Reyvow (lasmiditan) treats acute migraine attacks by activating a specific serotonin receptor in the nervous system called 5-HT1F. This receptor plays a key role in pain signaling along the trigeminal nerve, the main pathway responsible for migraine pain. Unlike older migraine medications like triptans, Reyvow does not constrict blood vessels, which makes it a fundamentally different type of treatment.
How Reyvow Stops Migraine Pain
During a migraine, the trigeminal nerve becomes overactive and releases a protein called CGRP (calcitonin gene-related peptide) along with the neurotransmitter glutamate. These chemical signals trigger inflammation and intense pain in and around the head. Reyvow works by binding to 5-HT1F receptors on nerve cells in this pathway, which blocks the release of both CGRP and glutamate. By cutting off these pain signals, the drug can prevent and potentially reverse the process of central sensitization, where the brain becomes increasingly responsive to pain during a migraine attack.
Reyvow crosses the blood-brain barrier easily, meaning it reaches the brain itself rather than acting only on nerves outside it. This central nervous system penetration is likely why it works well against migraine pain, but it’s also the reason behind its most notable side effects.
Why It Differs From Triptans
Triptans, the most commonly prescribed acute migraine medications, work primarily by activating 5-HT1B and 5-HT1D receptors. The 5-HT1B receptor is found on blood vessel walls and causes them to constrict when activated. That vasoconstriction helps relieve migraine pain but creates a serious limitation: people with heart disease, uncontrolled high blood pressure, or a history of stroke generally cannot take triptans safely.
Reyvow has very low affinity for 5-HT1B receptors. The 5-HT1F receptor it targets isn’t found in the smooth muscle or lining of blood vessels in the brain at all, so it has no effect on vascular tone. This means Reyvow doesn’t carry the same cardiovascular restrictions that triptans do, filling an important gap for migraine patients who have heart-related risk factors.
Dosing and How to Take It
Reyvow comes in three dose strengths: 50 mg, 100 mg, and 200 mg tablets taken by mouth when a migraine starts. Only one dose is allowed in a 24-hour period. There is no option to take a second dose if the first one doesn’t fully work, which is a notable difference from triptans, where a second dose is often permitted after two hours.
Common Side Effects
Because Reyvow penetrates the brain so readily, its side effects are predominantly neurological. In clinical trials and real-world studies, nearly half of patients experience at least one side effect. Dizziness is the most common, reported by roughly 15% of patients in the large SAMURAI and SPARTAN clinical trials and up to 29% in some real-world populations. Sleepiness affects about 10% of patients, and nausea around 8%. Tingling or numbness (paresthesia) also occurs, though rates vary across different populations.
These side effects tend to be most pronounced in the first couple of hours after taking the medication and are dose-dependent, meaning higher doses produce more frequent and more intense effects.
The 8-Hour Driving Restriction
Reyvow carries an FDA-mandated warning that you should not drive or operate heavy machinery for at least 8 hours after taking it. This is not a soft suggestion. In formal driving studies, all three doses (50 mg, 100 mg, and 200 mg) significantly impaired the ability to drive. At 90 minutes after a dose, impairment was clear and dose-dependent. Even at the 8-hour mark, patients reported more sleepiness compared to placebo.
Importantly, the FDA notes that patients may not be able to accurately judge their own level of impairment after taking Reyvow. Feeling alert enough to drive doesn’t necessarily mean you are. The labeling is direct: if you cannot commit to waiting at least 8 hours before driving, you should not take the medication. This restriction makes Reyvow less practical for migraines that hit during the workday or when you need to be somewhere, and it’s worth factoring into your planning.
Why It’s a Controlled Substance
Reyvow is classified as a Schedule V controlled substance, the lowest level of DEA scheduling. This classification exists because the drug can produce euphoria at higher doses. In a study comparing lasmiditan to a common anti-anxiety medication (alprazolam), euphoric mood was reported by about 25% of participants at the 100 mg dose, 49% at 200 mg, and 46% at the supratherapeutic 400 mg dose. Sleepiness also increased with dose, affecting over half of participants at the highest level tested.
That said, the overall abuse potential was judged to be low, significantly lower than alprazolam at every dose tested. The Schedule V classification reflects this: it signals that some caution is warranted, but the risk is minimal compared to most controlled substances. In practical terms, it means your prescription may face slightly more oversight than a standard migraine medication, though far less than something like a Schedule II or III drug.