The dose of vitamin B6 shown to reduce anxiety in clinical research is 100 mg per day, taken for about a month. That’s roughly 50 to 75 times the recommended dietary allowance, which sits at just 1.3 to 1.7 mg for most adults. It also happens to be right at the tolerable upper intake level set by the National Institutes of Health, which means the effective dose and the safety ceiling are essentially the same number. That narrow margin is important to understand before you start supplementing.
What the Research Actually Shows
The strongest evidence comes from a 2022 randomized, placebo-controlled trial at the University of Reading. Participants took 100 mg of vitamin B6 (as pyridoxine hydrochloride) daily for roughly one month. The group taking B6 saw a statistically significant drop in anxiety scores, with average scores falling from 24.8 to 21.5 on a standardized anxiety scale. The placebo group showed no meaningful change.
The effect size was modest. This wasn’t a dramatic transformation, but it was a real, measurable reduction in self-reported anxiety. Worth noting: the same study found no significant effect on depression scores. B6 appears to target anxiety specifically rather than acting as a general mood booster.
The researchers believe the mechanism involves your brain’s calming chemical, GABA. Vitamin B6 is a required cofactor for the enzyme that converts glutamate (an excitatory neurotransmitter that ramps up brain activity) into GABA (an inhibitory neurotransmitter that calms it down). The theory is that higher doses of B6 shift the balance away from neural excitation and toward inhibition, essentially turning down the volume on overactive brain signaling.
Why the Dose Matters So Much
The tolerable upper intake level for adults is 100 mg per day, the exact dose used in the anxiety trial. This limit exists because high-dose B6 can cause peripheral neuropathy: tingling, numbness, or pain in the hands and feet caused by nerve damage. Most reports of neuropathy involve doses above 500 mg per day, and studies tracking people taking an average of 200 mg per day for up to five years found no evidence of nerve problems. Still, some cases have been reported at doses below 500 mg.
Adding to the complexity, the European Food Safety Authority recently set a much more conservative upper limit of just 12 mg per day for all adults, based on its own systematic review of the link between B6 and neuropathy. That’s a massive gap between the two regulatory positions, and it reflects genuine scientific uncertainty about where the safe line sits for long-term use.
If you’re considering 100 mg per day, treat it as a short-to-medium-term intervention rather than something you take indefinitely. The trial that showed benefits lasted about one month. Going beyond that timeframe at high doses without professional guidance increases your risk of side effects that could take weeks or months to reverse.
Combining B6 With Magnesium
An eight-week randomized controlled trial looked at whether adding vitamin B6 to magnesium supplementation would improve stress relief in healthy adults with severe or extremely severe stress and low magnesium levels. The combination did produce greater stress reduction than magnesium alone. Participants also reported better physical functioning in daily life at the four-week mark compared to those taking magnesium by itself.
However, the results were more nuanced than the headline suggests. When researchers looked specifically at anxiety and depression scores, the combination of magnesium plus B6 performed about the same as magnesium alone. The added benefit of B6 showed up more in overall stress perception and physical energy than in anxiety specifically. So while the pairing is reasonable, magnesium may be doing most of the heavy lifting for anxiety in this combination.
Supplement Forms
Most B6 supplements and the one used in the key anxiety trial come as pyridoxine hydrochloride. This is the most common and widely available form. Your body absorbs it quickly through the small intestine and converts it into its active form in the liver.
You’ll also see pyridoxal-5-phosphate (often labeled P5P) marketed as a “pre-activated” form that skips the liver conversion step. Some people with certain genetic variations may convert pyridoxine less efficiently, making P5P appealing in theory. But the clinical anxiety research used standard pyridoxine hydrochloride, so that’s the form with direct evidence behind it. Supplements are commonly available in 25 mg, 50 mg, and 100 mg tablets.
Getting B6 From Food
The amounts of B6 you’ll get from food are far below the 100 mg therapeutic dose, but they’re relevant for maintaining adequate baseline levels. Deficiency itself can contribute to mood problems, so ensuring you’re not running low is a reasonable first step. The richest food sources include beef liver, tuna, salmon, poultry, chickpeas, fortified cereals, dark leafy greens, bananas, papayas, oranges, and cantaloupe.
A serving of chickpeas provides about 1 mg of B6, and a serving of tuna or salmon delivers a similar amount. You’d need to eat an unrealistic volume of these foods to hit 100 mg, which is why supplementation is the only practical route to the doses tested in anxiety research. That said, a diet consistently low in B6-rich foods can leave you mildly deficient, which may worsen anxiety on its own before you ever consider high-dose supplementation.
Realistic Expectations
Vitamin B6 at 100 mg per day produced a real but moderate reduction in anxiety over about one month. It didn’t eliminate anxiety, and the average drop in scores was roughly 13%. For context, that’s a meaningful shift, similar to what some people experience with lifestyle changes like regular exercise or improved sleep, but it’s not comparable to the effect of prescription medications for anxiety disorders.
The evidence also comes from a limited number of trials. One well-designed study is promising, not definitive. If you’re dealing with mild to moderate anxiety and looking for something to take the edge off, 100 mg of pyridoxine hydrochloride daily for a month is a reasonable, evidence-backed option to try. If your anxiety is severe or significantly affecting your daily life, B6 supplementation alone is unlikely to be sufficient.