RisksBy Mayo Clinic staff
Light therapy is generally safe. If side effects occur, they're usually mild and short lasting. They may include:
- Irritability or agitation
- Mania, euphoria, hyperactivity or agitation associated with bipolar disorder
When side effects do occur, they may go away on their own within a few days of starting light therapy. You also may be able to manage side effects by reducing treatment time, moving farther from your light box, taking breaks during long sessions or changing the time of day you use light therapy. Talk to your doctor for additional advice, or if side effects don't go away or get worse.
When to use caution
It's always a good idea to talk to a doctor before starting light therapy, but it's especially important if:
- You have a condition that makes your skin especially sensitive to light, such as systemic lupus erythematosus
- You take medications that increase your sensitivity to sunlight, such as certain antibiotics, anti-inflammatories or the herbal supplement St. John's Wort
- You have an eye condition that makes your eyes vulnerable to light damage
- You have a history of skin cancer
Light therapy boxes should be designed to filter out harmful ultraviolet (UV) light, but some may not filter it all out. This type of light can cause skin and eye damage. Look for a light therapy box that emits as little UV light as possible. If you have concerns about light therapy and your skin, talk to your dermatologist.
Tanning beds: Not an alternative to light therapy
Some people claim that tanning beds help ease seasonal affective disorder symptoms. But this hasn't been proved to work. Visible light, not the UV light released by tanning beds, is used in light therapy. The type of light released by tanning beds can damage your skin and increase your risk of skin cancer.
Caution for bipolar disorder
Light therapy may trigger mania in some people with bipolar disorder. If you have any concerns about how light therapy may be affecting your mood or thoughts, seek help right away.
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