There is actually very few supplements that have been able to produce anxiety or stress relief in study settings.
The commonly used valerian root, for example, has not been seen to ease stress or anxiety. (1)
Then there are a couple of other herbs, which have been noted to ease anxiety, but with severe side effects of their own. Such as Kava, which has been implicated in cases of liver failure and St. John’s worth, which has adverse interactions with prescription medicine. (2, 3)
I have suffered from anxiety myself, and I’ve used all the supplements listed below. I got the most help from prebiotics and ashwagandha.
Supplements rarely “cure” prolonged anxiety but they may provide temporary relief. Gut treatments with prebiotics, probiotics, and some antimicrobial agent may actually cure mood disorders completely if the underlying cause for them is intestinal dysbiosis (= overgrowth of some unwanted microbial species).
So, which supplements decrease stress and anxiety?
Prebiotics and probiotics as anxiety supplements

Probiotics are pretty well-known by now. But the significance of prebiotics is not as widely understood.
Prebiotics are soluble fibers which don’t get absorbed from the small intestine but travel to the colon, where beneficial bacteria ferment them and grow their numbers.
Most notably prebiotics can stimulate the growth of the desired bifidobacteria, which provide many health benefits for humans.
When we are talking about gut health and beneficial bacteria, we are talking about the health of the whole body.
It could be said that probiotics are the seeds and prebiotic foods or supplements are the water …Or probiotics are the matches and prebiotics are the gasoline.
Aaand, let’s get back to the point. Probiotics were able to reduce anxiety and depression in a Dutch study where the subjects were given a basic multi-strain probiotic for four weeks and in a Canadian study where lactobacillus casei probiotic was administered for two months. (1, 2)
The same is true for prebiotics. In a study from Oxford, GOS prebiotics were found to be helpful in dealing with anxiety and stress-related disorders. (3) In my recent blog post, I go more into the details on why and how prebiotics treat anxiety.
At the moment, Bimuno is the only widely sold GOS-prebiotic brand. More commonly sold FOS-prebiotics are also efficient in promoting bifidobacteria growth. (4)
You can check out my in-depth post about Bimuno GOS and other prebiotics here.
See Bimuno Prebiotic in Amazon
Ashwagandha

Ashwagandha is a respected medicinal plant in traditional Indian healthcare. It is considered to be an adaptogenic herb, which is able to balance hormonal functions and mood.
That all would sound phony to me, but controlled studies have shown that ashwagandha root extracts indeed work.
In studies ashwagandha has been discovered to:
- reduce stress (1)
- reduce anxiety (2)
- reduce social anxiety (3)
- lower the levels of stress hormone cortisol (4)
- increase testosterone levels in men (5)
I use ashwagandha occasionally when stressful mood seems to overtake my mind. At these times, ashwagandha is, at least for me, amazingly efficient in shifting the awareness from anxious to relaxed.
Though if I take the herb for many consecutive days, it seems to lose its efficiency.
Many of the ashwagandha studies have been conducted using the KSM-66 ashwagandha extract, which is found in some of the ashwagandha products available.
Omega-3 fish oils for stress
I’m not a big fan of fish oil supplements. Following the omega-3 opinions of many Paleo gurus such as Robb Wolf, I ate them for years thinking they could be beneficial for everybody.
Since then studies have pointed that fish oil supplements may not be that healthy after all. It was believed that omega-3 could prevent heart disease, but the majority of new studies show no benefits from fish oil supplementation for CVD. (1)
A few studies indicate that fish oil supplementation may even be harmful. Correlations have been found, suggesting that for some people, O-3 supplementation may promote the risk of prostate cancer, higher insulin resistance, and even heart disease. (2, 3, 4)
Some studies indicate that omega-3 fats promote anti-inflammatory effects. And with our crappy western diets, we get way too much of pro-inflammatory omega-6 fats (via grains, vegetable oils and seed oils) compared to omega-3 fats. So it might be beneficial to take omega-3 fats as supplements to balance out the intake of our fatty acids.
So my current view of fish oil is that it may be beneficial if you are on a shitty diet, or there is a specific problem to which fish oil is seen to be an effective treatment.
And there indeed is at least two studies, which indicate that omega-3 fish oils reduce anxiety and provide an improvement in overall mood state. (2, 3)
For major depression, there is even more proof of fish oil supplementation being beneficial. And it can be tried out for anxiety too. I wouldn’t take fish oil for overall health, but if they do provide noticeable mood improvements, they are a supplement worth considering.
L-Theanine and anxiety

L-Theanine is a non-essential amino acid, meaning we don’t need it to live. Regular black or green teas are just about the only dietary sources of this amino acid.
The effects of L-Theanine are perceived to be relaxing without sedation. So it doesn’t cause drowsiness along with the relaxation.
Let’s see what studies have found out about L-Theanine
a) A long term double blind study in schizophrenia patients found that 400mg of L-Theanine taken daily reduced anxiety and activation symptoms. (1)
b) Two different studies have shown L-Theanine to significantly enhance alpha brain wave activity, which is linked to relaxation. (2, 3)
c) One study found that L-Theanine did not reduce anxiety in subjects who were only minimally agitated. But the 200 mg dose was able to reduce tension in those subjects with high anxiety. (4)
d) Acute stress responses were monitored in three different short-term studies. In two of the three studies L-Theanine produced relaxation while in the third, no significant effects were detected. (5, 6, 7)
L-Theanine is considered to be a pretty safe supplement. In Japan, where the supplement is popular, it’s approved to be used in all foods.
Taiyo, the manufacturer of the popular Suntheanine form of L-Theanine, has reported that L-Theanine has failed to produce any toxicity in rats even with very high doses. An American toxicology study also determined L-Theanine to be non-toxic. (8, 9)
Magnesium

Magnesium is the second most common electrolyte in the human body and an essential mineral, which has to be acquired from food.
Magnesium deficiency is known to cause depression. And magnesium supplements have been effective in reducing depression IF the patients are deficient in magnesium. (1, 2)
Same goes for anxiety and stress as magnesium plays a significant role in brain function, hormonal axis and the regulation of stress responses. (3)
So magnesium supplements may help to reduce stress and anxiety if you are deficient of the mineral.
Magnesium deficiencies are most often caused by
- Poor diet
- Obesity
- Substance abuse
- Stress
- Excess calcium intake
Low levels of vitamin D may also play a part in magnesium deficiency. (4) Modern day stressors and poor diets that provide inadequate amounts of magnesium may lead to magnesium supplements being useful with stress and anxiety.
Magnesium is like fish oil supplements in that it can be tried for a few weeks or a month to see if it helps with mood disorders.
Magnesium should be taken with food. Most common unwanted side effects are diarrhea and other gut symptoms.
Anxiety and Stress Supplements In Conclusion
It’s good to remember that while these supplements provide relief for many people, they do not fit for all. For example, when I had been under work stress for way too long, magnesium actually made me feel worse.
And the same can happen with fish oils. If using these nutrients makes the overall feeling of well-being worse, I would stop taking them.
Gut treatments are a bit trickier to analyze. Transforming the gut microbiome and killing of the bad guys may lead to cell wall remnants of the displaced microbes to be absorbed into blood stream. This may cause die-off reactions, such as headaches and insomnia.
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