Five Herbal Products That May Not Help Depression
Published on 22 January 2014

In an effort to treat depression, many patients try an herbal product that is available over-the-counter. With the dizzying number of choices, I took a look at the research behind nine herbal products and found there is a wide range of effectiveness when it comes to treating depression.
In general, there is no relationship between price and quality in these types of products. Research has also found:
- Potency is sometimes different than what is advertised on the label
- Ingredients are sometimes missing from the label
- Ingredients can be contaminated
- Ingredients can be altered
Inositol- Possibly Ineffective. Not yet recommended for use with depression.
What is it? A naturally occurring compound that is similar to glucose. It works differently than other antidepressants by relaying messages from brain pleasure centers.
Good: Preliminary evidence shows 12 grams a day for four weeks might help depression.
Bad: Any potential effect stops quickly after a patient ends treatment.
Melatonin- Likely Ineffective.
What is it? A naturally occurring hormone that helps regulate sleep and alert cycles in the body.
Good: Some research suggests it may decrease winter depression in patients with seasonal affective disorder (SAD).
Bad: Studies point to a concern that it may worsen symptoms of depression.
Fish Oil- Insufficient Evidence:
What is it? Source of two omega-3 fatty acids which might help brain function.
Good: Some evidence suggests 9.6 grams a day might help prescription antidepressant medication.
Bad: More than three grams a day can be harmful to patients taking anticoagulation medication, known as blood thinners.
L-Tryptophan- Insufficient Evidence:
What is it? A chemical that can be turned into serotonin under the right conditions. Serotonin levels are usually low in patients diagnosed with depression.
Good: Potentially helpful with depression.
Bad: Effective dosage information has yet to be determined, and it’s also not known if it is safe to use long-term. In 1989, 37 died and more than 1,500 patients were diagnosed with the incurable neurological condition Eosinophilia–myalgia syndrome. Most of the cases were traced back to a single L-Tryptophan manufacturer.
Gingko- Insufficient Evidence:
What is it? Extract of the gingko tree.
Good: May be effective in assisting memory.
Bad: No reliable evidence to treat depression. Recent evidence also suggests it is not effective in treating the sexual side effects of selective serotonin reuptake inhibitors (SSRIs), a class of medication used to treat depression.
In my next post, we’ll examine four herbal supplements that may help depression.
-Laura Challen, Pharm.D., BCPS, MBA, assistant professor of pharmacy practice
Update: Part two has been published here.
Photo Credit: "vitamin supplement tablets" by Ragesoss - Own work. Licensed under CC BY-SA 3.0
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