of protein are found in urine, which is a sign that the kidneys may be damaged or not functioning normally (28).
It may also help prevent infections in people with reduced kidney function (30).
For example, 7.5–15 grams of astragalus taken daily for three to six months reduced the risk of infection by 38% in people with a kidney disorder called nephrotic syndrome. However, more studies are needed to confirm this effect (31).
Summary Some studies suggest that astragalus may help improve kidney function in those with kidney disease. It may also prevent infections in those with reduced kidney function.
There are many preliminary studies on astragalus that indicate the herb may have other potential benefits, including:
- Improved symptoms of chronic fatigue: Some evidence shows astragalus may help improve tiredness in people with chronic fatigue syndrome when combined with other herbal supplements (29, 32).
- Anticancer effects: In test-tube studies, astragalus has promoted apoptosis, or programmed cell death, in various types of cancer cells (33, 34, 35).
- Improved seasonal allergy symptoms: Though studies are limited, one clinical study found that 160 mg of astragalus twice daily may reduce sneezing and runny nose in individuals with seasonal allergies (36).
Summary Preliminary research has found that astragalus may be beneficial at reducing symptoms of chronic fatigue and seasonal allergies. Test-tube studies suggest that it may also have anticancer effects.
For most people, astragalus is well tolerated.
When given by IV, astragalus may have more serious side effects, such as irregular heartbeat. It should only be administered by IV or injection under medical supervision (17).
Though astragalus is safe for most people, the following people should avoid it:
- Pregnant and breastfeeding women: There’s currently not enough research to demonstrate that astragalus is safe while pregnant or breastfeeding.
- Individuals with autoimmune diseases: Astragalus may increase the activity of your immune system. Consider avoiding astragalus if you have an autoimmune disease, such as multiple sclerosis, lupus or rheumatoid arthritis (1).
- Individuals taking immunosuppressant drugs: Since astragalus may increase the activity of your immune system, it may decrease the effects of immunosuppressant drugs (2).
Astragalus may also have effects on blood sugar levels and blood pressure. Therefore, use this herb with caution if you have diabetes or issues with your blood pressure (2).
Summary Astragalus is generally well tolerated but should be avoided if you are pregnant or breastfeeding, have an autoimmune disease or are taking immunosuppressant drugs.
Astragalus root can be found in many different forms. Supplements are available as capsules and liquid extracts. The root may also be ground into a powder, which can be brewed into teas (2).
Decoctions are also popular. These are made by boiling the astragalus root to release its active compounds.
Though there’s no official consensus on the most effective form or dosage of astragalus, 9–30 grams per day is typical (38).
Additionally, research shows the following oral doses to be useful for specific conditions:
- Congestive heart failure: 2–7.5 grams of powdered astragalus twice daily for up to 30 days, along with conventional treatment (15).
- Blood sugar control: 40–60 grams of astragalus as a decoction for up to four months (27).
- Kidney disease: 7.5–15 grams of powdered astragalus twice daily for up to six months to reduce the risk of infections (31).
- Chronic fatigue syndrome: 30 grams of astragalus root made into a decoction with several other herbs (32).
- Seasonal allergies: Two 80-mg capsules of astragalus extract daily for six weeks (36).
Based on the research, oral doses of up to 60 grams per day for up to four months seem to be safe for most people. However, there are no studies to determine the safety of high doses in the long term.
Summary There’s no official consensus for recommended doses of astragalus. Dosages vary depending on the condition.
Astragalus may improve your immune system and symptoms of chronic fatigue and seasonal allergies.
It may also aid people with certain heart conditions, kidney disease and type 2 diabetes.
Though no dosage recommendation exists, up to 60 grams daily for up to four months appears to be safe for most people.
Always discuss the use of supplements with your healthcare provider first.