Lithium works in a narrow window, which is why the blood tests are not optional
Toxicity can happen at doses close to the ones that treat you.
Top of the evidence hierarchy, independently funded. how we score evidence
Lithium's boxed warning says something unusual for a psychiatric medication. Toxicity is closely tied to the concentration in your blood, and it can occur at doses close to therapeutic ones. The label instructs that facilities for prompt and accurate lithium measurement must be available before treatment is even started.
That is why the blood draws exist. They are not administrative. The label directs a level drawn 12 hours after a dose, repeated regularly until you are stable, targeting roughly 0.8 to 1.2 mEq/L for an acute episode and 0.8 to 1 for maintenance.
Things that shift your level without your dose changing: dehydration, a stomach bug, heavy sweating, a low-salt diet, and several common drugs including ibuprofen and some blood-pressure medications.
Worth asking
How often am I getting levels checked, what is my target range, and what should I do about my lithium if I get a vomiting illness or become dehydrated.
What it is FDA approved for
Read off the label. Trial duration and approval year are shown only where they were recorded — never inferred.
- Treatment of manic episodes of bipolar disorder
- Maintenance treatment of bipolar disorder
Source
Lithium carbonate prescribing information — Boxed Warning: Lithium Toxicity — U.S. Food and Drug Administration (approved labelling)
Regulator or national health body
How this was scored
- Study design
- Regulatory safety determination
- Funding
- No external funding
- Published in
- Regulator or national health body
- Sample size
- not recorded
- Preregistered
- No
- Conflicts disclosed
- Yes
- Independent of proponent
- Yes
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 5, 2026. Last verified August 19, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "gold standard". Top of the evidence hierarchy, independently funded. It scores 86 out of 100 on our published rubric. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Lithium carbonate prescribing information — Boxed Warning: Lithium Toxicity — U.S. Food and Drug Administration (approved labelling). Published in: Regulator or national health body. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Regulatory safety determination. Funding: No external funding. The researchers were independent of whoever benefits from the result. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is lithium (Lithobid, Eskalith) FDA approved?
Yes — FDA approved for Treatment of manic episodes of bipolar disorder, Maintenance treatment of bipolar disorder. Approval is for a specific indication, not for everything the drug is prescribed for.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.