About one in every four people experience weight gain from taking the mood stabilizer lithium, as reported by Acta Psychiatrica Scandinavica. Based on the research conducted on this issue, the average weight gain that people who take lithium experience is usually between ten and twenty six pounds. Some studies show that people taking lithium are likely to gain approximately 8% of their total body weight.

For those who experience weight gain while taking lithium, it is recommend that they limit the consumption of high calorie food and drinks. Lithium is notorious for making people thirsty. It is therefore recommended that people on lithium drink a good deal of water or other low-calorie liquids to help satiate their thirst and avoid excess weight gain. High calorie drinks should be avoided.

There are a number of theories as to why lithium causes some people to gain weight. Causes include increased appetite and thirst, sodium retention and changes in metabolism. Swelling and bloating can also occur when more salt and water is retained. Lithium is also known to cause fatigue in some, which can lead to less physical exercise and a more sedentary lifestyle.

Patients should always consult with their physicians about how they’re tolerating their medications. Physicians can help patients develop a strategy to deal with any weight gain associated with lithium or they might be able to identify an alternative medication altogether.

For example, Lamictal has been shown to be less likely to cause weight gain than other mood stabilizers in clinical trials. Indeed, under five percent of patients on Lamictal gained weight. 
But Lamictal is also not indicated for treating acute manic episodes: it’s more of a maintenance drug where as lithium is something that can be used for both manic and depressive episodes as well as both acute and maintenance treatment.

Used by many as a nutritional supplement, Lithium orotate is often taken in micro doses much like selenium or zinc. People use lithium supplements for alcohol use disorder, Alzheimer disease and certain other conditions, but to date there is not strong scientific evidence to support its efficacy. Lithium orotate is not the same substance as the medication lithium used to treat bipolar disorder.