What to Expect When Starting Lithium
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting, stopping, or changing any medication. Using this site does not create a doctor-patient relationship.
Drug information changes as the FDA updates labeling, and we cannot guarantee it is complete or current. Verify critical details with your pharmacist or physician.
Emergencies: If you think you may have a medical emergency, call 911 immediately. For a suspected overdose, call Poison Control at 1-800-222-1222. Report side effects to the FDA MedWatch program at fda.gov/medwatch or 1-800-FDA-1088.
See our Terms of Use and Editorial Policy.
Introduction
Lithium is a mood-stabilizing medication used primarily to treat and prevent manic and depressive episodes in bipolar disorder. It requires careful blood level monitoring because the therapeutic window is narrow — levels too low may not be effective, while levels too high can cause serious toxicity. Most patients need 1-2 weeks to reach stable blood levels and several weeks to experience the full mood-stabilizing benefit.
Week-by-week timeline
Initiating Therapy
Lithium is started at a low dose, typically 300 mg two to three times daily, and gradually increased. Common early side effects include fine hand tremor, thirst, increased urination, nausea, and mild diarrhea. Take with food to reduce GI upset.
First Blood Level Check
Blood levels are checked 12 hours after the last dose (target 0.6-1.2 mEq/L for maintenance). Dose is adjusted based on results. Side effects usually begin to improve. Mild cognitive slowing may be noticed.
Reaching Stable Levels
Lithium levels stabilize. You may notice improved mood regulation and reduced cycling between highs and lows. Mild tremor and thirst may persist but are manageable. Thyroid and kidney baseline labs are obtained.
Mood Stabilization
The full mood-stabilizing effect becomes evident. Manic and depressive episodes are less frequent. Blood levels are checked every 1-3 months once stable. Weight gain of 2-5 kg is possible.
Long-Term Monitoring
Monitoring every 6-12 months: serum lithium level, kidney function (creatinine, eGFR), thyroid function (TSH), and calcium. Lithium is often a lifelong medication for bipolar disorder.
When to call your doctor
Contact your healthcare provider if you experience:
- Signs of lithium toxicity: coarse tremor, confusion, slurred speech, muscle twitching — seek emergency care
- Severe nausea, vomiting, or diarrhea causing dehydration (raises lithium to dangerous levels)
- Significant mood changes including new depression or suicidal thoughts
- Signs of hypothyroidism: fatigue, cold intolerance, unexplained weight gain
- Reduced urination or leg swelling (kidney problems)
- New or worsening rash
Tips for getting started
Maintain consistent fluid and sodium intake — dehydration or a low-salt diet can raise lithium to toxic levels. Avoid NSAIDs (ibuprofen, naproxen) as they raise lithium levels significantly. Never skip doses or double up. Carry a medical ID noting lithium use. Keep all blood test appointments — they are essential for safe use.
Frequently asked questions
More about Lithium
References
- [Regulatory] FDA Prescribing Information for Lithium Carbonate https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/018099s044lbl.pdf Accessed 2026-03-01.
- [Regulatory] NIH MedlinePlus: Lithium https://medlineplus.gov/druginfo/meds/a681039.html Accessed 2026-03-01.
- [Clinical] American Psychiatric Association Practice Guideline: Bipolar Disorder https://psychiatryonline.org/doi/book/10.1176/appi.books.9780890423837 Accessed 2026-03-01.
Written and fact-checked by PrescriptionDrugs.org Editorial Team
Last updated: