What Traditional Chinese Medicine is, and isn’t
Traditional Chinese Medicine (TCM) is a system of healing that developed in China over roughly two thousand years. It includes herbal medicine, acupuncture, dietary therapy, and movement practices like tai chi. Many of its herbs, including ginseng, astragalus, reishi, and cordyceps, are now sold in Western supplement aisles as single-ingredient capsules.
That shift matters, because it changes how the herbs are used. In TCM, a practitioner assesses a person’s overall “pattern” using concepts like qi (vital energy), yin and yang, and heat and cold, and then prescribes a formula that often combines 4 to 15 herbs, adjusted over time. Single herbs taken off the shelf for a Western-style goal (“energy,” “immunity”) are a modern, simplified use.
Two things can both be true:
- A long history of use tells you which plants people found worth studying and which doses they tolerated.
- A long history of use isn’t evidence that an herb works for a specific outcome, or that it’s safe with modern medications.
This guide covers what controlled research says about the TCM herbs you’re most likely to see as supplements.
Herbs with the most human research
Panax ginseng (ren shen)
Asian ginseng is probably the most studied TCM herb. Trials have looked at fatigue, cognitive performance, blood sugar, and quality of life, with results that are modest and inconsistent. Some trials in people with chronic fatigue or in healthy adults reported small improvements in energy or mental performance; others found no difference from placebo.
- Typical dose: 200-400 mg/day of a standardized extract, often taken in the morning because it can interfere with sleep
- Common side effects: insomnia, headache, digestive upset, and nervousness at higher doses
- Interactions: may reduce the effect of warfarin; may add to the effect of diabetes medications and lower blood sugar; caution with MAO inhibitors and stimulants
Note that American ginseng (Panax quinquefolius) and “Siberian ginseng” (eleuthero) are different plants with different research. See our ginseng page for details.
Ginger (sheng jiang)
Ginger is both a kitchen spice and a TCM herb, and it has some of the most consistent evidence of any herb in this list. Controlled trials support ginger for nausea, including pregnancy-related nausea and motion sickness, typically at about 1 g/day of ginger root split into doses. It’s generally well tolerated, though high doses can cause heartburn, and it may add to the effect of blood thinners.
Red yeast rice (hong qu)
Red yeast rice is rice fermented with a mold, used in Chinese cooking and medicine for centuries. It contains monacolin K, which is chemically identical to the prescription statin lovastatin. That’s why it can lower LDL cholesterol, and also why it carries statin-like risks, including muscle pain and, rarely, muscle and liver damage.
The amount of monacolin K varies enormously between products, and some batches have contained citrinin, a kidney toxin produced during fermentation. Anyone taking a statin shouldn’t add red yeast rice, and it isn’t appropriate during pregnancy. More on our red yeast rice page.
Herbs with preliminary or mixed evidence
Astragalus (huang qi)
Astragalus root is used in TCM to “tonify qi” and is marketed in the West for immune support. Most of the research is in cells and animals, where astragalus compounds affect immune cell activity. Human studies are few, often small, and frequently test astragalus as part of a multi-herb formula, which makes it hard to credit any single ingredient. The immune claims are plausible but unproven.
Because astragalus may stimulate immune activity, people taking immunosuppressants, including transplant recipients, should avoid it unless their care team approves. See our astragalus page.
Reishi (ling zhi)
Reishi mushroom has a large lab literature on polysaccharides and triterpenes, but controlled human trials are limited and results are mixed. There are rare case reports of liver injury, particularly with powdered products. Reishi may also have mild blood-thinning and blood-pressure-lowering effects, so it deserves caution alongside anticoagulants, blood pressure medications, and before surgery. See our reishi page.
Cordyceps (dong chong xia cao)
Wild cordyceps is a fungus that grows on caterpillar larvae and is extremely expensive, so almost all supplements are lab-cultivated strains. Small trials have tested cordyceps for exercise performance with mixed results, some showing slight improvements in oxygen use in older adults and others showing nothing.
Schisandra (wu wei zi)
Schisandra berry is classed as an adaptogen and is studied mostly in animals and small human trials on stress, fatigue, and liver enzymes. The more practical issue is that schisandra can affect drug-metabolizing enzymes in the liver. It has been shown to raise blood levels of some medications, including the transplant drug tacrolimus. If you take prescription drugs, check before using it. See our schisandra page.
Herbs to approach with real caution
Some TCM herbs have well-documented risks that are easy to miss when you buy online.
- Aristolochia species (guang fang ji and others): these contain aristolochic acid, which has caused kidney failure and urinary tract cancers. Serious harm has been linked to products where an Aristolochia species was substituted for a similar-sounding, safer herb. The FDA has warned against products that contain or may contain it.
- Ephedra (ma huang): the source of ephedrine. Ephedra-containing dietary supplements have been banned in the US since 2004 after reports of heart attacks, strokes, and deaths.
- Licorice root (gan cao): a very common formula ingredient. Its glycyrrhizin can raise blood pressure, lower potassium, and cause fluid retention with regular use. People with high blood pressure, heart or kidney disease, or who take diuretics or digoxin should avoid non-deglycyrrhizinated licorice.
- Dong quai (dang gui): often marketed for menstrual and menopausal symptoms, with little supporting trial evidence. It may increase bleeding risk with warfarin and isn’t recommended during pregnancy.
- Chinese skullcap (huang qin): has been linked to cases of liver injury, including in combination joint products.
The quality problem
The biggest practical risk with TCM products often isn’t the herb itself. Analyses of imported herbal products over the years have found:
- Heavy metals such as lead, arsenic, mercury, and cadmium
- Undeclared pharmaceuticals, including steroids, blood thinners, sildenafil, and weight-loss drugs, particularly in products marketed for sexual performance, weight loss, or joint pain
- Misidentified or substituted plants, which is how the aristolochic acid cases occurred
- Pesticide residues
- Endangered animal ingredients in some traditional remedies
To lower your risk:
- Choose single-herb extracts from brands that publish third-party testing for identity, heavy metals, and contaminants.
- Be wary of imported formulas with labels you can’t read, dramatic claims, or unusually fast results.
- Avoid products marketed for sexual enhancement or rapid weight loss, the categories where drug adulteration shows up most often.
- If you see a licensed TCM practitioner, ask where the herbs are sourced and whether they’re tested, and give your doctor the full formula ingredient list.
Pregnancy, surgery, and medications
Most TCM herbs lack pregnancy safety data, and some formulas have traditionally been used to stimulate menstruation. Avoid them during pregnancy, while nursing, or when trying to conceive unless a clinician who knows your history approves.
Several of these herbs, including ginseng, ginger in large amounts, reishi, and dong quai, may affect bleeding, so stop them before surgery following your surgeon’s instructions (commonly about two weeks ahead). And because formulas combine many herbs, interactions are harder to predict. Bring the actual product or the full ingredient list to your pharmacist.
For more on immune claims specifically, see our immune support roundup.
Bottom line
Traditional Chinese Medicine has pointed researchers toward some genuinely interesting plants. A few, including ginseng, ginger, and red yeast rice, have real if modest human evidence, and red yeast rice works because it contains what is effectively a statin. Others, like astragalus, reishi, cordyceps, and schisandra, rest mostly on lab work and small trials. The most important decisions are about safety: buy tested single-herb products, stay away from anything that could contain aristolochic acid or ephedra, and check interactions before adding any herb to a medication routine.
This article is for educational purposes only and is not medical advice. Consult a healthcare provider before starting any supplement, especially if you are pregnant, nursing, taking medication, or managing a health condition.