The short answer
A consistent stimulant interaction between bitter orange and amantadine has not been established. Concentrated products still warrant review, especially if they also contain caffeine or other stimulants.
What this answer covers
Citrus aurantium food versus concentrated p-synephrine-containing or mixed supplements; not equivalent to ephedrine.
- Supplement or preparation
- Citrus aurantium
- Medication ingredient
- amantadine
What the medicine warning covers
Amantadine labeling calls for careful observation with CNS stimulants. That general warning must be matched to the actual constituents of a botanical product; it does not identify every plant preparation as having the same effect.
What the botanical evidence shows
Federal guidance describes inconsistent blood-pressure and heart-rate findings for bitter orange. Serious reports often involve multiple ingredients, and p-synephrine is pharmacologically different from ephedrine.
The exact combination remains unmeasured
No inspected human study quantified this botanical’s added risk with amantadine. Food, concentrated extracts and mixed stimulant products cannot be assigned a common effect size. Intrinsic botanical toxicity is not itself a measured interaction.
Check the complete product
Show the clinician the ingredient list, including caffeine or other stimulants. Seek urgent help for chest pain, fainting, severe agitation or seizures. Do not rely on spacing doses to make a stimulant product safe.
Evidence and practical considerations
Side effects & toxicity
No exact pair study and inconsistent bitter-orange effects; general amantadine stimulant caution cannot establish a consistent Citrus aurantium interaction. Product review remains warranted.
- Exact scope
- Citrus aurantium food versus concentrated p-synephrine-containing or mixed supplements; not equivalent to ephedrine. with Oral amantadine hydrochloride immediate-release capsules; GOCOVRI extended-release considered separately.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed amantadine
May cause insomnia, agitation or somnolence; careful observation with CNS stimulants and other CNS-active medicines. Renal elimination and seizure-history precautions.
How this applies: Exact amantadine RxCUI 620 IN, with stated salt/formulation/route bridge.
No exact supplement-combination incidence or validated protective spacing; salt, route and release form limits apply.
Source 2: Federal supplement guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: People considering the named supplement.
Cardiovascular findings are inconsistent, serious reports often concern mixtures, and tested products vary in amine content.
How this applies: Interpreted for amantadine only within the stated exact preparation and endpoint limits.
No exact amantadine combination trial. Bitter orange p-synephrine differs pharmacologically from ephedrine; findings vary and serious reports often involve mixtures.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Prepared exact amantadine article with formulation-specific evidence and uncertainty. |
Article revision: 775bcf782ba283d7
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?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.