Light Therapy for PMS and PMDD

Also known as late luteal phase dysphoric disorder, Premenstrual Syndrome, or PMS, afflicts up to 40% of women during their reproductive years. For the majority of sufferers, it’s a minor inconvenience, but for some it can be debilitating.

Up to 10% of women report that PMS symptoms have an adverse effect on their lives and particularly, their relationships. PMS sufferers who have at least five PMS symptoms, including a mood disorder, may be diagnosed with Premenstrual Dysphoric Disorder (PMDD), which is a far more serious condition. Common PMS symptoms include:


  • Anxiety
  • Irritability
  • Depression
  • Heachache
  • Weight gain
  • Wildly fluctuating mood
  • A worsening of the symptoms of other conditions such as asthma

Some women also experience positive PMS symptoms, such as increased creativity, energy, industriousness, and sexual interest.

Conventional PMS treatments for negative symptoms may include medication, lifestyle changes, or both. Common treatments include:


  • Psychosocial ‚Äì reassurance, support, and education about the disorder
  • Obtaining sufficient sleep
  • Getting more exercise
  • Ovulation suppressants
  • Medications to decrease fluid retention
  • Antidepressants and/or anti-anxiety medications
  • Non-prescription pain killers such as acetaminophen and ibuprofen for joint and muscle pain

Light Therapy

Light therapy is administered via a light box or smaller portable “light book” that emits 10,000 lux light. Light therapy users sit 12-24 inches away from the light source (distance may vary based on the device used) with their eyes open. The light is used for 30 minutes per day on average, though duration may be adjusted downward or upward as needed because individual responses to bright light vary.

There is evidence that light therapy may provide benefits for certain PMS sufferers who experience negative symptoms. Approximately 25% of PMS sufferers say that their symptoms worsen during certain times of the year, particularly the darker fall and winter months. This is a similar pattern to that of Seasonal Affective Disorder (S.A.D.), which is characterized by a winter depression that lifts during the lighter months of spring and summer. Also, many PMS sufferers manifest circadian rhythm abnormalities similar to those who are depressed.

Light therapy, which is effective in treating S.A.D. and non-seasonal depression, also shows promise for treating PMS and PMDD symptoms. Overall, there have been only a few controlled studies of light therapy for PMS or the more severe PMDD, but many subjects in these trials achieved a significant reduction in symptoms.


Side effects of light therapy, if they occur, tend to be mild. They may include headache, eyestrain, or jitteriness.

Given that it is relatively safe for most people, light therapy may be worth exploring if alternative treatments for PMS depression and other symptoms don’t work. However, consulting a doctor before beginning light therapy is recommended.