More on Adaptogens: Ashwagandha, Astragalus, and Holy Basil

Holy Basil leaf herb ingredient of Thai food.Last week I waded into the adaptogen theme, examining the many ins and not-so-many outs of American and Asian ginseng. It got me thinking—why not keep the ball rolling? The ginseng varieties I mentioned are only two among many adaptogens after all.

Let’s dive right in and take up three additional adaptogen choices—along with some additional suggestions for discerning the safest and most potent formulations. 

From Dirt to Dispensary: The Life Cycle of Your Adaptogen Sources

It’s probably fair to say that, as a nation, we’ve got a pretty poor connection with the food we eat. Primal eaters, other nutrition buffs, and some foodies aside, most Americans have no idea how the food they’re eating got on their plates, let alone what ingredients it actually contains.

Personally, I think it’s important to have at least a vague sense of our food’s origins. Wrapping your head around its life cycle, how it was grown, harvested, and distributed often goes a long way towards understanding whether it’s a good choice (e.g. healthy, sustainable) and which perhaps which brands or versions you should favor. The same applies to supplements—including adaptogens.


Ashwagandha (Withania somnifera) is a perennial shrub native to the drier areas of India and South Asia. Hailing from the same family as tomatoes, peppers, and other nightshades, ashwagandha is otherwise known as Indian ginseng (no actual relation), winter cherry, and poison gooseberry. This last, rather alarming, title seems to be a misconception, as research indicates no toxic effect from any part of the plant. That being said, it’s generally only the roots that are used in traditional medicine and modern supplements anyway.

In the wild, ashwagandha grows across much of Asia, with close members of the Withania family extending into the Middle East and Northern Africa. While certain other members of this family contain notable levels of therapeutic compounds, particularly the steroidal lactones withanolides, ashwagandha refers only to plants of the species Withania somnifera. Cultivation of ashwagandha has, unsurprisingly, spread across the globe with increasing popularity of adaptogens in general and ashwagandha in particular, and there are now plenty of farms within the U.S. that grow the stuff.

Around 180 days after germination, these itty bitty ashwagandha plants are dug up whole, and the roots chopped off and dried. Once dried, the roots are typically ground to make a therapeutic powder, or else cut into smaller pieces for other medicinal applications. These roots contains high concentrations of various beneficial compounds, including the alkaloids ashwagandhine, ashwaganidhine, and somniferine.

As a nifty bit of trivia, in Sanskrit, ashwagandha means something along the lines of “odor of the horse”, presumably owing to its rather pungent (sometimes nauseating) aroma which is somewhat reminiscent of a sweaty horse. The latin name for this herb, somnifera, translates to “sleep-inducer” which is fairly self-explanatory. So there you go: a sleeping pill that smells like a horse. (There’s more to it of course, but I’ll get to that in a minute.)


Astragalus is a perennial herb of similar proportions to ashwagandha, and is native to the northern and eastern regions of China. Also known as milk vetch and huang-qi, astragalus is one of over 2000 species in the genus. Of those 2000+, only two—astragalus mongholicus and astragalus membranaceous—are used medicinally. While the literature generally chops and changes between these two medical species, there tends to be more favoritism in the literature towards membranaceus, and it is this species that generally holds the coveted “astragalus” title in the adaptogenic world.

As with ashwagandha, it’s typically only the root that’s used for medicinal purposes. These roots are harvested from 4-year old plants, dried, and then sent forth into the world for various medicinal concoctions. These days, most of the astragalus supplements on the market are cultivated, but there are occasional products which offer wild-harvested varieties.

Holy Basil

To complete this particular trio of adaptogens, we have holy basil. The history of this fragrant herb is arguably even richer than that of the other two adaptogens, forming a pillar of Ayurvedic medicine and held as a sacred plant in both the Hindu and Christian religions. The name is very much earned, it would seem.

Holy basil (Ocimum tenuiflorum aka sanctum) also goes by the names of tulsi, tulasi, and even sacred basil. Likely native to tropical Asia, holy basil is now grown in most warmer regions of the world. The plant itself grows into an herbaceous shrub with hairy stems and greenish, purplish leaves. The best way to get hold of organic, high-potency holy basil is to grow it yourself. It’s not hard, provided you’ve got a long enough growing season. Otherwise, the majority of cultivated holy basil hails from Southeast Asia.

Unlike ashwagandha and astragalus, it’s the leaves of holy basil that are primarily used in therapeutic supplements and tinctures.

A Scientific Take on Adaptogens

It’s difficult to sit down and list off the many health benefits of adaptogens for a couple of reasons. The first is that there’s just so darn much research out there. Many of these herbs have received scientific attention for many decades, some even presenting over a century worth of documented research. The second reason is due to the very nature of these herbs. Their beauty lies in their generality: they work synergistically on the body to achieve their therapeutic goals, rather than on targeted areas. Listing off their individual beneficial attributes is, to a certain extent, redundant.

But I get that simply implying that all therapeutic boxes are ticked on account of the “kill all stress” approach of adaptogens doesn’t make for a great read. You want stats, and I’ll certainly endeavor to give you some.

Ashwagandha Research

There’s plenty of anecdotal evidence to suggest that ashwagandha is an effective herb for treating anything from sleep disorders to arthritis. In addition, traditional Chinese and Ayurvedic medicine place great faith in ashwagandha as an immune-booster, a stamina-enhancer, and a stress reliever. But is there any substance to the claims? Let’s find out.


After scrolling through the literature, I’d have no qualms about backing up ashwagandha’s anti-arthritic and anti-inflammatory claims to fame. There’s been no shortage of studies examining this anti-inflammatory effect in rats in mice, with an earlier study showing that 1 g/kg of ashwagandha suspended in acacia gum could bring inflammation back down to negligible levels in short order. A later study by the same authors examined the anti-inflammatory effect of different ashwagandha dosages, once again finding that 1 g/kg was the magic ratio. A third study in arthritic rats found that this same dosage was more effective than hydrocortisone in reducing paw swelling and degenerative changes brought on by the induced arthritis.

Whether on rats or people, ashwagandha seems to be in its element when it comes to reducing both chronic and acute inflammation. In a study of 42 patients with osteoarthritis, a formula containing ashwagandha, Boswellia serrata, Curcuma longa and zinc was administered for three months. The result was a significant drop in both pain and disability arising from the arthritis.


Unsurprisingly, it seems that much of the research conducted on ashwagandha has focused on its anti-cancer properties. From what they’ve uncovered so far, ashwagandha may be counted as one of the most potent anti-carcinogenic and anti-tumor treatments available, and without toxic side-effects. In mice, 200 mg per kg of ashwagandha per day was shown to protect them from the tumor-inducing effect of urethane, to help maintain healthy body weight and to prevent urethane-induced mortality. Clearly, if you ever accidentally knock back a glass or urethane, this herb is just the ticket. (Please don’t try that at home.)

Other studies indicate a similar function, with Chinese hamsters benefiting from the anti-tumor and radio-sensitizing effects of ashwagandha. More recent lab tests also show that human cells receive a protective effect against cancerous attacks, concluding that “the leaf extract of ashwagandha selectively kills tumor cells and, thus, is a natural source for safe anticancer medicine.”

Obligatory but Important Disclaimer: I’m in no way suggesting anyone discontinue traditional cancer therapy or rely on this or any herb or supplement for the treatment of any medical condition.


If there’s one thing that an adaptogen does well, it’s kick stress in the butt. And ashwagandha does not disappoint. As usual, there’s plenty of rodent-based research showing that ashwagandha protects against stressful scenarios, such as 474 continuous minutes of swimming. But throw a load of ashwagandha at a bunch of stressed out Homo sapiens, and you’ll find similarly significant protective effects. This study, for example, took 64 patients suffering from chronic stress and showed that 300 mg of ashwagandha root supplementation for 60 days dramatically lowered cortisol levels and reduced all marks of chronic stress.

Not bad, for a plant that smells like a stinky horse.

Other Benefits

Chances are, there’s enough here to keep you going, but it’d be rude of me not to mention some of the other benefits ashwagandha appears to provide. Here’s the quick and dirty:

Astragalus Research

Moving right along, it’s time to get the lowdown on astragalus. As with all adaptogens, astragalus appears to be dynamite against stress (that being a prerequisite, after all), so I’m not going to delve into that again. You’ll just have to trust me. But for everything else, here goes….

Cardiovascular Health

Astragalus has been shown in several studies to improve symptoms of ischemic heart disease, myocardial infarction, heart failure, and to relieve anginal pain. That being said, its close Mongolian cousin, Astragalus mongholicus, may just take the prize in this department. It’s been shown to exhibit strong antioxidant properties, improve lipid profiles, reduce risk of coronary heart disease and lower risk of cardiovascular disease in general.


Research conducted on mice indicates that astragalus injections can offset the symptoms of anemia and promote the creation of new blood cells. While promising, there definitely needs to be more research conducted in this area, preferably on compliant humans.


You’ll see plenty of studies singing the immunity focused praises of astragalus, especially with regards to colds and the flu. Apparently, there’s some substance to the claims. In particular, the collection of polysaccharides in astragalus appear to boost immunity, encourage proliferation of immuno-protective cells, lower risk of viral infection, and act as a capable companion to hepatitis B vaccinations.


Yes, yes, of course this one was going to turn up at some point: it always does with adaptogens. A meta-analysis that examined 34 astragalus-cancer studies representing over 2800 patients found that twelve of those studies reported reduced risk of death after 12 months, and 30 of them showed improved tumor response data. Not bad odds.

Other research suggests that astragalus might in some cases offer a viable replacement for chemotherapy as it shows similar efficacy to chemotherapeutic drugs minus the horrible side effects. Personally, I’d want to see more research here, but it’s an intriguing thought. (Previous disclaimer noted of course.)

Holy Basil Research


Perhaps due to its historic popularity in much of Southeast Asia and India, research relating to the anti-diabetic effects of holy basil dates way back. That research has continued unabated in the last two decades, with tests on diabetic rats showing significant reductions in fasting blood glucose, serum lipid profile, total cholesterol, and plenty more besides. Most of this is placed firmly on the causative doorstep of holy basil’s potent antioxidant effect.


Another meta-analysis of research examining the link between holy basil and cancer noted that this herb “could be useful in radiation protection of healthy individuals engaged in radiation related work and for reducing the side effects of radiotherapy in cancer patients.” The brains behind the braun? A heady mix of phytochemicals, including eugenol, rosmarinic acid, apigenin, myretenal, luteolin, and carnosic acid. 


This study demonstrated that holy basil possessed “significant antiulcer activity against aspirin-, indomethacin-, alcohol-, histamine-, reserpine-, serotonin- and stress-induced ulceration,” along with gastric ulcers. A later study found much the same thing, noting that holy basil exhibited potent anti-ulcerogenic and ulcer-healing properties, and was a likely candidate for peptic ulcer disease treatment.


Holy basil appears to set itself apart from many of the other adaptogens on account of its strong antimicrobial abilities. An in-lab study examining the effect of holy basil extract on everyone’s favorite microscopic villain, Streptococcus mutans, showed that a 4% solution created a 22 mm zone of inhibition. Another study found that holy basil worked well against Gram-positive bacteria, and “could be very useful in the discovery of novel antibacterial/antimicrobial agents.”

Adaptogen Cautions

The beauty of all three of these herbs is that, study after study, scientists continue to note how few side effects result from their use. What’s more, the side effects that do rear their ugly heads are often minor, and due in large part to herb overuse or overdose. Slow and steady wins the race, when it comes to adaptogens.

The side effects of ashwagandha are happily few and far between, and typically only occur from large doses over extended periods of time. Common side effects that result in these instances include diarrhea, upset stomach, nausea and maybe the odd bout of vomiting.

Perhaps the biggest complication that can result from taking ashwagandha would be during pregnancy. There’s simply not enough scientific evidence to mark it as safe for mothers-to-be and breastfeeding mothers-that-are. What research has been conducted shows that ashwagandha may exhibit spasmolytic activity in the uterus, which can lead to premature birth.

Once again, taking ashwagandha in conjunction with any sedative-type medications is probably a no-no, on account of its own drowsiness-inducing properties. It’s also best to avoid ashwagandha if you’re on diabetic or blood pressure medications, as it can interfere with both.

Interestingly, I couldn’t find any listed side effects of astragalus supplementation in the literature. If I had to guess, however, I’d say the body would let you know if overdose levels had been reached—vomiting, diarrhea, nausea, that kind of thing.

Pregnant and breastfeeding mothers should probably be wary of astragalus. Another thing to consider is this herb’s purported immune-boosting effect. While this may be just the ticket for those constantly suffering from the sniffles, folks beset with an autoimmune condition like MS or rheumatoid arthritis might not do so well on it.

Side effects of holy basil include coughing or peeing blood, blood-thinning effects, lowering of blood sugar, possible infertility at high doses, and premature labor.

Because of its blood-thinning effects, supplementing with holy basil if you have a blood clotting issue probably isn’t a great idea. And mixing it with sedatives isn’t the best course of action either.

Getting Your Hands on the Good Stuff

In last week’s article on ginseng, I stressed the importance of knowing your medicine. 

First and foremost, you should be fully conversant with the Latin name of each and make a point of scouring the ingredients (and active ingredients) listed on the supplement or product label. Said label should explicitly state the herb is the key (and preferably only) ingredient in the supplement. If the supplement employs a range of herbs, as is common in traditional Chinese or Ayurvedic concoctions, the herbs should at least be towards the top of the ingredients list. Exercise caution when taking blends. 

Also important is the way in which the adaptogen was cultivated and harvested. While there’s assuredly plenty of good quality sources from Asia, all three herbs are grown in the U.S., where governing bodies can presumably ensure their compliance with applicable food and supplement laws. This should reduce the carbon footprint of your supplement to boot. Additionally, going for the pricier organic adaptogenic supplement is always a good idea, as there’s a good chance your non-organic alternative has been thoroughly doused in fertilizers and herbicides, and likely grown in nutrient-poor soils. Kind of defeats the purpose, right?

Perhaps the best option of all is to pop down to your local dispensary and ask them if they have loose-leaf, organic ashwagandha, astragalus or holy basil. Buying loose leaf in bulk is almost always a lot cheaper than buying pre-packaged supplements, and you can steep all three in boiling water to make a therapeutic tea, happy in the knowledge that there’s no hidden nasties in your beneficial beverage.

Thanks for reading, folks. Hopefully that’s answered a few questions you might’ve had about adaptogens, and piqued your interest a little. Tell us about your experiences with adaptogens in the comments section below.

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TAGS:  immune health

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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