Lithium: What It Is, How It Works, and How to Use It Safely

If you or someone you know has been prescribed lithium, you probably have questions about why this simple salt matters so much. Lithium is a mood‑stabilizing mineral that’s been used for decades to treat bipolar disorder and prevent extreme mood swings. It isn’t an antidepressant or a sedative; it helps smooth out the highs and lows so daily life feels more balanced.

Getting the Dose Right

The first thing to know is that lithium dosing isn’t one‑size‑fits‑all. Doctors start with a low dose, often 300 mg to 600 mg a day, and adjust based on blood‑level tests. The goal is to keep the blood concentration between 0.6 and 1.2 milliequivalents per liter (mEq/L). Too low and you won’t get the mood‑stabilizing effect; too high and you risk toxicity.

Take lithium exactly as your doctor tells you—usually with food and a full glass of water. Skipping doses or taking extra because you feel “off” can throw off the blood level and cause side effects. If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose; then just skip the missed one.

Because lithium is cleared by the kidneys, staying hydrated is key. Aim for about 2‑3 liters of water a day, unless your doctor says otherwise. Dehydration can raise lithium levels quickly, leading to nausea, tremor, or worse.

Common Side Effects and What to Watch For

Most people feel fine after the first few weeks, but some notice mild issues like increased thirst, more trips to the bathroom, or a slight hand tremor. These often settle as your body gets used to the medication.

Serious side effects are rare but need immediate attention. Watch for severe tremors, confusion, slurred speech, or a rapid heartbeat—these could signal lithium toxicity. If you have any of these, call your doctor or go to the ER right away.

Long‑term use can affect thyroid and kidney function. Your doctor will likely check thyroid hormone levels and kidney labs every 6‑12 months. If you develop hypothyroidism (low thyroid), a simple hormone replacement can keep you feeling normal while staying on lithium.

Here are a few practical tips to make lithium work for you:

• Schedule regular blood tests—usually every 4‑6 weeks when you start, then every few months.
• Keep a medication diary. Note the dose, time, any side effects, and how you feel day‑to‑day.
• Avoid over‑the‑counter NSAIDs (like ibuprofen) unless your doctor approves; they can raise lithium levels.
• Don’t mix lithium with salty foods or high‑sodium diets. Salt changes how your kidneys handle the drug.

Finally, be open with your healthcare team. If you feel mood changes, weight gain, or new symptoms, let them know. Adjusting the dose or adding a supplement (like thyroid medication) can keep you steady without sacrificing safety.

Lithium can be a powerful ally for mood stability when used correctly. With regular monitoring, proper hydration, and clear communication with your doctor, you can enjoy the benefits while minimizing risks.