This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Effect of Bright Light on Sex Hormones and Ovulation in Humans

This study has been completed.
Information provided by:
Russian Academy of Medical Sciences Identifier:
First received: May 17, 2006
Last updated: October 18, 2009
Last verified: October 2009
The study investigated whether bright artificial light may influence menstrual cycle and ovulation conclusively, and what underlying hormonal changes for this effect are.

Condition Intervention
Anovulation Procedure: Light therapy

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Basic Science

Further study details as provided by Russian Academy of Medical Sciences:

Enrollment: 27
Study Start Date: September 2003
Study Completion Date: April 2006
Detailed Description:
Several studies have shown a shortening of the menstrual cycle following light therapy in women with abnormally long menstrual cycles or with winter depression, which suggests that bright light may influence sex hormones and ovulation. The study was designed to investigate this possibility. Twenty-two women with slightly lengthened menstrual cycles and without clinically evident endocrine abnormalities completed a study lasting for two menstrual cycles separated by an off-protocol episode of at least 1 menstrual cycle. Bright light therapy was administered for a week at home during one experimental cycle, and dim light during another cycle (placebo-controlled, crossover, counter-balanced order). Daytime blood sampling and ultrasound scan were performed before and after a week of light therapy, on the ~7th and 14th days after menstruation onset. Ultrasound examination was repeated further to document ovulation. Serum was assayed for thyroid-stimulating hormone, prolactin, luteinizing hormone, follicle-stimulating hormone, and estradiol. The preliminary results were reported at the SLTBR meeting in June, 2005.

Ages Eligible for Study:   19 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 19-40 years
  • Mean menstrual cycle 28-38 days
  • Good general health
  • Generally normal sleep-wake regimen
  • Motivated for free participation

Exclusion Criteria:

  • Low cooperation
  • Medications known to interfere with hormone release
  • Clinically evident endocrine abnormalities including the signs of
  • Hyperandrogenism
  • Travel over several time zones during two months prior the study
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00327366

Sponsors and Collaborators
Russian Academy of Medical Sciences
Principal Investigator: Konstantin V. Danilenko, MD Institute of Internal Medicine SB RAMS
  More Information

Responsible Party: Outside In Identifier: NCT00327366     History of Changes
Other Study ID Numbers: M-s3
Study First Received: May 17, 2006
Last Updated: October 18, 2009

Keywords provided by Russian Academy of Medical Sciences:
Menstrual Cycle
Light Therapy
Sex Hormones

Additional relevant MeSH terms:
Ovarian Diseases
Adnexal Diseases
Genital Diseases, Female
Gonadal Disorders
Endocrine System Diseases processed this record on August 22, 2017