The internet is full of supposedly “amazing,” “natural” cure-alls for anxiety. Unfortunately, a lot of these claims are over-hyped, and often not based on science! In this post, we’ll run through some of the lifestyle, dietary, and supplement-based approaches to controlling anxiety, and review what the latest science says about each one. Do any of them actually work? Read on to learn more about what we know about the efficacy and safety of these approaches, as well as some of the possible limitations behind them.
Disclaimer: This post is not a recommendation or endorsement for any particular type of mental health treatment, either for anxiety disorders or otherwise. The only way to be sure you get effective treatment is to discuss your options with your personal doctor – and none of the complementary approaches described below should ever be used to replace what your doctor has prescribed or recommended. We have written this post for informational purposes only, and its goal is simply to inform our readers about the science behind some complementary approaches to alleviating anxiety, and what we currently know about how they might work.
Common anxiety symptoms include inner turmoil, nervous behavior, and excessive rumination .
Flawed processing of threat is theorized to be the common underlying factor in contributing to anxiety disorders .
While it is certainly helpful to experience fear and vigilance in response to an actual threat, someone with anxiety will interpret non-threatening signals as threatening, thus maintaining an unnecessarily high state of worry and arousal .
Underlying this exaggerated fear response is a network of brain structures that function improperly in response to stimuli. The amygdala, which controls fight-or-flight threat response, is often overactive .
On the contrary, the prefrontal cortex, which inhibits the fear-generation of the amygdala, is underactive .
Impaired activity of the hippocampus, striatum, anterior cingulate cortex, and insula can also be involved in anxiety .
These neural “malfunctions” can be accompanied by disturbances in neurotransmitters (serotonin, norepinephrine, dopamine, GABA), neurotrophic factors (nerve growth factor, BDNF), the HPA axis, immune function, heart rate variability, and cognitive function .
Now that we know what we’re up against, here are some tools you can use to overcome anxiety.
While there are many pharmaceutical drugs that have been developed which can treat anxiety relatively safely and effectively, it is unfortunately also the case that these can often have negative side-effects in some people .
For these reasons, there’s a lot of people out there who are skeptical about jumping right into using medical drugs to control their anxiety, and who are curious about complementary approaches that might be more “natural”, or which don’t rely on psychiatric medications .
However, before we begin we want to stress that this post is not an endorsement for- or against any particular mode of treatment! Nor are the strategies outlined in this post intended to be used as a replacement for conventional medical care in any way.
If you are ever diagnosed with a mental health condition of any kind, the only way to decide what the best treatment for your specific case might be is to discuss it with your doctor. Only a fully-qualified medical professional fully understands all the different advantages and drawbacks associated with the many different possible modes of treatment – and they will work with you to come up with the safest and most effective approach for your individual needs.
With that in mind, in the rest of this post we’ll discuss some of the many non-drug-based treatments for anxiety and other related mood symptoms, and what science currently says about them.
CBT is one of the most widely-used evidence-based strategies for reducing anxiety .
People who do CBT aim to develop coping strategies to solve current problems and modify unhelpful cognitive patterns (thoughts, beliefs, and attitudes), behaviors, and emotions .
CBT is traditionally delivered in-person by therapists, but is also sometimes administered over the internet with or without therapist involvement (also known as “self-guided” forms of therapy).
Because therapist involvement is not always feasible (or even preferred) for some people, self-guided CBT can also be used. Self-guided internet-based CBT reportedly reduced general anxiety, social anxiety, fear of public speaking, and depression in studies of 235, 81, and 127 people [13, 14, 15].
CBT has been claimed to reduce cognitive reappraisal frequency, subtle avoidance, cognitive distortions, safety behaviors, and rumination .
On a biological level, these changes may be due to CBT reducing activity in the amygdala and hippocampus – brain areas which are involved in emotional processing – and increasing activity in the prefrontal cortex and anterior cingulate cortex – which perform cognitive processing .
MoodGYM is a freely available and moderately effective online cognitive behavioral therapy program for anxiety .
Self-guided CBT is often not as effective as in-person CBT – but at least one meta-analysis has concluded that self–guided CBT can still have at least some positive effect on anxiety .
According to some researchers, one of the biggest challenges of self-guided CBT is low participant adherence to the protocol . Therefore, individuals who want to perform self-guided CBT should consider their commitment to the program before starting.
The practice known as “mindfulness” is simply paying full attention to what’s happening in the present moment . It can be performed throughout the day by being “in-tune” to what you are experiencing, although it is often developed through meditation techniques as well.
Meditation is a type of mental training that aims to improve attentional and emotional control .
Meditation can be “attention-focused” (such as “transcendental meditation” and “mantra meditation”) or “awareness-focused” (as in “mindfulness meditation”) . These three types are the most-studied forms of meditation for anxiety. However, some have reported that mindfulness meditation may be the only form of meditation that reliably improves anxiety .
The goal of mindfulness meditation is detached self-observation. Think of it as becoming a “witness” rather than a “judge” of events that happen about you (sounds, inner thoughts, etc.).
During mindfulness meditation, a person is typically instructed to concentrate on one main object (usually their breath) in order to stabilize their attention, and then expand their awareness “outward” towards bodily sensations, thoughts, memories, emotions, perceptions, intuitions, etc. This “expansion” happens gradually over a number of meditation sessions as the person gains more practice and experience with the technique .
According to one study, one single twenty-minute session of mindfulness meditation was reported to reduced anxiety in 15 healthy subjects .
Additionally, mindfulness-based stress reduction was reported to decrease social anxiety with the same effectiveness as CBT in a study of 108 participants .
A systematic review of scientific literature recently concluded that mindfulness-based cognitive therapy is an effective approach for reducing anxiety .
A region of the brain called the anterior cingulate cortex is believed to control executive attention to resolve emotions . Relatedly, reduced activity in this brain region has been associated with generally higher levels of anxiety .
However, experienced meditators have been reported to have greater anterior cingulate cortex activity , and meditation therapy improves anterior cingulate cortex activation . Therefore, this may be one of the mechanisms by which practicing meditation leads to anxiety relief over time.
According to other studies, increased dorsolateral prefrontal cortex activation follows from practicing a mindfulness-based stress reduction program in people with social anxiety . The dorsolateral prefrontal cortex is believed to be centrally involved in working memory, cognitive flexibility, and planning .
According to one study of a mindfulness-based stress reduction program, participants were reported to show lowered amygdala activation, ventrolateral prefrontal cortex activation, and increased functional connectivity between the amygdala and prefrontal cortex regions . These changes have been proposed to be responsible for some of the associations with decreased anxiety symptoms.
Heightened amygdala activation is frequently reported by studies on multiple different forms of anxiety , although ventrolateral prefrontal cortex activation is associated with social anxiety, specifically .
It has also been reported that people who meditate may have increased GABA levels, and reduced levels of cortisol and norepinephrine, which may further contribute to some of the effects observed in mindfulness meditation studies [35, 36].
Guidelines for meditation are readily available through many websites and consumer apps.
“Applied relaxation” is the name for a technique used to develop relaxation skills through diaphragmatic breathing and progressive muscle relaxation. These techniques are typically applied in response to early signs of anxiety .
According to a handful of studies, applied relaxation techniques have been reported to reduce general anxiety, excessive worry, and tension in studies of 41, 26, and 18 adults with general anxiety [38, 39, 37]. In some cases, these improvements were reported to be maintained for up to one year after initial treatment.
According to one case study, those who practiced applied relaxation became more accepting, mindful, and non-judgmental of their perceptions and thoughts . The development of these characteristics was associated with lower anxiety.
There is also some evidence that applied relaxation improves anxiety by reducing muscle tension . However, more research is needed to fully support this claim.
Computer-delivered applied relaxation was reported to be as effective as therapist-guided applied relaxation in reducing emotional stress and improving relaxation, as reported by a study of 60 adults .
A large body of evidence supports the benefits of yoga in reducing anxiety .
For example, practicing yoga was reported to improve mood, quality of life, and anxiety compared to a walking group in a study of 34 participants .
According to one study, yoga practice reportedly reduced anxiety in 300 individuals .
One study reports that participation in a 2-month yoga class reduced self-perceived anxiety levels in 65 women suffering from anxiety disorders .
Among 20 patients with hypertension, yoga was reported to reduce blood pressure, alleviate stress, and reduce anxiety and other negative emotions .
In 238 individuals with hypertension, hatha yoga was associated with decreased heart rate, blood pressure, anxiety, and perceived stress .
A type of yoga called Iyengar yoga was reported to reduce blood pressure, anxiety, and perceived stress in 20 women with restless-leg syndrome, as well as improved their overall mood and sleep quality .
A yoga program called trauma-sensitive yoga has been associated with reduced symptoms of PTSD, depression, and anxiety in women with PTSD stemming from intimate-partner violence .
A group yoga therapy program reportedly lowered anxiety and stress in patients with PTSD .
Although the precise biological mechanisms behind yoga’s effects are not yet fully known, some early evidence provides some clues.
Some researchers have proposed that yoga may reduce anxiety by improving HPA-axis function and increasing GABA. Yoga was also reported to reduce levels of salivary cortisol, which was accompanied by reduced depression, anxiety, and perceived stress, in several studies in 56, 59, and 46 individuals [53, 54, 55].
According to one study, just a single yoga session was reported to increase GABA among 8 yoga participants .
Many studies provide evidence for the potential benefits of regular exercise. For example, people who exercise regularly are reported to experience lower levels of neuroticism, anxiety, and depression .
Conversely, lack of regular physical activity has been associated with an increased risk of anxiety .
Some studies provide evidence that some of the potential benefits of exercise aren’t just limited to people with specific mental health conditions; for example, exercise has also been reported to reduce anxiety in people without a diagnosed anxiety disorder [61, 62].
According to one study, just a single session of aerobic exercise was reported to reduce anxiety sensitivity in a randomized controlled trial (RCT) of 21 adults .
Similarly, exercising on a treadmill for 20 minutes at 70% of maximum heart rate just 3 times per week was reported to lead to reduced anxiety sensitivity in 19 healthy adults .
In another study of 24 women, substantial decreases in anxiety were reported following 20 minutes of aerobic exercise at roughly 90% maximal heart rate .
Both aerobic exercise and resistance training have been reported to reduce anxiety sensitivity – however, only aerobic training lowered the anxiety-related sensations after inhalation of carbon dioxide (a common task for inducing anxiety in research studies) in a 77-person study .
One study reports that high-intensity interval training (HIIT) helped alleviate anxiety symptoms in 20 schizophrenic patients .
Although exercise promotes inflammation in the short-term, regular exercise has been reported to result in long-term anti-inflammatory and antioxidant effects in the brain .
Because neuronal inflammation and oxidative stress are key factors that can sometimes contribute to anxiety , the anti-anxiety effects of exercise are believed to be due (at least in part) to exercise’s protective effects on inflammation and oxidative stress.
Exercise has also been reported to increase levels of serotonin, dopamine, and norepinephrine, as well as endorphins, throughout the brain [70, 71], which may further account for some of its potential effects.
According to one study, aerobic exercise reportedly led to increased BDNF levels in 12 panic disorder patients compared to 12 control patients .
People with chronic anxiety are often reported to have an overactive HPA axis (one of the major stress-related systems in the brain). Regular exercise has been linked to reduced HPA-axis reactivity in studies of both humans and animals [73, 74].
Heart rate variability measures how much and how often your heart rate deviates from your normal “baseline” heart rate.
A higher heart rate variability (more inconsistent, e.g. varying between 50 to 75 bpm while at rest) is believed to be desirable, as it may indicate a dominance of the “rest-and-digest” (parasympathetic) nervous system.
In contrast, lower heart rate variability (e.g. staying between 65 and 70 bpm, like a metronome) indicates a dominance of the “fight-or-flight” (sympathetic) nervous system, which has been linked to generally increased levels of stress and inflammation .
In contrast, many forms of anxiety have been associated with low heart rate variability .
“Heart rate variability biofeedback training” is a technique that involves breathing for a period of time (suggested 20 minutes twice per day) at the frequency at which maximum heart rate variability is generated voluntarily for each individual. Usually, this is between 4.5 and 6.5 breaths per minute . This breathing frequency is termed “resonance” breathing.
Similarly, a recent meta-analysis concluded that heart rate variability biofeedback training may considerably reduce overall levels of anxiety and perceived stress .
It is believed that some of the brain regions involved in regulating heart rate variability are the amygdala and medial prefrontal cortex, which are also believed to be responsible for perceptions of threat and safety .
This type of training also involves slow diaphragmatic breathing, which may stimulate the vagus nerve (the nerve that connects the gut to the brain). Vagal pathways to the brain affect brain regions believed to be involved in regulating mood (such as the locus coeruleus, insula, hippocampus, and amygdala) .
Heart rate variability has also been linked to the functioning of the body’s inflammatory response . For example, increasing the heart rate variability was reported to reduce inflammation in studies of 45 and 11 people [89, 90]. Inflammation is also often elevated in people with anxiety disorders [91, 92], and so this mechanism may be part of the explanation for why heart rate variability has been associated with anxiety levels.
Use a biofeedback device to find your resonance breathing frequency (which is relatively constant) and spend 10-20 minutes per day breathing at this frequency.
One way to receive biofeedback on your heart rate is by using a heart rate monitor (chest strap or finger sensor) which syncs to a smartphone app.
The iThlete biofeedback app has been validated for accuracy . Other common apps include Bioforce, HeartRate+, and Sweet Beat/DailyBeat, although these apps have not yet been scientifically validated.
The app HRV4Training does not require a heart rate monitor, and has been validated .
Biofeedback training requires equipment that may be costly.
While cognitive-behavioral therapy (CBT) teaches people to deal with thoughts as they arise, cognitive bias modification targets thoughts earlier in the cognitive process. Biases toward a threat that have been reported as common in individuals with anxiety issues include:
- “Attention” biases: preferentially paying attention to threatening information.
- “Interpretation” biases: comprehending emotionally ambiguous information as threatening rather than neutral.
- “Memory” biases: storing and/or retrieving threatening information more often than neutral- or positive information .
Cognitive bias modification is the practice of “re-training” the above biases using computerized tasks. According to some early studies, cognitive bias modification may lower anxious behavior at clinically-relevant levels .
Cognitive bias modification may even be more effective than CBT in some cases. For example, during one year following an intervention, cognitive bias modification was reported to bring about a greater decrease in negative automatic thoughts compared to CBT and (non-treated) control groups, according to a 240-person study .
However, another randomized controlled trial (RCT) of 133 participants reported that internet-based attention bias modification combined with internet-based CBT did not improve social anxiety more than internet-based CBT alone – so the evidence is a bit mixed, and more research will be needed .
Although the mechanisms behind this technique have not been extensively studied, one preliminary study (using electrode brain monitoring) suggests that cognitive bias modification may act by improving the “top-down” cognitive processes that control emotions (specifically, via the prefrontal cortex) .
Cognitive bias modification is a relatively new technique and has not yet been shown effective in self-guided settings. Therefore, until more research is done, it is best performed under the direction of a therapist trained in administering this technique.
It has also been reported that people who have inflammatory diseases of the gut frequently also have anxiety issues , and vice versa: those with anxiety have higher rates of gastrointestinal (GI) disorders . In fact, GI disorders are the second-most commonly-occurring health condition in individuals with anxiety, second only to migraines .
Relatedly, some studies have reported that when inflammatory / GI diseases are resolved, anxiety often subsides as well, thus further reinforcing a potential link between these two types of conditions .
According to one study in mice, consumption of 50% lean beef (compared to normal mouse food) improved the diversity of fecal bacteria, and was also reported to reduce anxiety-like behaviors .
In a population-based study, 5,286 individuals took a food sensitivity blood test, and were asked to make dietary changes based on foods that caused an elevated antibody response. Among those who both reported psychological issues and followed the dietary recommendations, 40% showed psychological improvement .
(Specific probiotics will be discussed in the Supplements section of this article.)
Interestingly, some studies have reported that anxiety issues appear to follow a strong seasonal pattern – specifically, people with anxiety report worse symptoms in winter compared to any other time of year .
Individuals exposed to UVA radiation (the wavelength of natural sunlight) showed elevated serotonin levels and reported feeling less nervous compared to those who did not receive UVA radiation, according to one 53-person study .
Interestingly, the first enzyme involved in serotonin production – tryptophan hydroxylase – is found in human skin. Some researchers have suggested that sunlight may help activate this enzyme, thus increasing its activity and ultimately raising serotonin levels in the brain .
Bright light exposure has also been reported to stimulate neurogenesis (the growth and development of new neurons) in the adult rat brain, which may, in turn, contribute to reduced anxiety and depression .
Far-infrared sauna therapy combined with exercise was reported to improve emotional and psychological status in 45 patients with fibromyalgia .
While these early results are promising, the small sample size – as well as the fact that these studies were done in populations with specific medical conditions – means that more research will be needed before we can know for sure whether similar effects might be seen in healthy human users as well.
In addition to some of the behavior- or lifestyle-based approaches discussed above, there are also many supplements, herbs, and other compounds that have been touted as having potential effects on anxiety.
However, keep in mind that the science behind these is still mostly preliminary, and none of these supplements have been officially approved for treating anxiety or other related psychological conditions. Therefore, none of these compounds should be used to replace any ongoing medical treatments that your doctor has recommended.
It’s also always a good idea to consult with your doctor before trying out any new supplements or other dietary changes, as there’s always the possibility that these compounds could have adverse interactions with other ongoing medications, pre-existing medical conditions, etc. Therefore, we don’t recommend “experimenting” with supplements on your own without at least discussing them with your doctor first!
With all that in mind, here’s what some of the latest science says about several supplements that might have potential anxiety-related effects.
Kava is a plant grown in the South Pacific islands, and which is generally consumed as tea or supplement.
Kava has been reported to improve anxiety, insomnia, depression, sleep quality, cognitive function, tension, and restlessness in studies of 141, 20, and 101 healthy human participants [112, 113, 114].
In animals, Kava’s anti-anxiety effects have been reported to be quite powerful, and possibly even comparable to the effects of benzodiazepines (a class of pharmaceutical drugs commonly used to treat anxiety disorders) .
A study that performed a comparison of many different herbal anti-anxiety remedies concluded that Kava may be more effective than most other herbal supplements in reducing anxiety .
Although its precise mechanisms aren’t known for sure yet, kava has been reported to increase the activity of the GABAA receptor , and may also inhibit the uptake of the neurotransmitter norepinephrine .
However, it should be noted that there have been reports linking kava with liver toxicity (11 liver failure cases leading to liver transplants, including 4 deaths). While the toxicity of kava alone is quite small, it may interact with other drugs or increase the toxicity of other substances [119, 120]. Therefore, it is best to consult with your doctor before trying out kava – especially if you have any known liver problems.
Although its mechanisms aren’t fully clear yet, in animal studies, several components of lavender essential oil (linalool and borneol) were reported to slightly increase activity of the inhibitory neurotransmitter GABA, which may underlie some its purported anxiety-reducing effects [125, 126, 127].
According to one study in 107 humans, supplementation of 240 or 480 mg Ginkgo biloba daily for 4 weeks was reported to significantly reduce anxiety symptoms (as compared to an inactive placebo treatment) .
Ginkgo biloba extract has also been reported to reduce anxiety, depression, and dementia symptoms in elderly patients .
Apigenin is a flavonoid present in chamomile, celery, cilantro, licorice, ginkgo biloba, and passion flower . Among these foods and herbs, chamomile is believed to contain the highest levels of apigenin [134, 135, 136].
When taken in standard supplementation doses, apigenin has been reported to reduce anxiety without causing unwanted sedation-like effects .
Although its mechanisms aren’t known for sure, some early evidence suggests that apigenin may act by enhancing GABA communication by binding to GABA receptors (similar to how benzodiazepines act). Some have reported that it may also inhibit NMDA receptors of the glutamate family [140, 141].
Lemon balm (Melissa officinalis) is traditionally consumed as a tea and has long been claimed to have calming properties. Although its exact biological mechanisms are not yet fully known, it contains many psychoactive chemicals , with rosmarinic acid as its most psychoactive compound .
According to several studies in human users, supplementation ranging from 300-1,600 mg of lemon balm extract was reported to improve anxiety, stress, insomnia, memory, mood, and cognitive processing in human studies of 20, 18, 20, and 20 participants [144, 145, 146, 147].
Some researchers have suggested that rosmarinic acid may increase levels of the inhibitory neurotransmitter GABA by blocking an enzyme that is a common target for anxiety treatment, which converts GABA to L-glutamate [148, 149].
Purple passionflower (Passiflora incarnate) is a flowering vine native to the southeast United States.
Results from one early study in 18 patients with generalized anxiety disorder suggest that purple passionflower may help reduce anxiety similar to a benzodiazepine (a pharmaceutical medication often used to treat anxiety and other psychiatric disorders) .
In another study (DB-RCT), purple passionflower supplementation before surgery was reported to reduce anxiety in 30 surgery patients .
Finally, another study reported that just a single 5,000mg dose of purple passion flower reduced heart rate after public speaking, while 500mg for 6 days was reported to reduce blood pressure during the public speaking exercise, according to a 30-person study (DB-RCT) .
Some early evidence from animal studies suggests that purple passionflower contains high amounts of GABA , and may influence hippocampal GABAA and GABAC pathways in mice . However, more research will be needed to fully understand the underlying mechanisms behind these potential effects.
Inositol has 50% of the sweetness of table sugar, and some people even use its powder forms as a sweetener. It is also commonly taken as a supplement in pre-made capsules.
Similarly, supplementation with 18 grams/day of inositol reportedly reduced anxiety and panic attack symptoms in 20 patients , as well as lowered anxiety and depression in people with binge eating disorder or bulimia .
Cannabidiol, or “CBD” for short, is one of the major bioactive compounds found in cannabis and hemp. However, it is non-psychoactive (unlike THC, the compound that makes you “high”), and is widely sold for personal use in the form of CBD oil.
However, note that CBD oil is derived from cannabis, which is a controlled substance in many countries and states. Because of this, its legal status may vary from place to place, and may even be illegal to buy or possess where you live. Therefore, make sure to verify the legality of CBD and similar products before seeking them out. (If you’re in doubt about whether you can legally access these products, don’t risk it – just check out one of the 20 other potential options throughout this post!)
CBD was also reported to reduce anxiety and distress brought on by public speaking according to another study of 24 individuals with social anxiety disorder .
If you’re looking to purchase CBD, these CBD capsules are trusted by SelfHacked.
Other studies have reported that CBD may reduce activity in the amygdala, and may increase prefrontal cortex activation – two brain structures commonly associated with anxiety .
Some other evidence suggests that activation of CB1 receptors may also influence GABA and glutamate systems, although the involvement of these specific mechanisms in some of the wider psychological effects of CBD is still being researched, and haven’t been fully confirmed yet .
Ashwagandha is an Indian herb usually consumed as ashwagandha root extract.
Ashwagandha is considered an “adaptogen” – a non-toxic substance that may help correct imbalances in the hormonal and immune systems. Some early evidence suggests that ashwagandha may help restore biological functions disturbed by chronic stress .
Additionally, ashwagandha has been reported to reduce mood fluctuations and anxiety in 51 women with menopausal syndrome , and some researchers have even suggested that extracts of ashwagandha may be useful in treating anxiety disorders in conventional psychiatric practice .
According to a handful of animal studies, ashwagandha has been reported to exert some “anti-anxiety” effects similar to the pharmaceutical drug lorazepam . Other studies report that it acts similar to a mood stabilizer when treating cases of anxiety and social-isolation-induced behavior [173, 174]. Finally, it has also been reported to alleviate the OCD-like symptoms in animals .
Although its mechanisms are still being actively studied, some early findings suggest that ashwagandha may decrease cortisol levels and levels of perceived stress according to a 64-person study (DB-RCT) .
The beneficial impact of probiotics on mental health is gaining prominence as early studies shed light on the significant influence of gut microbiota. “Psychobiotics” describe a class of probiotics that have been claimed to benefit those with psychiatric illness, by helping the body to produce and transport various important neurotransmitters .
Lactobacillus and bifidobacterium are two types of bacteria that have been studied in the treatment of anxiety . Lactobacillus and bifidobacterium inhabit the gut, and have been reported to be involved in carbohydrate energy conversion [181, 182].
In one animal study, chronic L. plantarum intake reportedly increased dopamine and serotonin levels, and reduced anxiety-like behaviors in mice. It was also reported to reduce pro-inflammatory cytokines, as well as increase anti-inflammatory cytokine levels of mice subjected to early life stress [184, 185].
In another animal study, L. rhamnosus supplementation was reported to reduce anxiety and depressive behaviors, and may have even altered brain GABA gene activity in mice .
Relatedly, L. helveticus supplemented was reported to protect against the negative effect of a Western-style diet on anxious behavior in mice .
B. longum reportedly lessened anxiety-like behavior in mice with infectious colitis . The authors of this study concluded that these effects appear to be mediated by the vagus nerve pathway .
5-HTP is a naturally-occurring amino acid which the brain uses as one of the main “ingredients” (metabolic precursors) to produce the neurotransmitter serotonin, which is widely believed to be heavily involved in mood.
It is available over-the-counter as a dietary supplement, and is believed to help increase overall serotonin levels in the brain .
In one human study in 15 young adults with anxiety due to unreciprocated romanticism, six weeks of supplementation with 5-HTP was reported to decrease anxiety by increasing blood BDNF and serotonin levels .
Similarly, another human study reported that just a single 200-mg dose of 5-HTP was able to partially alleviate panic attacks in 24 patients with panic disorder .
Because this amino acid is one of the main precursors for making serotonin, 5-HTP is believed to exert its effects primarily by raising brain serotonin levels .
A few early studies back this up. For example, L-Theanine (taken after the performance of mental tasks) has been reported to alleviate symptoms of stress, while also lowering heart rate and blood pressure, in two studies of 12 and 14 participants each [201, 202].
Similarly, daily L-theanine supplementation was reported to reduce anxiety in one study (DB-RCT) of 20 schizophrenic patients, and reportedly had relaxation-promoting effects in 20 healthy individuals .
While the sample sizes in these studies are relatively small, these preliminary results are nonetheless promising, and will hopefully be followed up by more future studies in larger numbers of healthy human users.
Some early evidence from animal studies suggests that L-theanine may act by increasing brain levels of several important neurotransmitters, such as GABA, dopamine, and serotonin .
Black seed (Black Cumin, Nigella sativa) is a flowering plant native to south and southwest Asia.
Black seed supplements were reported to help stabilize mood, decrease anxiety, and even improve cognitive function in one early study of 24 healthy adolescent males .
Black seed oil has also been reported to potentially improve inflammation, blood pressure, and anxiety, without notable side effects, according to several studies in both animals and humans [206, 207, 208, 209].
Thymoquinone, a major component of Nigella sativa, was reported to increase the activity of the inhibitory neurotransmitter GABA in mice, which may underlie some of black seed’s claimed effects .
Bacopa monnieri is an herb generally taken in capsule or powder form. It should be taken with a meal because many of its components are “fat-soluble” – that is, they require dietary fats to be successfully absorbed by the body.
According to one early human study (DB-RCT), supplementation with 300mg of bacopa monniera for 12 weeks was reported to reduce anxiety compared to placebo .
Bacopa supplementation has also been reported to reduce cortisol levels and overall stress in another study of 17 healthy humans .
According to one animal study, bacopa was also reported to reduce mixed anxiety-depressive disorder in mice .
Although its mechanisms are not yet fully known and probably quite complex, some early results from studies in rats suggest that bacopa may act by increasing levels of the major neurotransmitters norepinephrine, serotonin, and dopamine, and may also help normalize blood corticosterone levels previously compromised by stress .
A few case studies have reported improvements in depression, anxiety, and sleep within one week of starting magnesium supplementation . However, these results were only based on a few individual human users, and more large-scale trials in healthy human participants will be needed to confirm these effects.
According to some researchers, magnesium’s potential anti-anxiety effects may be due to its ability to reduce the activity of the HPA axis (a major brain system involved in stress regulation)  as well as inhibiting NMDA receptors .
Low levels of omega-3 fatty acids have been associated with increased levels of social anxiety in a 49-person study .
In one study (DB-RCT) of 34 healthy human participants, omega-3 supplementation of 2.5 grams/day was reported to reduce anxiety symptoms, as well as decrease levels of interleukin-6 (a major pro-inflammatory cytokine) .
Similarly, according to another study (DB-RCT), supplementation with 3 grams of omega-3 was reported to reduce anxiety in 11 substance abusers .
In one study on rats, DHA (an omega-3 fatty acid) was reported to reduce levels of TNF-a, IL-6, and nitric oxide synthase, which may suggest that at least some of its effects may be due to reduced inflammation – although follow-up studies in humans will be needed to confirm this .
On the other hand, other animal studies have reported that EPA (another omega-3 fatty acid) may help increase hippocampal neurogenesis, which suggests that there are other important mechanisms to be discovered in addition to some of the potential anti-inflammatory effects .
Gotu kola (Centella asiatica) is a plant found in the South Asian wetlands, and which has been traditionally used as a culinary vegetable and medicinal herb.
In one placebo-controlled study, Gotu kola was reported to suppress the startle response in 40 healthy adults .
Some early evidence from a study in rats suggests that Gotu kola may act by activating glutamic acid carboxylase, an enzyme that increases GABA levels in the brain .
Skullcap herbs include American (Scutellaria lateriflora) and Chinese (Scutellaria baicalensis) skullcap herbs. They contain bioactive flavonoids, which are believed to act as potent antioxidants with numerous purported health benefits .
According to one small-scale study in humans, American skullcap was reported to decrease anxiety in 19 adults (when compared to placebo) .
Some evidence from animal studies suggests that Chinese skullcap supplementation may help reduce stress-induced anxious behaviors and blood corticosterone levels, which may point towards some of the underlying mechanisms behind its effects .
Although there are many different interesting compounds in these herbs, wogonin – which is believed to be the primary active flavonoid in Chinese skullcap – was reported to reduce anxiety-like behavior and enhances GABAA receptor activity in mice .
Although human studies are currently lacking, both honokiol and magnolol have been reported to reduce depression and anxiety in animals [232, 233, 234]. Some researchers have proposed that these effects may be due to the activation of GABAA receptors [235, 233].
However, more research will be needed to know if the effects and mechanisms are similar in healthy human users as well, so these early results from animal studies should be taken with a grain of salt.
”Hops” (Humulus lupulus) are most commonly known for their role as a flavoring and preserving ingredient of beer. However, some early evidence suggests that hops may have some sedative properties.
For example, non-alcoholic beer (still containing hops like regular beer) consumed with dinner for 14 days was reported to reduce anxiety and improve sleep in two human studies of 17 and 16 participants each [236, 237]. In the 16-person study, overnight serotonin levels were also reduced in the treatment group, suggesting a possible role of hops in the serotonin-melatonin pathway, which is vital to the circadian rhythm .
Although the mechanisms are mostly unknown, one preliminary study in cells reported that adding a small amount of beer to frog egg cells elicited a strong GABAA response, and that adding a small amount of hops strengthened GABAA receptor transmission . Nonetheless, more research in living animals and human users will be needed to further clarify the reasons for hops’ potential effects.
Valerian (Valeriana officinalis) is a flowering plant historically used in perfumes, and which is often supplemented in the form of tea or an extract of the root.
According to one preliminary human study, valerian supplementation (500mg twice daily for 60 days) was reported to reduce anxiety, stress, and depression in a study of 33 healthy individuals .
Although more human studies (with larger sample sizes) will be needed to confirm these effects, some animal studies have also reported that valerian may potentially reduce anxiety-like behaviors [241, 242].
Some researchers have suggested that the anti-anxiety effects of valerian may be due to its ability to increase the strength of GABAA signaling, although this research is still in a very early stage .