The short answer
Parsley has not been shown to raise lithium citrate absorption or levels. A small human parsley-tea study found no significant change in urine volume or measured electrolytes, which limits a blanket diuretic explanation.
What this answer covers
Petroselinum crispum species entry. Parsley leaf tea is not seed oil, a concentrated extract or a multi-herb product; abstract-level species characterization is incomplete.
- Supplement or preparation
- Petroselinum crispum
- Medication ingredient
- lithium citrate
A human study found no clear urinary effect
Twenty healthy volunteers compared parsley leaf tea with water in a crossover study. Urine volume, pH, sodium, potassium and other measured solutes did not differ significantly. The study did not involve lithium recipients.
What that result means
The null findings weaken the assumption that parsley tea necessarily produces clinically important diuresis or sodium loss. They do not prove that every parsley preparation is safe with lithium or exclude effects from a different dose or extract.
Lithium levels depend on kidney handling
Sodium depletion and dehydration can raise lithium levels, but that general warning does not show that parsley increases absorption. The available evidence cannot justify treating ordinary food exposure and concentrated supplements as identical.
Review concentrated products
Lithium levels are sensitive to dehydration and changes in salt balance. Tell the treating team about significant diarrhea, sweating, poor fluid intake or a new urinary product. Do not alter the lithium dose yourself. A fixed gap between doses has not been shown to prevent changes in kidney clearance.
Evidence and practical considerations
Absorption & effectiveness
No qualifying exact-pair evidence establishes increased absorption or levels. The small leaf-tea study found no significant urinary effect and does not cover all preparations.
- Exact scope
- Petroselinum crispum species entry. Parsley leaf tea is not seed oil, a concentrated extract or a multi-herb product; abstract-level species characterization is incomplete. with Lithium citrate oral solution, exact RxCUI 52105; current NLM IN. Carbonate evidence is indirect through lithium ion where stated.
- Medication form and route
- oral lithium citrate; oral supplement
What remains uncertain
- Source-specific identity, preparation and endpoint limitations apply; no unstudied dose conversion.
Factors that may matter: Exact preparation; Amount and changes in use; Kidney function; Other medicines.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed lithium oral solution.
Lithium is eliminated mainly in urine. Sodium depletion can reduce clearance and raise levels; xanthines and alkalinizing agents can increase urinary excretion and lower levels. Serotonergic agents, explicitly including St John’s wort, increase serotonin-syndrome risk.
How this applies: Only the stated identity, preparation, route and endpoints; limitations also govern extrapolation to the exact pair.
Lithium active-moiety bridge supports renal pharmacology across salts but not identical formulation kinetics, dose equivalence for self-use or quantified effects of every herb.
Source 2: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 20 healthy volunteers.
No significant difference in urine volume, pH or measured urinary solutes, including sodium and potassium.
How this applies: Only the stated identity, preparation, route and endpoints; limitations also govern extrapolation to the exact pair.
Abstract does not adequately characterize botanical species or extract composition. No lithium recipients; tea results cannot establish effects of seed oil or concentrated extracts.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Prepared exact-pair article preserving salt, botanical and evidence limitations. | |
| Research summary published |
Article revision: 2d027af7f400ee90
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.