Lithium carbonate is available in a once daily 450 mg extended release tablet. When taken at night it reduces daytime symptoms, such as food cravings. Furthermore, blood work is not mandatory, especially if you know the warning signs of lithium toxicity. i.e. shaking hands. Research has and is showing that lithium is beneficial even in trace amounts, and at lower dosages it has very little side effects. While it's probable that a lowered dose may not be able to control an active episode, a low dose can still prevent relapse. If you can't tolerate a high dose, you can always use it as an adjunct at a lower dose.