What is the time of maximum effect of Adderall (amphetamine and dextroamphetamine) after administration?

From the Guidelines

Adderall typically reaches its maximum effect approximately 2-3 hours after oral administration, with effects on behavior appearing during absorption, beginning 30 minutes after ingestion and lasting 3 to 4 hours. The time of maximum effect can vary depending on several factors, including the formulation of the medication, individual metabolism, body weight, food intake, and stomach pH 1. Immediate-release formulations tend to reach peak levels faster, while extended-release formulations peak later and maintain therapeutic levels longer. The medication's stimulant effects work by increasing dopamine and norepinephrine levels in the brain, improving focus and attention. Some key points to consider:

• The pharmacokinetics of stimulants, including Adderall, are characterized by rapid absorption, low plasma protein binding, and rapid extracellular metabolism 1.
• Effects on behavior appear during absorption, beginning 30 minutes after ingestion and lasting 3 to 4 hours 1.
• Plasma half-life ranges between 3 hours (for MPH) and 11 hours (for DEX) 1.
• Individual factors like metabolism, body weight, food intake, and stomach pH can influence absorption rates and peak effect timing.
• Taking Adderall with food may delay absorption slightly but can reduce stomach discomfort.
• The medication's stimulant effects can lead to the development of tolerance over time, potentially altering the perceived timing of maximum effects 1. It is essential to take Adderall as prescribed, typically in the morning to avoid sleep disruption, and to be aware that the subjective feeling of the medication working may not perfectly align with peak blood levels.

From the FDA Drug Label

Following administration of three 5 mg tablets, average maximal dextroamphetamine plasma concentrations (Cmax) of 36. 6 ng/mL were achieved at approximately 3 hours. Following administration of one 15 mg sustained-release capsule, maximal dextroamphetamine plasma concentrations were obtained approximately 8 hours after dosing.

The time of maximum effect of Adderall (amphetamine and dextroamphetamine) after administration is:

• Approximately 3 hours for the immediate-release tablet
• Approximately 8 hours for the sustained-release capsule 2

From the Research

Time of Maximum Effect of Adderall

The time of maximum effect of Adderall (amphetamine and dextroamphetamine) after administration can be understood through various studies:

• A study published in 2007 3 compared the pharmacokinetics of triple-bead mixed amphetamine salts with a dose-augmentation strategy of mixed amphetamine salts extended release plus mixed amphetamine salts immediate release. The median time to maximum observed plasma concentration (Tmax) values for d-amphetamine and l-amphetamine were 8.0 h for triple-bead MAS and 10.0 h for MAS XR + MAS IR.
• Another study from 2003 4 assessed the pharmacokinetic properties of a single daily dose of Adderall and its extended-release formulation, SLI381 (ADDERALL XR), in pediatric attention-deficit/hyperactivity disorder (ADHD). The time to maximum concentration (Tmax) for SLI381 versus Adderall showed average increases of 3.0 hours for dextroamphetamine and 3.2 hours for levoamphetamine.
• A 1998 study 5 evaluated the time course effects of four doses of Adderall in children with ADHD. Rapid improvements on teacher ratings and math performance were observed by 1.5 hours after administration, and these effects dissipated by the end of the day. The specific pattern of time course effects depended on the dose of Adderall, with the time of peak effects and the duration of action increasing with the dose.

Key Findings

Key findings related to the time of maximum effect of Adderall include:

• The median time to maximum observed plasma concentration (Tmax) values for d-amphetamine and l-amphetamine were 8.0 h for triple-bead MAS and 10.0 h for MAS XR + MAS IR 3.
• The time to maximum concentration (Tmax) for SLI381 versus Adderall showed average increases of 3.0 hours for dextroamphetamine and 3.2 hours for levoamphetamine 4.
• Rapid improvements on teacher ratings and math performance were observed by 1.5 hours after administration of Adderall, with effects dissipating by the end of the day 5.