B Vitamins and Sleep: What We Know About Vitamin B6 and Vitamin B2

Vitamin B6 (pyridoxine) and vitamin B2 (riboflavin) are in some sleep formulas. We cover them in one guide because the sleep evidence for each is too thin to carry a page. This guide sets out what has been tested, what the amounts in those studies were, and what the NIH says about safety.

It is not medical advice. If sleep trouble is persistent, talk to a healthcare provider.

The Short Answer

We found no placebo-controlled trial of vitamin B6 alone or vitamin B2 alone showing better sleep in adults with insomnia. What has been tested for B6 is dreaming, and for B2 there is one small trial of B1 and B2 together.
B6 changed dream recall, not sleep. In a placebo-controlled trial of 100 people, 240 mg of B6 before bed for five nights increased the amount of dream content recalled. It did not significantly change dream vividness or other sleep variables. The B-complex group in the same trial rated its sleep quality lower and felt more tired on waking.
The one B2 trial gave B1 and B2 together. 43 people took 100 mg of each vitamin or placebo for four weeks, and sleep quality scores improved in the vitamin group. The trial cannot say what B2 did on its own.
The doses in these studies are far above the amounts on one formula’s label. The trials used 100 to 250 mg. One formula we reviewed lists 0.5 mg of each.
The NIH sets a limit for B6. It is 100 mg a day for adults from all sources, and taking high amounts from supplements for a year or longer can cause severe nerve damage. Riboflavin, the NIH says, has not been shown to cause harm.

What B6 and B2 Do

The NIH Office of Dietary Supplements says the body needs vitamin B6 for more than 100 enzyme reactions involved in metabolism, and that it is also involved in brain development during pregnancy and infancy and in immune function. Most people in the United States get enough from food, and deficiency is uncommon (NIH ODS, vitamin B6, updated June 2023). The riboflavin fact sheet says it helps turn the food you eat into energy, lists recommended amounts, and says riboflavin is not known to interact with medicines (NIH ODS, riboflavin, updated May 2022). Neither fact sheet mentions sleep.

One group of researchers offers a hypothesis that B6 acts through the conversion of tryptophan to serotonin, and it says the idea needs replication (Ebben et al., 2002). It is a hypothesis, not a finding.

What the Studies Show

Ebben and colleagues, 2002. A small placebo-controlled, double-blind study of 12 college students who took 100 mg of B6, 250 mg of B6 or placebo before bed for five days each, in a counterbalanced design. Morning reports showed higher dream-salience scores (vividness, bizarreness, emotionality and color combined) with 250 mg than with placebo over the first three days. The authors say the study needs to be replicated and shown in a sleep laboratory before the results can be considered certain (Ebben et al., 2002).
Adventure-Heart and colleagues, 2018. A replication with 100 participants from across Australia in a randomized, double-blind, placebo-controlled study. They took 240 mg of B6 before bed for five nights, and an exploratory group took a B-complex preparation. B6 significantly increased the amount of dream content recalled. It did not significantly affect dream vividness, bizarreness or color, or other sleep-related variables. The B-complex group rated its sleep quality significantly lower and reported higher tiredness on waking (Adventure-Heart et al., 2018).
Tao and colleagues, 2025. A randomized, double-blind, placebo-controlled trial of 43 people who took 100 mg of vitamin B1 and 100 mg of vitamin B2 together, or placebo, for four weeks. Perceived stress fell in the vitamin group (p < 0.05). The Pittsburgh Sleep Quality Index went from 8.0 to 6.3 in the vitamin group, while in the placebo group it went from 5.7 to 7.4. Daytime sleepiness on the Epworth scale also fell in the vitamin group. There was no significant effect on anxiety. The two groups started at different sleep scores (8.0 and 5.7), which limits how far the comparison can be read. The trial had a Macao government science fund grant, and the authors declare no conflicts. The two vitamins were given together, so it says nothing about B2 alone (Tao et al., 2025).

What the Reviews Show

Ji and colleagues, 2017. A systematic review of 26 articles on dietary and circulating micronutrients and sleep. The researchers generally supported a potential role of micronutrients, particularly iron and magnesium, in sleep stages in infants and in age-related changes in sleep in older adults. Sleep duration was positively associated with iron, zinc and magnesium levels, and negatively with copper, potassium and vitamin B12. The abstract does not name B6 or B2. The authors call the number of studies low and say dose-dependent and longitudinal studies are needed (Ji et al., 2017). The review had NIH grants.
Kamat and colleagues, 2023. A systematic review of 76 randomized trials of plant-based and natural supplements on anxiety, depression and sleep. Its abstract reports evidence of benefits of probiotics and vitamin B complexes on anxiety symptoms, depressive symptoms and sleep quality. It does not say which B vitamins, in which doses or populations, and the B-complex result in the 2018 study above was the opposite. The authors declare no conflicts (Kamat et al., 2023).

Amounts

100 mg and 250 mg of B6 for five days in the 2002 study, and 240 mg for five nights in the 2018 study.
100 mg of B1 plus 100 mg of B2 for four weeks in the 2025 trial.
Recommended intakes are much smaller. For adults aged 19 to 50, the NIH lists 1.3 mg of B6 a day, and 1.7 mg for men and 1.5 mg for women aged 51 and over. For riboflavin it lists 1.3 mg for men and 1.1 mg for women (NIH ODS, vitamin B6; NIH ODS, riboflavin).
The Yu Sleep label lists 0.5 mg of each. That is 200 times less than the 100 mg in the B1 and B2 trial, and a small fraction of what the B6 studies used.
Riboflavin absorption has a ceiling. The NIH says some supplements have much more than the recommended amounts, but the body cannot absorb more than about 27 mg at a time. The 2025 trial gave 100 mg.

Safety

Vitamin B6. The NIH says people almost never get too much B6 from food, but that taking high amounts from supplements for a year or longer can cause severe nerve damage, leading people to lose control of their bodily movements. Other symptoms of too much include painful skin patches, extreme sensitivity to sunlight, nausea and heartburn. The symptoms usually stop when the supplements stop. The upper limit for adults, from all sources, is 100 mg a day, and it does not apply to people taking B6 for medical reasons under a doctor’s care. The NIH adds that some experts recommend lower limits, and that in 2023 the European Food Safety Authority set an upper limit of 12 mg a day for all adults (NIH ODS, vitamin B6).
B6 interactions. B6 supplements might interact with cycloserine, an antibiotic used for tuberculosis, and worsen seizures and nerve damage the drug might cause. Certain epilepsy drugs could decrease B6 levels, and theophylline for asthma or another lung disease can reduce B6 levels and cause seizures. The NIH advises telling your doctor and pharmacist about every supplement and medicine you take.
Riboflavin. The NIH says riboflavin has not been shown to cause any harm and is not known to interact with any medications (NIH ODS, riboflavin).
The U.S. National Center for Complementary and Integrative Health says dietary supplements may interact with your medications or pose risks if you have certain medical problems or are going to have surgery, and that many have not been tested in pregnant women, nursing mothers or children (NCCIH, last updated January 2019).

Who Ran the Research

The 2025 B1 and B2 trial had a Macao government fund and declares no conflicts.
The 2017 review had NIH grants, and the 2023 review declares no conflicts.
The PubMed records of the 2002 and 2018 dream studies list no funding or conflict statement, and we did not check the full texts.

Funding does not invalidate a study. It is why we say who is who.

What We Do Not Know

Whether B6 or B2 alone improves sleep. We found no such trial in adults with insomnia.
Whether a small dose does anything for sleep. The studies used 100 mg or more.
Whether B vitamin complexes help or hurt sleep. One trial found lower self-rated sleep quality, and a review reports benefits, without the details we need.
What B2 does apart from B1. The one trial we found gave both.
Long-term effects of high doses. For B6, the NIH links long-term high doses to nerve damage.

Questions

Does vitamin B6 help you sleep?

We found no trial showing that it does. In two small studies it increased dream recall, and in the larger one it did not significantly change other sleep variables.

Does vitamin B2 help you sleep?

We found one small trial, in which B1 and B2 were given together and sleep quality scores improved. It cannot separate B2.

How much B6 or B2 should I take?

We cannot give a dose. The NIH upper limit for B6 is 100 mg a day from all sources, with a lower limit of 12 mg a day set by the European Food Safety Authority. Ask a healthcare provider, especially if you take medication.

Does B6 cause vivid dreams?

In two small placebo-controlled studies, B6 taken before bed increased a dream measure. The larger study found more dream content recalled but no significant change in vividness.

Sources Cited in This Guide

Ebben M, Lequerica A, Spielman A. “Effects of pyridoxine on dreaming: a preliminary study.” Percept Mot Skills. 2002. Read September 19, 2026 (abstract). PMID 11883552
Adventure-Heart DJ, Madden NA, Delfabbro P. “Effects of Vitamin B6 (Pyridoxine) and a B Complex Preparation on Dreaming and Sleep.” Percept Mot Skills. 2018. Read September 19, 2026 (abstract). PMID 29665762
Tao Y, Wu M, Su B, et al. “Impact of Vitamin B1 and Vitamin B2 Supplementation on Anxiety, Stress, and Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Trial.” Nutrients. 2025. Read September 19, 2026 (abstract and conflict statement). PMID 40507089
Ji X, Grandner MA, Liu J. “The relationship between micronutrient status and sleep patterns: a systematic review.” Public Health Nutr. 2017. Read September 19, 2026 (abstract). PMID 27702409
Kamat D, Al-Ajlouni YA, Hall RCW, et al. “The Therapeutic Impact of Plant-Based and Nutritional Supplements on Anxiety, Depressive Symptoms and Sleep Quality among Adults and Elderly.” Int J Environ Res Public Health. 2023. Read September 19, 2026 (abstract and conflict statement). PMID 36982079
National Institutes of Health, Office of Dietary Supplements. “Vitamin B6: Fact Sheet for Consumers.” Updated June 16, 2023. Read September 19, 2026. NIH ODS
National Institutes of Health, Office of Dietary Supplements. “Riboflavin: Fact Sheet for Consumers.” Updated May 11, 2022. Read September 19, 2026. NIH ODS
National Center for Complementary and Integrative Health, NIH. “Using Dietary Supplements Wisely.” Last updated January 2019. Read September 19, 2026. NCCIH

This guide is for information and is not medical advice. Talk to a healthcare provider about medication, pregnancy, medical conditions and persistent sleep problems.