The short answer
Sodium acid phosphate can reduce amphetamine sulfate's effect by increasing its removal in urine. The record gives no universal product dose or dose-spacing interval.
What this answer covers
Applies to sodium phosphate, monobasic, identified in the source as sodium acid phosphate, with oral amphetamine sulfate during meaningful urinary acidification.
- Supplement or preparation
- Sodium phosphate, monobasic
- Medication ingredient
- amphetamine sulfate
Evidence and practical considerations
Absorption & effectiveness
The exact label names sodium acid phosphate as a urinary acidifying agent that increases excretion and decreases efficacy.
- Exact scope
- sodium acid phosphate with amphetamine sulfate
- Medication form and route
- oral amphetamine sulfate
- Timing or duration
- During clinically meaningful acidifying co-exposure.
What remains uncertain
Factors that may matter: exact sodium acid phosphate preparation and dose; renal function; baseline amphetamine response.
Read the supporting source summaries
Source 1: current United States prescribing information
dailymed.nlm.nih.gov · Source check Jul 25, 2026
Population: Patients prescribed oral amphetamine sulfate.
Sodium acid phosphate is named among urinary acidifying agents that increase ionized amphetamine, increase urinary excretion, and decrease efficacy.
Label describes agent categories and does not quantify a universal supplement dose, timing interval, or absolute risk.
Research assessment: · Open full citations ↗
Timing & monitoring
The exact label names sodium acid phosphate as reducing efficacy through increased urinary excretion.
- Exact scope
- sodium acid phosphate with amphetamine sulfate
- Medication form and route
- oral amphetamine sulfate
- Timing or duration
- During acidifying product co-use.
What remains uncertain
- No universal timing interval was established.
Factors that may matter: exact preparation and dose; renal function; clinical response.
Read the supporting source summaries
Source 1: current United States prescribing information
dailymed.nlm.nih.gov · Source check Jul 25, 2026
Population: Patients prescribed oral amphetamine sulfate.
Sodium acid phosphate is named among urinary acidifying agents that decrease efficacy.
Label describes agent categories and does not quantify a universal supplement dose, timing interval, or absolute risk.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Research summary published |
Article revision: 7b0a1d592cd0e540
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
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Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.