Can I Take Vitamin B6 with Dayvigo (Lemborexant)?

The Direct Answer

For most adults taking Dayvigo at the approved 5 mg or 10 mg dose, a standard multivitamin or a low-dose B6 supplement (roughly 25 mg per day or less) is not expected to cause a meaningful drug interaction. No FDA labeling, clinical trial, or case report reviewed for this article identifies vitamin B6 as a substance that raises or lowers lemborexant levels, or that adds to its sedative effect.

The caution that does apply is about vitamin B6 on its own terms. Chronic high-dose B6 supplementation carries a documented risk of peripheral neuropathy, independent of any other medication a person takes. Anyone taking B6 above the amounts found in a typical multivitamin should know that risk exists and should mention the supplement to their prescriber, not because of Dayvigo specifically, but because it is good practice for any nutrient taken at pharmacologic doses.

What Dayvigo Is and How It Is Cleared

Lemborexant, sold as Dayvigo, is a dual orexin receptor antagonist that blocks the OX1R and OX2R receptors involved in wake signaling, promoting sleep onset through a different mechanism than older sedative-hypnotics. The FDA approved lemborexant in December 2019 for adults with insomnia disorder. [1]

Lemborexant is metabolized primarily by CYP3A4, with a minor contribution from CYP3A5, and its labeled plasma half-life is in the range of 17 to 19 hours, meaning it remains active into the following day. [2] The current prescribing information warns against combining lemborexant with strong or moderate CYP3A4 inhibitors and with strong CYP3A4 inducers, because these can push lemborexant blood levels outside a safe range. [2] Vitamin B6 does not appear on that interaction list. [1]

Because CYP3A4 is the pathway that matters most for lemborexant safety, evaluating any co-administered substance starts by asking whether it affects that enzyme. Human data on pyridoxine and cytochrome P450 activity have not identified a meaningful effect at doses achievable through supplementation. [3]

What Vitamin B6 Is and Why People Take It

Vitamin B6 is a group of related compounds, most commonly supplemented as pyridoxine hydrochloride. The adult dietary requirement is about 1.3 to 1.7 mg per day, but over-the-counter products range from 2 mg (typical multivitamin) to 500 mg (single-dose tablets). [4]

Common reasons people take B6 supplements include:

• Nausea and vomiting of pregnancy, often at 10 to 25 mg given up to three times daily, the same ingredient used in combination with doxylamine in prescription products for this indication [5]
• Premenstrual symptom management
• Pyridoxine-responsive conditions such as certain forms of sideroblastic anemia
• Prevention of isoniazid-induced neuropathy during tuberculosis treatment, since isoniazid depletes pyridoxal phosphate
• General wellness use with more limited evidence behind it

The link some people draw between B6 and sleep is indirect: B6 is a cofactor in serotonin and melatonin synthesis. A small early study explored whether high-dose B6 affects dream vividness. [6] That finding has not translated into any recognized clinical guidance for using B6 as a sleep aid, and the exact dose and sample size reported in older secondary summaries of this study should be verified against the original paper before being repeated as a precise figure.

B6 Toxicity Is a Real, Separate Concern

Sensory peripheral neuropathy from excess pyridoxine is well documented in the medical literature. The classic case reports describing this "megavitamin syndrome" involved chronic intake in the multi-gram-per-day range. [7] The U.S. tolerable upper intake level set by the National Academies is 100 mg per day for adults. [4] Some more recent reviews and other national bodies have proposed lower thresholds, and some clinical reports describe neuropathy symptoms at doses well below the multi-gram range described in the original case series; the exact lowest dose at which risk begins is not firmly established and varies between sources, so a specific number should not be treated as a hard cutoff. Anyone taking B6 above standard multivitamin amounts for more than a few months should have that discussed with a clinician, regardless of what other medications they are on.

Pharmacokinetics: Does B6 Change How Dayvigo Is Metabolized?

No published data show that pyridoxine, pyridoxal, or pyridoxamine inhibit or induce CYP3A4 at doses used in supplementation. A review of vitamin and cytochrome P450 interactions found no evidence that B vitamins at typical supplemental doses meaningfully alter CYP enzyme activity. [3] On that basis, a standard multivitamin or a 25 mg B6 tablet alongside 5 mg or 10 mg of lemborexant is not expected to change lemborexant blood levels.

Lemborexant is highly protein-bound in plasma per its labeling, and pyridoxal phosphate (the active circulating form of B6) also binds albumin. [2] A competitive protein-binding interaction is theoretically possible at very high concentrations, but this has not been demonstrated clinically for B6 and lemborexant, and no dose separation is recommended on current evidence.

Pharmacodynamics: Does B6 Add to Dayvigo's Sedative Effect?

Lemborexant produces sedation by blocking orexin receptors. Vitamin B6 has no recognized direct action on orexin, GABA, or histamine receptors, unlike melatonin or valerian, which have their own proposed sedative mechanisms. No additive central nervous system depression from B6 is expected.

B6 is a cofactor in converting tryptophan and 5-hydroxytryptophan into serotonin, which raises a theoretical question about neurotransmitter effects at very high doses. No published clinical trial documents a serotonin-related adverse outcome from combining B6 with a dual orexin receptor antagonist. This remains a theoretical consideration, not a documented one.

Where overlap does matter is in telling side effects apart. Lemborexant's studied adverse effects include somnolence, headache, and dizziness. [8, 9] High-dose B6 neuropathy produces tingling, numbness, and unsteady gait. If a patient on both develops sensory symptoms, distinguishing a B6 effect from a Dayvigo-related effect requires clinical evaluation rather than assumption.

Evidence-Status Interaction Assessment: Vitamin B6 and Lemborexant

This is not a general drug-interaction checker result. It is a claim-by-claim map of what current evidence actually supports for this specific pair, built for a clinician or pharmacist to verify quickly.

Established from FDA labeling and pharmacology

• Lemborexant is metabolized by CYP3A4/CYP3A5; strong or moderate CYP3A4 inhibitors and strong inducers are labeled interactions. [2]
• Vitamin B6 does not appear among the substances flagged in the lemborexant label. [1]
• Chronic high-dose B6 (historically documented at multi-gram daily intakes) causes peripheral sensory neuropathy, independent of co-medication. [7]

Pharmacologically plausible but not demonstrated

• Very high-concentration competition between B6 metabolites and lemborexant for plasma protein binding sites.
• A theoretical serotonin-pathway effect of very high-dose B6 with no documented clinical consequence when combined with an orexin antagonist.

Not established / evidence gap

• No trial of lemborexant enrolled participants specifically to test concurrent high-dose vitamin supplementation, so trial safety data cannot confirm or rule out an interaction. [8, 9]
• The precise lower-dose threshold at which B6 neuropathy risk begins is inconsistent across sources and should not be quoted as a fixed number.
• Whether B6 in the 25 to 100 mg range has any measurable effect on lemborexant pharmacokinetics has not been directly studied.

What a clinician or pharmacist should verify before reassuring a patient

• Total daily B6 intake across every product the patient uses, since multivitamins, B-complex formulas, and standalone tablets stack.
• Whether the patient is also taking a strong CYP3A4 inducer or inhibitor (for example, St. John's Wort, azole antifungals, rifampin), which is the actual documented interaction risk for Dayvigo. [2]
• Whether any new numbness, tingling, or balance change reported by the patient is more consistent with B6 exposure, a Dayvigo side effect, or an unrelated cause.

Who Needs to Be More Careful

The level of caution scales with B6 dose, not with the fact that someone also takes Dayvigo.

Low risk: B6 from a multivitamin, prenatal vitamin, or standalone supplement at roughly 25 mg per day or less, alongside lemborexant 5 mg or 10 mg. No dose adjustment or special monitoring is indicated by current FDA labeling for this combination.

Moderate risk: Sustained B6 intake between roughly 25 and 100 mg per day. This is within the range many clinicians consider acceptable short-term, but a prescriber should know about it, and periodic reassessment is reasonable if it continues for months.

Higher risk: B6 above 100 mg per day taken outside of medical supervision. This applies regardless of co-medication. People who need high-dose B6 for a specific medical reason, such as isoniazid therapy, should have that use coordinated with the clinician managing their sleep medication.

The Isoniazid Connection

Isoniazid, a first-line tuberculosis drug, depletes vitamin B6 by binding pyridoxal phosphate, so clinicians routinely co-prescribe B6, commonly in the 25 to 50 mg per day range, to prevent isoniazid-induced neuropathy. [10] A patient on isoniazid who is also prescribed lemborexant for insomnia may be taking all three agents together. In that situation the B6 dose is medicinal and the TB prescriber is generally aware of it; the interaction concern between B6 and lemborexant remains low, but the full medication list should sit with one coordinating clinician.

What the Lemborexant Trials Show, and What They Don't

Lemborexant's approval rested on two phase 3 trials generally referred to as SUNRISE-1 and SUNRISE-2. The published SUNRISE-1 data compared lemborexant against zolpidem tartrate extended-release and placebo in older adults with insomnia disorder, and reported that lemborexant improved sleep-onset measures compared with placebo. [8] SUNRISE-2 followed adults with insomnia disorder for up to twelve months and also reported improvement in sleep-onset measures versus placebo at multiple timepoints. [9] Readers who want the exact effect sizes, p-values, and enrollment numbers should pull them directly from the published trial reports rather than a secondary summary, since precise trial statistics are easy to misquote.

Neither trial was designed to test concurrent high-dose vitamin supplementation, so they cannot confirm or rule out a B6 interaction; they simply establish lemborexant's general efficacy and side-effect profile, dominated by somnolence, headache, and dizziness. [8, 9] The FDA label's list of clinically significant interactions is limited to CYP3A4 inhibitors and inducers; vitamin B6 is not among them. [2]

Practical Steps If You Take Both

Add up your total B6 intake. Check every product, including multivitamins, B-complex formulas, and prenatal vitamins, since the total daily amount is what matters, not any single product.

Apply the dose threshold. Below about 25 mg per day, no action is generally needed. Between 25 and 100 mg per day, tell your prescribing clinician and plan a check-in if you continue past a few months. Above 100 mg per day, that should already be a supervised decision.

Report new neurological symptoms. New numbness, tingling in the hands or feet, or balance problems should prompt a call to your prescriber. These could reflect B6 exposure, a Dayvigo-related effect, or something unrelated, and distinguishing the cause takes a clinical evaluation, not a guess.

Don't stop Dayvigo abruptly without a plan. Lemborexant is a Schedule IV controlled substance. Stopping any sleep medication abruptly can temporarily worsen sleep; if you want to discontinue it, work out a plan with your prescriber.

Special Populations

Pregnancy. Lemborexant's label describes insufficient human data and fetal effects at high exposures in animal studies. [2] Pregnant patients who take B6 for nausea, a well-supported use, should discuss any additional sleep medication with their obstetric clinician; Dayvigo is not typically a first-line insomnia treatment in pregnancy.

Older adults. Reduced renal clearance can affect both lemborexant and B6 metabolites in older adults, and age-related sensory changes can make early neuropathy symptoms harder to notice. The lower 5 mg lemborexant dose is generally preferred in this group because of next-morning residual effects. [2, 8]

Patients on other CYP3A4-affecting substances. St. John's Wort is a strong CYP3A4 inducer specifically flagged as contraindicated with lemborexant. [2] If a patient combines Dayvigo, B6, and St. John's Wort, the interaction risk comes from the St. John's Wort, not the B6.

What Guideline Bodies Say About This Kind of Decision

The American Academy of Sleep Medicine's 2017 clinical practice guideline for chronic insomnia emphasizes shared decision-making when selecting medications and recommends that clinicians consider all over-the-counter supplements their patients are taking. [11] This approach is especially relevant for lemborexant: because research hasn't yet established clear interaction thresholds, the most prudent safety measure remains a discussion between patient and prescriber about cumulative B6 exposure and whether any new side effects emerge.

Frequently Asked Questions