We’re all under stress, whether at home or at work or due to illness. So who wouldn’t like to find something that could boost resistance to the adverse effects of stress? A wide variety of herbal compounds are touted for their ability to help the body respond to or recover from physical or psychological stress, as well as for bolstering immunity and general well-being. One group of them is called adaptogens, a term coined in the early 1960s by Israel Brekhman, a Russian scientist.
The concept of adaptogens was based in part on a theory of stress called the “general adaptation syndrome,” proposed by an Austrian endocrinologist, Hans Selye. This basically holds that stress causes the body to go through three stages—preparing for fight or flight, adapting to the stress, and then exhaustion if the stress is long-lasting. Adaptogens are supposed to be a kind of general restorative tonic that counters the effects of stress, normalizes bodily functions, and helps the body heal itself.
Though not accepted by mainstream Western medicine, the concept that adaptogenic herbs can boost strength and vitality is integral to traditional Eastern medicine. As such, these herbs are often promoted as virtual cure-alls—“magic” or “miracle” remedies for everything from boosting mental attention and physical endurance to preventing a host of diseases. (Dr. Oz, in his typical pie-in-the-sky manner, titled one of them a “miracle pill for anti-aging.”) Even one supplement industry group, while praising adaptogens as “powerhouses,” warns that the marketing claims for adaptogens often are exaggerated, misrepresent the research, or are “pure fantasy.”
As with most herbs, there are few well-designed human studies on adaptogens. Moreover, the studies, many of them done in China or India, often use mixtures of herbs, so it’s impossible to know what is having an effect, if there is one.
One key problem is the variability of the herbs. Different species or varieties have different compounds and biological properties, and different parts of the plant (roots, leaves, stems) also contain varying chemicals. How the herbs are processed affects their biological activity as well. Moreover, it’s hard to study the many vague claims. How, for instance, do you measure increased “well-being” or “vitality”? Plus, it’s hard to know what you’re really getting in the bottles, since there is little meaningful regulation of dietary supplements.
That said, here are seven of the most popular adaptogens. Their potential adverse effects are grouped together at the end.
Ashwagandha (Withania somnifera)
Its name in Sanskrit means “like a horse,” referring to the pungent odor of the root. Also known as Indian ginseng (though not true ginseng) or Indian winter cherry,the root of this plant has long been used in Ayurveda, India’s traditional medicine and is considered to be the best adaptogen by many practitioners. Lab and animal studies show that ashwagandha has anti-inflammatory and neuroprotective properties, helps control blood sugar, reduces cancer growth, and boosts aspects of the immune system. Withaferin A, a steroid chemical, is considered the active compound responsible for ashwagandha’s anti-inflammatory properties and anticancer potential.
As far as clinical trials, a small study in BioMed Research International in 2015found that women (ages 21 to 50) who took ashwagandha for eight weeks had improvements in sexual health, including orgasm and arousal, compared to those taking a placebo.
In another small study, in the Journal of the International Society of Sports Nutrition in 2015, men (ages 18 to 50) who took ashwagandha or a placebo while participating in strength-training program. After eight weeks, those taking the herb had a significant increase in blood testosterone levels and muscle strength as well as a reduction in body fat and exercise-induced muscle damage that occurs after strength training compared with the placebo.
Astragalus (Astragalus membranaceus)
Traditional Chinese medicine has used this herb in the legume family for over 2,000 years, often combined with other herbs, to stimulate immunity, treat infections and fatigue, and as a general restorative. Typically used is the plant’s root, which is available in capsules, liquid extracts, powders, and teas. Lab and animal studies show that compounds in astragalus have anti-inflammatory, antioxidant, immune-boosting, and cardioprotective properties. While some small clinical trials suggest that astragalus has benefits—such as improving kidney function, improving allergy symptoms, reducing adverse effects from chemotherapy drugs, and countering fatigue in athletes—they have almost all been small and poorly designed. But other studies have failed to find benefits. For instance, an astragalus-based herbal formula didn’t extend the life of people with advanced lung cancer, according to a small NIH-sponsored study in 2009.
In 2014, a Cochrane Collaboration review of studies on the effect of astragalus on chronic kidney disease found that the herb held promise for improving kidney function but that the studies were mostly of poor quality. In 2016, another Cochrane review looked at studies on whether astragalus can prevent acute respiratory tract infections in children. After excluding most studies because of methodological problems, the researchers found insufficient evidence to support the claim.
In a study in Biomedical Materials and Engineering in 2015, researchersexamined the effect of astragalus in people with chronic obstructive pulmonary disease (COPD), a condition that involves immune dysfunction. They found that pro-inflammatory proteins declined while cells involved with immune activation rose, as did pulmonary function, during the 14 days after treatment. Longer-term effects are unknown.
Eleuthero (Eleutherococcus senticosus)
This small shrub from northern Asia, though not technically ginseng, is referred to as Siberian ginseng because it has comparable properties. Used as a traditional remedy in parts of Asia for centuries, this herb contains compounds called eleutherosides, which have neuroprotective and immune-boosting effects in lab and animal studies. They also help lower blood sugar in animals with an insulin deficiency.
However, there’s little clinical evidence that eleuthero can treat medical conditions in humans. A small French study in the Journal of International Medical Research in 2015 looked at people who suffering from job-related stress who took a formula containing eleuthero or a placebo for 12 weeks. The eleuthero group had greater improvements in sleep, fatigue, depression, and other stress-related parameters than the placebo group.
Ginseng (Panax ginseng or Panax quinquefolius)
Ginseng has been used as a cure-all since ancient times; the botanical name, Panax, means “all healing” in Greek. Common types include Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius). Proponents claim it can prevent or treat everything from colds, diabetes, digestive problems, and menopause symptoms to poor circulation, asthma, memory problems, erectile dysfunction, and even HIV infection and cancer.
Ginseng is one of the most researched herbs. Its active compounds include more than 40 ginsenosides, which have anti-inflammatory, antioxidant, anti-cancer and immune-modulating properties in lab research. They may also relax blood vessels (which may help lower blood pressure), help protect the nervous system, affect hormones and improve blood sugar, among other effects.
Small studies have suggested that ginseng can help control blood sugar, possibly by increasing insulin production, among other mechanisms. Others show that it increases various immune markers or reduces the frequency or severity of colds. In 2010 the Cochrane Collaboration concluded that there is “no convincing evidence of a cognitive enhancing effect of Panax ginseng” in either healthy people or those with memory problems or dementia. There’s no convincing evidence ginseng can treat or prevent fatigue, high blood pressure, cancer or any other condition it’s also touted for.
Holy basil (Ocimum sanctum)
Related to the sweet basil (Ocimum basilicum) used in cooking, this herb has long been used in China and India to treat everything from fever and colds to kidney and stomach diseases. It is also used in Thai cuisine (as in Pad Thai). Like other adaptogens, holy basil promoted as an immune booster.
In a small study from 2011 in the Journal of Ethnopharmacology, researchers found that when healthy people took the herb for four weeks, blood samples revealed that there was a statistically significant increase in immune proteins that are key in activating an immune response compared with the control group and compared with the baseline levels.
In a 2012 study in the Journal of Natural Remedies, a small number of subjects who had high blood pressure as well as elevated blood sugar, cholesterol, and triglyceride levels, took either holy basil or a placebo for three months. After that time, those on the herb had significant reductions in blood pressure, blood lipids, and blood sugar compared with their baseline levels and the control group.
Rhodiola (Rhodiola rosea)
Also called Arctic or rose root, rhodiola grows at high altitudes and in cold climes in Asia and Europe. It has been long used in Scandinavia, Russia, and other countries to treat an array of health problems, including headaches, mild to moderate depression, the flu,and anxiety. Animal and lab studies indicate it can have antioxidant(in part from its proanthocyanidins) and anti-cancer properties. The key active ingredient, rhodosin, inhibits an enzyme that breaks down neurotransmitters, suggesting it may act as an antidepressant.
In 2012, in a paper in BMC Complementary and Alternative Medicine, scientists reviewed 11 studies that examined Rhodiola for either mental or physical fatigue. They found that nearly all the studies had methodological problems and that the results were inconsistent.
In a 2015 study in Frontiers in Nutrition, marathonrunners took Rhodiola or a placebo during the month before their race, on the day of the race, and for a week afterwards. Lab tests of blood samples after the marathon showed that the herb promoted antiviral (but not antibacterial) activity. The researchers hypothesized that this suppression of viral replication might reduce the risk of upper respiratory infections that can occur after intense, prolonged exercise activities like a marathon, though the study did not look at this.
Schisandra (Schisandra chinensis)
Berries from this plant (called five-flavor fruit because they taste pungent, sweet, sour, salty, and bitter) have long been used in traditional Chinese medicine to boost strength, endurance, concentration and immunity.
Lab and animal studies suggest that compounds in the berries have anti-inflammatory, anti-cancer, metabolism-boosting, and liver-protective properties.
In a small Korean clinical trial in Nutrition Researchin 2015, obese women took schisandra or a placebo daily. After 12 weeks, there were no significant differences in terms of body fat, blood sugar, and gut microbiome.
Adverse effects of adaptogens
Many of these herbs (such as astragalus, rhodiola, and eleuthero) may increase bleeding, so they can be dangerous for people with bleeding disorders, those taking anti-clotting or other medications that increase bleeding risk, or those about to undergo surgery. Many also lower blood sugar levels, which could be risky for people people taking diabetes medication. Anyone with an immune or autoimmune disorder, hypertension, or other conditions or diseases should speak with their doctor if they are considering taking these herbs, as should people taking antidepressants, sedatives, or drugs that affect the immune system. Finally, women who are pregnant or breastfeeding should avoid these herbs, especially ashwagandha, schisandra, and holy basil.
Bottom line: It’s hard to evaluate adaptogens objectively. How they are typically studied and used in the West (as a single herb in a purified extract) is not how they are traditionally used (in its whole form and often combined with other herbs). Compounds in these herbs may someday prove to have benefits, particularly for the immune system or blood sugar control, but better, larger studies are needed, as well as standardized products, before we would recommend them. In the meantime, don’t believe claims that adaptogens will “restore” your body, “supercharge your cells,” or cure any disease.
Also see Herbal Supplements: Buyer Beware.