Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Do birth control pills cause weight gain? New research says no

According to research conducted at the Oregon National Primate Research Center at Oregon Health & Science University, the commonly held belief that oral contraceptives cause weight gain appears to be false. The results of the study are published online and will appear in next month's edition of the journal Human Reproduction.

"A simple Google search will reveal that contraceptives and the possibility that they may cause weight gain is a very highly debated topic," said Alison Edelman, M.D., a physician and researcher in the Department of Obstetrics and Gynecology at OHSU and lead author of the study.

"Issues surrounding weight are hard to study in humans, and the research thus far has been insufficient to demonstrate whether or not oral contraceptives cause weight gain or loss. But this is an extremely important question as concern about weight gain is one of the main reasons why women may avoid or discontinue birth control, which in turn places them at greater risk for an unplanned pregnancy."

To conduct their research, scientists and physicians studied a group of rhesus macaque monkeys at the OHSU Oregon National Primate Research Center for almost a year. Rhesus monkeys were used in this study because their reproductive system is nearly identical to humans. However, unlike human studies, more variables can be controlled and measured – such as exact food intake - to provide more meaningful data.

At the beginning of the study, half the animals were obese and half were normal weight. During the eight-month treatment period, animals received doses of oral contraceptives, adjusted to the weight of the animals so that it mimicked dosage in humans. Researchers tracked weight, food intake, activity levels, body fat and lean muscle mass. At the study's conclusion, the normal weight group remained weight stable whereas the obese group lost a significant amount of weight (8.5%) and percent of body fat (12%) due to an increase in basal metabolic rate. No changes were seen in food intake, activity or lean muscle mass for either group.

"This study suggests that worries about weight gain with pill use appear to be based more on fiction than on fact," said Judy Cameron, Ph.D., senior author of the paper and a researcher at the primate center.

"Additionally, there may be a differential affect depending on your starting weight – heavier individuals who keep their diet stable may see a weight loss with pill use. Most likely, the reason why this belief continues to exist is that the weight gain that seems to occur with age is being attributed to these medications. We realize that research in nonhuman primates cannot entirely dismiss the connection between contraceptives and weight gain in humans, but it strongly suggests that women should not be as worried as they previously were."

The research was funded by the Society for Family Planning.


The ONPRC is a registered research institution, inspected regularly by the United States Department of Agriculture. It operates in compliance with the Animal Welfare Act and has an assurance of regulatory compliance on file with the National Institutes of Health. The ONPRC also participates in the voluntary accreditation program overseen by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC).

About OHSU

Oregon Health & Science University is the state's only health and research university, and only academic health center. As Portland's largest employer and the fourth largest in Oregon (excluding government), OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves more than 184,000 patients, and is a conduit for learning for more than 3,900 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to each county in the state.

Jim Newman | EurekAlert!
Further information:

Further reports about: Animal OHSU ONPRC body fat food intake health services muscle mass primate weight gain

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>