Mydayis for adults: long-acting mixed amphetamine salts

Mydayis is a once-daily, extended-release capsule of mixed amphetamine salts whose label says its effects may last up to 16 hours. Its FDA label covers adults, and its adult studies measured effects up to 16 hours after a dose. This page summarizes the label (updated April 30, 2026) and the practical points adults ask about. It is general information; any decision about medication belongs to you and your prescriber.

What it is

Mydayis contains the same four amphetamine salts as Adderall XR and immediate-release Adderall: dextroamphetamine sulfate, amphetamine sulfate, dextroamphetamine saccharate and amphetamine aspartate monohydrate, in a 3 to 1 mix of dextro- to levo-amphetamine. It is a CNS stimulant, and amphetamine is a federal Schedule II controlled substance.

How the capsule works

The difference is in the beads. The label says each capsule holds three types: one immediate-release bead and two different delayed-release beads, one that releases amphetamine at pH 5.5 and another at pH 7.0. In plain terms, the capsule is built to release medication in stages rather than all at once. Adderall XR, by comparison, has two bead types. Extended-release ADHD medications explained covers these designs.

The label tells patients to take Mydayis once daily on waking "because the effects may last up to 16 hours and there is the potential for insomnia." It also advises taking it consistently, either always with food or always without. The capsule can be swallowed whole or opened and the whole contents sprinkled on a spoonful of applesauce, eaten right away without chewing.

Is it approved for adults?

Yes. The label indicates Mydayis for ADHD "in patients 13 years and older," which includes adults. It is not for children 12 and younger: the label explains that younger children had higher drug levels at the same dose and more side effects, mainly insomnia and decreased appetite.

Its effectiveness in adults was established in three short-term studies of people aged 18 to 55. In one four-week placebo-controlled study of 275 adults, both Mydayis groups improved more than placebo on an adult ADHD rating scale. In two crossover studies that used a timed math test of attention, Mydayis separated from placebo starting at 2 or 4 hours after the dose and lasting to 16 hours. The label says studies did not include enough people 65 and older to tell whether they respond differently.

Who it may be discussed for

The label does not say who should get Mydayis over other options. Its long duration is the main difference the label describes, and the label ties that same duration to a risk of insomnia. Whether that trade-off suits your day is a conversation for you and your prescriber. Comparing options side by side is easier with Adderall IR vs XR and Adderall vs Vyvanse.

Not interchangeable with other amphetamine products

The label warns: "To avoid substitution errors and overdosage, do not substitute for other amphetamine products" unit for unit, "because of different amphetamine base compositions and differing pharmacokinetic profiles." If you are switching from Adderall XR or another amphetamine, ask your prescriber how the change will be handled.

The boxed warning

Mydayis carries the boxed warning for CNS stimulants on abuse, misuse and addiction, which the FDA required across the class on May 11, 2023. The label describes a high potential for abuse and misuse that can lead to a substance use disorder, including addiction, with a risk of overdose and death. See misuse and addiction risk.

Common side effects in adults

The label lists the most common adverse reactions in adults with ADHD (at least 5% and at least twice the placebo rate):

• insomnia
• decreased appetite and decreased weight
• dry mouth
• increased heart rate
• anxiety

Serious warnings mirror the rest of the class: risks for people with serious heart disease, increases in blood pressure and heart rate, psychiatric reactions including mania or psychosis, seizures, circulation problems in fingers and toes (including Raynaud's phenomenon), serotonin syndrome, and tics. See ADHD medication, heart health and blood pressure and ADHD medication and sleep.

Who should not take it

• People with known hypersensitivity to amphetamine or other ingredients.
• People taking an MAOI, or within 14 days of stopping one, including linezolid or intravenous methylene blue.

The label also caps the amount for severe kidney impairment and does not recommend Mydayis for people with end-stage renal disease.

Interactions to mention

The interaction list follows other amphetamines: MAOIs (contraindicated), serotonergic drugs and CYP2D6 inhibitors (serotonin syndrome risk), alkalinizing agents such as some antacids (raise amphetamine levels), acidifying agents (lower them), tricyclic antidepressants and proton pump inhibitors. Bring your full list, including over-the-counter products. Details are in ADHD medication drug interactions.

Pregnancy and breastfeeding

The label says available data on amphetamine in pregnancy are not sufficient to inform a drug-associated risk for major birth defects and miscarriage, and that premature delivery and low birth weight have been seen in infants of mothers dependent on amphetamines. It lists a pregnancy registry. Because of possible serious reactions in nursing infants, it advises that breastfeeding is not recommended during treatment. NIH LactMed summarizes the evidence on amphetamine in breast milk, including expert views that differ from manufacturer advice. See ADHD in pregnancy and postpartum.

Generic availability and supply

Generics exist. Drugs@FDA lists a Teva extended-release capsule (ANDA 210876, approved January 31, 2022) with the same therapeutic equivalence code as Mydayis (AB2), and the Orange Book data dated October 9, 2026 also list AB2 generics from SpecGx (approved August 31, 2023) and Sun (approved September 27, 2023). The Teva DailyMed label carries the same "13 years and older" indication. Whether a pharmacy stocks it, and what it costs on your plan, varies, so ask your pharmacy and insurer. As of October 19, 2026, the FDA drug shortage database did not list these extended-release capsules as a current shortage, though it did list immediate-release mixed amphetamine salts tablets. See ADHD medication cost in New York and generic ADHD medications.

New York and New Jersey rules

Federal rules bar refills of Schedule II prescriptions; a prescriber may issue multiple dated prescriptions covering up to 90 days.

• New York: an I-STOP registry check before prescribing, plus state supply and timing rules. See New York's rules for ADHD stimulant prescriptions.
• New Jersey: under P.L.2026, c.40 (effective July 8, 2026), adults located in New Jersey who start a Schedule II stimulant by telehealth need an in-person visit within 30 days, a contact every three months and an in-person visit at least once a year. State rules also call for a history, exam, NJPMP check and treatment plan before a controlled substance is started. See New Jersey's rules.
• Federal telehealth: as of October 2026, DEA telemedicine flexibilities run through December 31, 2026.

Dr. Shershow is a psychiatrist licensed in New York and New Jersey who provides medication management when medication is appropriate. The office can explain how visits work for patients located in New Jersey.

Questions to ask your prescriber

• Do I need coverage this long, or would a shorter product protect my sleep?
• Should I take it with food or without, and how do I keep that consistent?
• If I switch from Adderall XR, how will the change be handled?
• Is the generic available at my pharmacy?

See also questions to ask before starting ADHD medication. Never start, stop or change a medication without your prescriber.