Why people try supplements, and the basic caution
Supplements appeal for understandable reasons: they are easy to buy, feel natural and do not require an appointment. But NIMH states plainly that the FDA has not approved any natural products for treating depression, and that research findings on products such as vitamin D and St. John's wort are inconsistent. NIMH advises not using these products without first talking to a health care provider.
It helps to know how supplements are regulated. The FDA explains that it does not have the authority to approve dietary supplements for safety and effectiveness before they are sold; companies are responsible for making sure their products are safe and lawful. The FDA also cautions that "natural" does not mean safe, that supplements can interact with medications, interfere with lab tests or cause problems during surgery, and that a supplement should never replace a prescription medicine.
Quality varies too. NCCIH describes a study of 31 melatonin supplements in which, for most products, the amount of melatonin did not match the label, and 26 percent contained serotonin. Labels such as "standardized" or "certified" do not guarantee consistency, NCCIH adds. Two bottles of the same herb from different brands may not contain the same thing, which makes research results harder to apply to what is on the shelf.
St. John's wort
This is the most studied herb for depression. The National Center for Complementary and Integrative Health (NCCIH) says studies suggest it may help mild or moderate depression and appears more effective than placebo and about as effective as standard antidepressants in that range. It is uncertain whether that holds for severe depression or beyond 12 weeks. NCCIH's research summary for clinicians calls the evidence "far from definitive," since some trials show a benefit and others do not.
The bigger issue is safety. NCCIH says it has been clearly shown that St. John's wort can interact in dangerous, sometimes life-threatening ways with many medicines, weakening some of them. Combined with antidepressants or other drugs that affect serotonin, it can cause serotonin syndrome. It can also cause skin reactions to sunlight, may worsen anxiety in some people, and in rare cases has been linked to psychosis, a particular concern for people with bipolar disorder. NCCIH notes it may be unsafe during pregnancy.
Omega-3 fatty acids
NCCIH describes the evidence on omega-3s for depression as uncertain. Some studies have shown small effects when omega-3s are added to standard treatment, but trials using them on their own are inconclusive, and one large review found that increasing long-chain omega-3s probably has little or no effect on the risk of depression or anxiety symptoms. Omega-3s are generally well tolerated, with side effects such as stomach upset or a fishy aftertaste, but there is some concern about bleeding time, so tell your doctor if you take blood thinners.
SAMe, inositol and vitamin D
- SAMe: NCCIH says current research does not support it for depression; many earlier studies were short, small or used injected forms. People with bipolar disorder should not use it without supervision because it may worsen mania, and it may interact with serotonergic drugs.
- Inositol: NCCIH says the data do not support it for depression.
- Vitamin D: NIMH notes some people report benefit and research is ongoing, but findings are inconsistent. Light Therapy for Seasonal Depression covers its role in winter-pattern depression.
Supplements marketed for anxiety
- Kava: NCCIH notes it may have a small effect on anxiety, but kava products have been linked to rare cases of serious, sometimes fatal liver injury. It should not be combined with alcohol or sedating medicines such as benzodiazepines.
- Chamomile: two NCCIH-supported studies suggest it might help generalized anxiety disorder, but the findings are preliminary.
- Lavender: studies of an oral lavender oil product suggest possible benefit, but NCCIH says limitations, including small study sizes, mean no definite conclusions can be drawn.
- Melatonin: may reduce anxiety before surgery, according to NCCIH, but long-term safety information is lacking, and people with epilepsy or on blood thinners need medical supervision.
NCCIH also reports that some studies found mindfulness-based practices may be as effective as established treatments for managing anxiety symptoms, though more research is needed, and that these psychological and physical approaches generally have good safety records. Mindfulness and Meditation for Anxiety and Depression looks at that evidence.
How to talk with your doctor about supplements
- Bring the bottles or photos of the labels, including doses, to your next appointment.
- Mention everything, even teas, gummies and products a friend recommended.
- Ask whether a supplement could interact with your prescriptions, especially antidepressants, blood thinners and any medicine you depend on to stay well.
- Ask your pharmacist to check for interactions each time you start something new.
- If you have a bad reaction, stop the product and get medical advice; the FDA encourages reporting it.
If you are already on an antidepressant or anti-anxiety medicine, do not swap it for a supplement or add one without checking. Talk with your prescriber before changing anything.
Where therapy fits
Wanting a gentler option often reflects something important: worry about side effects, a wish to feel more in control, or doubts about whether the problem is "bad enough." Those are worth talking through. Psychotherapy is one of the main treatments for both anxiety and depression. Dr. Lehmann does not prescribe medication, but depression therapy and therapy for anxiety with her can be part of a plan you build with your doctor.