Do Sun Lamps Actually Work? Seasonal Affective Disorder (SAD)

Medically Reviewed on 11/23/2021
Do Sun Lamps Actually Work
Sun lamps are used to treat conditions caused by lack of sunlight exposure and may be effective in easing symptoms of seasonal affective disorder (SAD)

Sun lamps, also called light therapy boxes or seasonal affective disorder (SAD) lamps, emit ultraviolet rays that mimic sunlight and are used to treat conditions caused by lack of sunlight exposure. Conditions that can potentially be treated with a sunlamp include:

The efficacy of sun lamps in easing symptoms of seasonal affective disorder has been well documented. However, the FDA does not regulate the use of sun lamps. 

There are many varieties of sun lamps available, each with different intensity of light. Consult a medical professional about which type is suitable for your condition.

How did the use of sun lamps start?

During World War I, physicians noted that wounds healed faster in patients who were exposed to sunlight. As starvation and malnutrition hit the population, children developed rickets, caused by poor diet and lack of sunlight.

Kurt Huldschinsky, a Berlin physician, discovered that ultraviolet light from lamps effectively treated rickets. Gradually, the use of sun lamps was extended to treat skin disorders, burns, sleep disorders, neonatal jaundice, and even some psychiatric disorders.

How do sun lamps work?

The sun lamp should be placed at a good distance from where a person works or sits. They need to have their eyes open, but should not stare at the lamp because the light may damage the eyes. 

An effective sun lamp should have a minimum intensity of 2,500 lux. However, the most prescribed sun lamp is of 10,000 lux intensity, which is to be used in the morning. Sun lamps are mostly used in the fall because, during this season, the intensity of natural sunlight is low.

Light therapy depends on what it is being used for, and accordingly, the session is either done in the morning or evening. To treat vitamin D deficiency, light therapy is given early in the morning for 15 minutes. To treat seasonal affective disorder, light therapy is administered for a couple of hours in the morning, evening, and night. The time and intensity of the light used is prescribed by a doctor depending on the condition of the patient.

The exact mechanism behind the therapeutic benefits of sub lamps is not completely understood. Exposure to light may affect levels of hormones, such as melatonin and serotonin, which regulate mood and sleep. Vitamin D production and a decrease in blood pressure are seen with exposure to natural ultraviolet rays in sunlight, so it is believed that ultraviolet rays from sun lamps may have the same effect on the body.

What are the risks associated with the use of sun lamps?

While light therapy is generally safe, exposure to ultraviolet rays come with risks:

  • Patients who are on medications that cause photosensitivity, such as hormonal medications, acne medications, and skin peels, could be at risk of damaging their skin or eyes.
  • Patients with bipolar disorder may have an increased risk of developing manic symptoms.
  • Patients who are sensitive to light may be at risk of developing skin cancers.
  • During the initial stages, the therapy may cause nausea, headache, and eye strain, although these symptoms typically resolve after a week.
  • The FDA has issued a warning that sunlamp products should not be used on people younger than 18 because of the associated risks of eye damage, premature skin aging, and cancers.


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Medically Reviewed on 11/23/2021
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Chandra P, Wolfenden LL, Ziegler TR, et al. Treatment of vitamin D deficiency with UV light in patients with malabsorption syndromes: a case series. Photodermatol Photoimmunol Photomed. 2007;23(5):179-185.

University of Michigan Health. Seasonal Affective Disorder: Using Light Therapy.

Cleveland Clinic. Will a SAD Sun Lamp Actually Make You Happy?

Miller MC. Seasonal Affective Disorder: bring on the light. Harvard Health Publishing.