Adaptogen Side Effects: What You Need to Know

Adaptogens are natural herbs and mushrooms that help us adapt to stress and restore balance across key body systems. Prized for their stress-busting and energy-enhancing benefits, adaptogens from ancient herbalism practices are now used in nutritional supplements for mental clarity, adrenal support, athletic performance. mood balance and more.

These traditional herbs have a good reputation for being safe and well-tolerated, but they are biologically active and can have side effects, especially when they are used incorrectly (for example, taking too much) or used by individuals with other health concerns.

In this article, we will talk about some of the most popular adaptogens and their potential side effects. We'll also give tips on how to take these powerful herbs for maximum benefit and minimal risk of adverse effects. Let's get to it!

What Are Adaptogens?

Adaptogens are a class of botanicals and fungi that help the body resist and recover from physical, emotional, and environmental stress. The concept of adaptogens emerged from Russian research in the 1940s and was defined by three core criteria:

1. They are non-toxic at normal doses.
2. They help the body deal with all types of stressors in a non-specific way.
3. They promote balance (homeostasis) across multiple body systems.

By definition, adaptogens are natural, non-toxic and well-tolerated by the body.

However, like other herbal supplements, bad usage practices (such as excessive dosage) and individual sensitivities may still cause side effects.

Common adaptogens include Ashwagandha, Rhodiola rosea, Schisandra, Eleuthero, Holy Basil (Tulsi), Bacopa monnieri, Panax ginseng, and Cordyceps.

Check out our Ultimate List of Adaptogens article

How Adaptogens Work in the Body

Adaptogens mostly work via the hypothalamic-pituitary-adrenal (HPA) axis: the body’s main stress-response system.

The HPA axis is made up of the hypothalamus, pituitary gland, and adrenal glands. These glands work together to regulate cortisol ("stress hormone") production, metabolism, healthy immune function, and the body's overall response to stress. As they influence the HPA axis, adaptogens help to optimize wellness across several body systems.

Are Adaptogens Well Tolerated?

Adaptogens are widely considered to be safe and well-tolerated. Most adaptogens have a long history of traditional use India's Ayurveda and Traditional Chinese herbalism, with minimal reports of serious adverse effects.

Some adaptogens, especially adaptogen mushrooms, are also mainstays in local cuisine, further suggesting they are safe and tolerable.

Clinical studies suggest a good safety profile for adaptogens, showing that side effects are usually rare and mild.

However, because adaptogens are biologically active and affect complex systems like the HPA axis, they may not be the right choice for everyone, especially individuals with specific health conditions or those on certain medications. As with any supplement, responsible use and is key to ensuring safety and comfort.

Why Adaptogen Side Effects May Occur

As with other dietary supplements, it's important to stick to dosage directions when taking adaptogens. Adaptogen side effects are often (but not always) the result of simply not taking the right dosage. Taking too much of an herb increases risk of adverse effects. Some other side effects are simply out of our control, as adaptogens affect individuals differently on a case-by-case basis. Here's a quick summary of why adaptogen adverse effects may happen:

Common Reasons Side Effects Occur:

• Excessive dosage: Many adaptogens are well-tolerated at recommended levels but may cause adverse effects at high doses (usually overstimulation or indigestion).
• Improper timing: Taking energizing adaptogens like Rhodiola or Ginseng too late in the day can disrupt sleep or increase anxiety in sensitive individuals. Learn about anxiety-soothing nootropics.
• Wrong adaptogen for the individual: Some adaptogens can charge-up vitality; others are more calming. Using the wrong type for your needs can backfire.
• Lack of cycling: Continuous, long-term use without breaks may reduce efficacy or lead to side effects in some cases, especially with ginsengs or more potent extracts.
• Interactions with medications or health conditions: Adaptogens can interact with some medications or exacerbate certain medical issues.

Less Common Causes of Adaptogen Side Effects:

Some individuals experience side effects even at standard dosages due to:

• Unique individual genetics or supplement sensitivities
• Gut issues that may affect absorption and metabolism
• Unknown interactions with other supplements or diet

Potential Negative Interactions to Consider when Taking Adaptogens:

• Ashwagandha + calming herbs or supplements: May cause excessive drowsiness or sedation, especially at high doses.
• Rhodiola or Eleuthero + stimulants (caffeine, green tea extract): Could lead to jitteriness, anxiety, elevated heart rate, or insomnia due to additive stimulant effects.
• Reishi + blood-thinning supplements (fish oil, garlic, ginkgo): Might enhance blood-thinning effects, raising the risk of bruising or bleeding.
• Schisandra + liver-support supplements (e.g., milk thistle, N-acetylcysteine): May alter liver enzyme activity and potentially affect the metabolism of other compounds.
• Cordyceps + immune-boosting supplements (echinacea, astragalus): Possible overstimulation of the immune system.
• Adaptogens + hormone-affecting supplements (DHEA, maca, tribulus): May contribute to hormone imbalance or unexpected changes in mood, energy, or menstrual cycle.

Overall, most adaptogen side effects are due to improper use, such as taking too much, taking them at the wrong time, or taking them without considering individual sensitivities or potential interactions. But when they are chosen and used correctly, adaptogens are among the safest botanical categories.

Learn about side effects of nootropics (brain-boosters)

Potential Side Effects of Top Adaptogens

Ashwagandha (Withania somnifera)

Ashwagandha (Withania somnifera), also sometimes called Indian Ginseng, is one of the most well-known and extensively studied adaptogens. Rooted in Ayurvedic wellness traditions, it is classified as a "rasayana" herb, meaning it is used to promote longevity, vitality and stress resistance.

Herbal supplement Ashwagandha is particularly noted for its effects on reducing cortisol, supporting thyroid function, enhancing physical performance, and improving mood and sleep quality.

The active compounds in Ashwagandha root, including withanolides, appear to modulate the hypothalamic-pituitary-adrenal (HPA) axis, helping to normalize stress hormone production and promote balance in times of physical or mental strain. Its calming-but-energizing effect makes it a popular supplement for individuals experiencing chronic stress, burnout, brain fog and symptoms of "adrenal fatigue."

Typical Dosages for Benefits

Most scientific evidence demonstrating Ashwagandha’s benefits use standardized ashwagandha root extract at doses ranging from 300 mg to 600 mg per day. These doses have been shown to:

• Reduce cortisol levels
• Improve perceived stress and anxiety (1)
• Enhance cognitive function and memory
• Support testosterone and reproductive health in men
• Improve strength, recovery, and endurance in athletes

Learn more about top adaptogen herbs for athletes

High Dosage and Potential Adverse Effects

While Ashwagandha is generally well-tolerated, higher doses (especially above 1000 mg per day) may increase the risk of side effects. Possible side effects include:

• Digestive upset (nausea, diarrhea)
• Daytime drowsiness (especially at higher doses)
• Thyroid hormone stimulation (may worsen hyperthyroidism)
• Interactions with sedatives, thyroid hormone medications, or immunosuppressants

Rare allergic reactions and reports of liver issues have occurred, mostly with low-quality extracts. Experts recommend starting with lower doses (300–500 mg/day of a standardized extract) and increasing gradually only if you need to.

To reduce risk of side effects, it may also be helpful to seek out reputable supplements that use high-quality, standardized extracts such as KSM-66® or Sensoril®, which have been clinically studied for safety and efficacy.

Did you know? In standardized herbal supplements, the active compounds of an herb are measured and adjusted to ensure precise levels and consistent potency across all batches that are produced.

Rhodiola rosea

Rhodiola rosea is an adaptogenic herb traditionally used in Russia, Scandinavia, and other cold-climate regions to enhance endurance, reduce fatigue, and promote mental clarity. It is known for its two-way action: it can stimulate mind and body during fatigue, and exert calming effects during chaos and agitation. Researchers note its benefits for both physical and mental performance.(2)

Rhodiola works by regulating key stress hormones and brain chemicals, such as cortisol and serotonin, and is also considered a dopamine support supplement. The primary active compounds in Rhodiola responsible for its benefits are rosavins and salidroside. Standardized extracts usually contain a 3:1 ratio of these compounds, respectively.

Rhodiola’s unique ability to modulate the hypothalamic-pituitary-adrenal (HPA) axis while also promoting mitochondrial energy production makes it particularly effective for combating stress-related fatigue, improving cognitive resilience, and enhancing exercise performance.

Typical Dosages for Benefits

Clinically effective doses of Rhodiola rosea generally range from 200 mg to 400 mg per day of a standardized extract (typically 3% rosavins and 1% salidroside). At these doses, Rhodiola has been shown to:

• Reduce mental and physical fatigue under stress
• Produce natural energizing effects relatively quickly
• Enhance focus, alertness, and cognitive performance
• Support mood and emotional resilience
• Improve stamina and recovery in athletes
• General support for managing stress more effectively

Learn more about Rhodiola Rosea brain-boosting benefits

It is usually recommended to take Rhodiola earlier in the day due to its mildly stimulating effects.

High Dosage and Potential Adverse Effects

Although Rhodiola is well-tolerated at moderate doses, high dosages, typically exceeding 600 mg per day, may lead to side effects in some individuals. Some of these side effects may include: Rhodiola is known for boosting energy and stamina, but excessive use can cause:

• Agitation or jitteriness (especially at high doses)
• Sleep disturbances or vivid dreams
• Dry mouth or dizziness
• Potential interactions with antidepressants

These effects are more common with standardized high-rosavin extracts, which have greater potency than non-standardized supplements.

Schisandra chinensis

Schisandra chinensis, also known as the "five-flavor berry" and sometimes spelled schizandra, is an adaptogen used for centuries in Chinese and Russian traditional herbal medicine practices. The plant's berries are prized for supporting vitality, stress resilience, liver protection, and mental clarity.

Schisandra is considered a "tonic" herb -- meaning it helps restore balance to multiple body systems without overstimulating or sedating. It is associated with liver-protective effects, making it unique among adaptogens for its dual action on stress and liver health. The berry also supports adrenal function and regulates cortisol.(3)

Some researchers have attributed these beneficial effects to active compounds in the berry including lignans like schisandrin, gomisin, and schizandrol.

Typical Dosages for Benefits

Clinical studies and traditional use support a dosage range of 500 mg to 1500 mg per day of Schisandra extract, standardized to contain lignans such as schisandrin A. This dose range is associated with benefits such as:

• Improved focus, memory, and cognitive performance under stress
• Enhanced endurance and reduced fatigue during athletic activity
• Support normal functioning of liver, including healthy liver enzymes and detoxification processes
• Mood balance and help for generalized anxiety disorder symptoms

Some traditional Chinese formulas include Schisandra berries in dried form, often at a dose of 1.5 to 6 grams per day, usually brewed into tea and combined in tonic blends with other herbs.

High Dosage and Potential Adverse Effects

Schisandra is generally considered to be a well-tolerated herb when used the right way. However, doses above 2000 mg per day of concentrated extract may lead to side effects, potentially including:

• Stomach upset or reduced appetite
• Skin rash or itching (rare allergy)
• Increased stomach acid production (avoid if you have GERD or other digestive concerns)

Holy Basil (Tulsi)

Tulsi (Ocimum sanctum or Ocimum tenuiflorum), also known as Holy Basil, is an important adaptogen in India's Ayurvedic health system, where it is prized for broad-spectrum benefits on stress resilience, immune support, and metabolic balance. Often referred to as the "Elixir of Life" in ancient texts, Tulsi has been traditionally used to promote clarity of mind, emotional well-being, and protection against stress-induced health concerns.

Tulsi may help to balance the HPA axis, supporting healthy cortisol rhythms and calming the sympathetic nervous system. Its adaptogenic properties are attributed to active compounds like eugenol, ursolic acid, and ocimumosides, which exert antioxidant, inflammation-regulating, and neuroprotective effects.

Typical Dosages for Benefits

Clinical studies and traditional usage support a dosage of 300 mg to 1200 mg per day of Tulsi leaf extract, standardized to its active compounds. This range is associated with benefits including:

• Reduction in perceived stress and anxiety symptoms
• Improved mood and better emotional balance
  
• Helping to maintain normal blood sugar and blood lipid levels
• Support for immune function and respiratory health

Learn more about top adaptogens for immune function

In Ayurvedic practice, Tulsi may also be consumed as a tea using 2-3 grams of dried leaf steeped in hot water, taken up to three times per day as a general wellness tonic.

High Dosage and Potential Adverse Effects

Tulsi is well-tolerated by most people when taken at normal dosages; its safety and tolerability have been validated by clinical research reviews.(4) However, doses exceeding 1500 mg per day of concentrated extract may lead to side effects, potentially including:

• Blood thinning (take care if taking anticoagulants)
• Lowered blood glucose (hypoglycemia risk)
• Nausea or slow digestion in some individuals

Eleuthero (Siberian Ginseng)

Eleuthero (Eleutherococcus senticosus), commonly referred to as Siberian Ginseng, is a woody shrub native to Northeast Asia. Although not a true ginseng (it doesn't have the active ginsenosides of Panax Ginseng), Eleuthero is widely recognized as a foundational adaptogen with a long history of use in Traditional Chinese and Russian herbal practices. It has been used to fight fatigue, enhance endurance, and support mental performance during periods of stress and overwork.

Eleuthero works mainly by supporting adrenal function and improving the body's resistance to physical, emotional, and environmental stressors. Its key active compounds, eleutherosides, are believed to be key for its beneficial effects.

Typical Dosages for Benefits

Most clinical research supports a dosage of 300-1200 mg per day of standardized Eleuthero root extract (typically standardized to 0.8% eleutherosides B and E). Benefits associated with this range include:

• Increased physical endurance and reduced exercise fatigue (5)
• Improved concentration and mental performance
• Better recovery from stress and immune system support
• Reduced impact of jet lag and seasonal immune stress

In traditional use, Eleuthero may also be consumed as a decoction (which is kind of like tea, but boiled for a long time rather than steeped) or tincture. For example, 2-4 mL of Eleuthero tincture (1:5 in 25% alcohol) can be taken 2-3 times per day.

High Dosage and Potential Adverse Effects

While Eleuthero is usually well tolerated, doses exceeding 1500 mg per day may increase the risk of mild side effects, including:

• Increased heart rate or palpitations in sensitive individuals
• Headache or irritability (rare)
  
• Elevated blood pressure (Usually mild, in sensitive individuals)
  
• Insomnia or restlessness (especially if taken late in the day)

Learn about natural sleep supplements

To minimize risk and optimize benefits, many herbalists recommend starting with 300-400 mg in the morning and increasing gradually based on individual response.

Bacopa monnieri

Bacopa monnieri, also known as Brahmi, is a foundational herb in Ayurvedic herbalism, where it is considered a Rasayana herb traditionally used to enhance cognition, ease anxiety, and promote longevity. It is classified as a mild adaptogen due to its ability to reduce stress and improve emotional resilience without overstimulating the body.

Bacopa is also known for its nootropic effects on memory, learning, and mental performance; it is especially popular as a top nootropic for studying and academics.

The herb's key active constituents called bacosides are believed to support cell-to-cell communication in the brain, enhance synaptic plasticity, and protect brain cells from oxidative stress. Bacopa also appears to modulate the hypothalamic-pituitary-adrenal (HPA) axis and promote a more balanced cortisol response to stress.

Typical Dosages for Benefits

Most research on Bacopa’s cognitive and adaptogenic benefits uses standardized extracts providing 20% bacosides. Clinical benefits have been observed at doses ranging from:

• 250–600 mg per day of standardized extract (20% bacosides), divided into one or two doses
• Lower doses (e.g., 150 mg/day) may still support stress reduction over time, though cognitive benefits are more pronounced at higher levels

Benefits reported in studies include:

• Improved memory acquisition and retention
• Reduced anxiety and improved mood balance
• Enhanced speed-of-attention (6)
• Helping to protect against stress-induced cognitive decline
• Overall stress resistance support

Learn More about Bacopa Monnieri nootropic benefits

High Dosage and Potential Adverse Effects

Bacopa is generally safe and well tolerated, especially when taken with food. However, high doses (typically above 750–800 mg per day) may increase the risk of side effects, such as:

• Digestive upset (nausea, cramping, diarrhea)
• Fatigue or sedation (more common with high doses)
• Interactions with thyroid medications or sedatives
  
• Dry mouth

In addition to these side effects, Bacopa has a mild sedative quality. It can be relaxing, but this may interfere with alertness in some people, especially at higher doses. For this reason, many people prefer to take Bacopa in the evening or before bed. Learn more about timing Bacopa supplementation

Starting with a low dose (250 mg is a good entry-level dose) and gradually increasing dosage allows people to figure out their tolerance and optimal dose for benefits while minimizing side effects.

Panax Ginseng

Panax ginseng, also known as Korean ginseng or Asian ginseng (note: American Ginseng is a separate herb), is one of the most researched and widely used adaptogens. It has been used for thousands of years in Traditional Chinese Medicine (TCM) to enhance vitality, combat chronic fatigue, and improve physical and mental performance. Panax ginseng contains active compounds called ginsenosides, which are believed to be responsible for its adaptogenic and tonic effects.

In addition to optimizing the HPA axis like other adaptogens, Ginseng is believed to support function of mitochondria -- the powerhouses of cells that produce energy for life. Ginseng is also used to support healthy immune activity and mental clarity under fatigue or stress.

Typical Dosages for Benefits

Some placebo controlled study evidence suggests the following dosages are effective for most adaptogenic and nootropic benefits:

• 200-400 mg per day of standardized Panax ginseng extract (usually containing 5–7% ginsenosides)
• Higher doses of 500-800 mg per day may be used for short-term energy enhancement or fatigue reduction

Reported benefits of Panax ginseng include:

• Reduced mental and physical fatigue
• Improved cognitive performance, especially under stress
• Enhanced immune function and resilience
• Support for blood sugar regulation
• Cardiovascular wellness support (7)

High Dosage and Potential Adverse Effects

Panax ginseng is generally safe when used at standard dosages for limited periods. However, consistently high doses -- especially above 800-1,000 mg per day -- may lead to unwanted side effects, including:

• Insomnia or restlessness
• Headaches or dizziness
• Heart palpitations or increased blood pressure (rare)
• Digestive upset or nervousness

Some individuals may experience overstimulation from ginseng, especially if they take it with caffeine or other stimulants. For this reason, it is generally recommended to use Panax ginseng in the morning or early afternoon and to cycle its use (taking it for 6-8 weeks, followed by a break) to maintain effectiveness and reduce risk of tolerance or side effects. Standardized ginseng extracts are preferred for consistency and safety.

Lion’s Mane Mushroom (Hericium erinaceus)

Lion’s Mane (Hericium erinaceus) is a unique mushroom long valued in Traditional Chinese and Japanese herbalism for its benefits on brain health, digestion, and overall vitality. Known for its white shaggy spines that look like a lion's mane, it is especially prized today as the best nootropic mushroom.

The primary bioactive compounds in Lion’s Mane are called hericenones and erinacines. They stimulate the production of nerve growth factor (NGF), a protein essential for the growth, maintenance, and survival of neurons.(8)

This action makes Lion’s Mane a popular natural option for individuals seeking to enhance memory, focus, and mood stability, as well as for those looking to support long-term brain health and resilience against stress-related cognitive decline.

Typical Dosages for Benefits

• 500 mg to 1,000 mg per day of standardized extract (fruiting body and/or mycelium)
• 1,000 mg to 3,000 mg per day of powdered fruiting body or dual extract

These doses have been shown to:

• Support memory, focus, and mental clarity
• Promote mood balance and reduce mild anxiety and depression
• Encourage nerve regeneration and protect brain health
• Help with mild age-related cognitive concerns (9)

Learn more about Lion's Mane Mushroom dosage

High Dosage and Potential Adverse Effects

With its delicious mild seafood-like flavor, Lion's Mane Mushroom has been a popular ingredient in Asian cuisine for centuries. Widely consumed, it is considered to be very well-tolerated, with side effects being rare and mild. However, higher doses -- especially over 3,000 mg per day -- may increase the risk of side effects. Potential side effects may include:

• Stomach upset (nausea, bloating, diarrhea)
• Skin rash or itching (possible allergic response)
• Asthma-like symptoms (rare, most likely happening in people who are sensitive to mushrooms)

Experts suggest starting with moderate doses (500-1,000 mg/day) and gradually increasing as needed, while keeping an eye out for any adverse reactions. As with all adaptogens and functional mushrooms, it is important to choose organic supplements that are properly sourced and undergo lots of quality checks.

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When to Avoid Adaptogens

Although adaptogens are generally pretty safe and comfortable to take, there are certain circumstances where you should avoid them altogether. These situations are best evaluated by a qualified healthcare professional, but as a starting point, here are some scenarios where caution is warranted when considering adaptogens:

• During pregnancy or breastfeeding (unless approved by a healthcare provider)
• If taking medications (e.g., antidepressants, anticoagulants, sedatives, thyroid meds)
• If you have autoimmune conditions (some adaptogens stimulate immune activity)
• If you have hormone-sensitive conditions (adaptogens may modulate estrogen, cortisol, etc.)

Best Practices for Safe Adaptogen Use

1. Start with the lowest effective dose.
2. Use adaptogens in cycles (for example, 6-8 weeks on, 1-2 weeks off).
3. Purchase from reputable brands with standardized extracts.
4. Monitor how you feel and discontinue use if adverse effects occur.
5. Consult your healthcare provider if you have any preexisting health concerns.

Summary

Adaptogens represent one of nature’s most fascinating gifts. These botanicals and fungi have helped people around the world navigate stress, boost resilience, and restore inner balance for centuries.

Today, adaptogens are widely available in supplement form, offering natural support for mental clarity, adrenal health, immune resilience, athletic performance, and mood balance. And perhaps most famously, they help adults experiencing high stress to maintain good performance. Especially in conjunction with stress management techniques.

While they are usually well-tolerated and safe for most people when used properly, adaptogens are not without potential side effects. Because they are biologically active, they can cause side effects in certain individuals -- particularly if taken in excessive doses, used inappropriately, or combined with medications or other potent supplements without guidance.

The key to benefiting from adaptogens without dealing with side effects lies in thoughtful, personalized use. Choose the right adaptogen for your individual needs, start with a low dose, and adjust gradually while monitoring how your body responds.

Ultimately, incorporating adaptogens into your dietary supplement routine may offer a natural pathway to healthy balance. By using them wisely and respectfully, we can tap into their ancient power while supporting modern health in a safe, sustainable way.