- Weight Loss -

Worth Its Weight? The Debate About Birth Control and Weight Gain

If you use a hormonal method of birth control, you may gain weight. Then again, you may not. Your doctor can’t tell you. In fact, you could be the best expert on this weighty matter.

When women get together – around the office cooler, after a yoga class or in the bleachers at a kid’s Little League game – the topic of weight almost invariably comes up. From that point, the conversation may swerve from diet and fitness to the trials of postpartum weight loss. Or, depending on who’s talking, it may take a hard right toward another topic: hormonal methods of birth control.

Someone almost always has a horror story to tell: a friend who billowed from a size 4 to a size 14 after going on the Pill or a sister who, just weeks after receiving her first Depo-Provera injection, could no longer fit into her wedding dress for her long-anticipated walk down the aisle.

Katrina Hannemann is one of those stories. Five years ago, when she was an 18-year-old freshman at Concordia College in Minnesota, Hannemann watched helplessly as her weight spiraled out of control within months of starting Depo-Provera injections. The 5-foot-6 student went from a lithe 125 pounds to an elastic-stretching 175 pounds within just six months. By the time she stopped taking Depo-Provera, almost two years later, her weight had peaked at 185 pounds. Only recently, more than a year after ending the hormone injections, has Hannemann begun to see her weight drop – and her pants size shrink.

Kimberly Bobby, a law student at the University of Denver, tells a similar, although not quite as dramatic, tale. Within two months of going on birth control pills last fall, she gained 7 pounds, which was slightly more than 5 percent of her total weight. The extra poundage came as a surprise to Bobby because she had previously taken the Pill for years at a time without any noticeable change in her body weight or size.

“It wasn’t the most comforting thing to be putting on weight during law finals,” she says with a laugh. “I was running and had been losing some weight, and then suddenly I noticed that I was experiencing a lot of water retention and that my breasts were swelling. I really noticed it around my middle. My pants started getting tight.”

With real-life stories like these in circulation, it’s no wonder that four out of 10 women who responded to a recent national survey cited weight gain as a reason to avoid the Pill.

No Way to Predict

There are fears, there are facts, and then there is the murky, confusing area in between. What most women want to know is, are Hannemann’s and Bobby’s experiences typical? Is it fair to blame your love handles on a pill or shot that prevents unwanted pregnancy? And if you begin a hormonal method of birth control, such as the Pill, the Shot, the Patch or the Ring, what are the chances that your weight might automatically balloon? The answer, say experts, depends – mostly on the individual woman and her unique biochemistry. After going on hormonal birth control, explains Jerilynn Prior, MD, professor of endocrinology and metabolism at the University of British Columbia in Vancouver, “some women gain weight, some lose, but most stay the same.”

Unfortunately, she adds, there’s no way to predict which you will be: a woman who gains weight, who maintains weight, or even one who loses a few pounds.

Frustrating? You bet. More frustrating still is that no research body is actively investigating this aspect of women’s health. That means the responsibility for monitoring weight-related reactions to hormonal birth control currently falls on each individual woman. And that suggests that all women would be wise to know a thing or two before they pop their first pill, slap on their first patch, or take their first injection.

In this, as in most medical matters, it makes sense to become your own health advocate, to understand how these medicines work and what scientists and doctors know about them – as well as what they’re guessing about.

How Hormonal Methods Work

Hormonal contraceptives contain synthetic forms of the hormones estrogen and progesterone. (The synthetic forms of progesterone are known as progestins.) Most hormonal contraceptives, such as the Pill and the Patch, contain both hormones, but a few, like Depo-Provera and mini-Pills, contain only a progestin.

When you’re not taking a hormonal contraceptive, estrogen dominates the first half of your monthly menstrual cycle (before ovulation) and progesterone dominates the second half. The rise and fall of these hormones turns your uterus into a nurturing place for a fertilized egg.

Hormonal contraceptives smooth out the curves in that pattern. They release their synthetic hormones in constant doses, suppressing ovulation and causing changes in the mucous of your cervix and in the lining of your uterus that make pregnancy highly unlikely.

Estrogen and progesterone are powerful hormones, implicated in all kinds of endocrine functions, so it would be naive to think that adding more of them to your system wouldn’t have some effect on other aspects of your physiology. To wit, check the manufacturer’s label on your birth control and you’ll find a long list of potential side effects, including nausea, headaches, breast tenderness, dizziness, fluid retention, irregular periods and, yes, weight gain.

But just because these side effects appear in print doesn’t mean you’ll experience all (or any) of them. Nor does it mean that each and every physical change you undergo after starting a hormonal contraceptive is necessarily related to it. And that includes weight gain.

“Women seem to learn early to blame a lot of side effects on their birth control,” says Katharine O’Connell, MD, a clinical instructor in obstetrics and gynecology at Columbia University Medical Center in New York. But, says O’Connell, when women were given placebo (fake) birth control pills in recent studies, they reported the same physical complaints – including weight gain – as women who were popping the real hormone-rich Pill.

Back to the Sixties

Thirty years ago, women were well within their rights to blame all sorts of health complaints on the revolutionary new Pill. That’s because when birth control pills first became available in the 1960s, they contained up to five times more estrogen and up to 25 times more progestin than today’s formulations. At those whopping-high doses, side effects were very common – and potentially a lot more dangerous.

Today’s Pill still carries an increased risk of stroke or heart attack, especially for women who smoke or who are over 35 years old, but the risk, according to experts, was much, much greater 30 and 40 years ago.

Piling on the pounds after going on the Pill was also more common back then. Studies using those early high-dose pills tended to show an average weight gain of about 5 pounds. (Studies of today’s lower-dose pills tend to show no weight change – at least for the “average” woman. More about that later.)

Bad reputations, it seems, die hard. “Even though the dose of hormones has come down over the years to very low levels, the fears don’t seem to go away,” says O’Connell. “I think it’s those fears that tend to drive a lot of women’s concerns about weight gain and other side effects.”

Weighing Evidence

If the Pill has a reputation for packing on extra pounds, that notoriety thrives mostly among women, not their doctors. A group of international researchers recently reviewed 39 of the best clinical trials involving this form of birth control and found no statistical evidence that the pills caused an increase in weight. The findings were the same whether the women took combined oral contraceptives (those containing estrogen and progestin) or the progestin-only version known as the mini-Pill.

That doesn’t mean that you, personally, will not gain weight on the Pill, however; it only means that there is no statistical evidence connecting the Pill to increased weight. Anecdotal evidence (which may be all that matters when you happen to be the anecdote in question) is another matter entirely.

“There do seem to be some people who gain weight on the Pill,” acknowledges Robert A. Hatcher, MD, professor of gynecology and obstetrics at Emory University School of Medicine in Atlanta, Ga. “But,” he adds, “there are also people who, primarily because of the nausea sometimes caused by the Pill, actually lose weight.” (About 20 percent of women taking the Pill experience some nausea, at least for a few weeks.)

The same is true for women using either the Ortho Evra patch, a thin, matchbook-size device that is worn on the skin, or the NuvaRing, a flexible 2-inch ring that is inserted into the vagina. Both of these birth-control devices deliver hormones (estrogen and a progestin) for 21 days out of every month. Studies have not shown that wearers of these devices are more likely to gain weight than women using other contraceptives.

The Mirena intrauterine device (IUD), which is inserted into the uterus to prevent pregnancy for up to five years, contains only a progestin. Studies haven’t linked the Mirena to weight gain either, although some women who have used it claim that they found themselves battling the bulge soon after they had the device inserted.

If you should happen to gain weight while on birth control, or if you are already a little heavy, here’s one thing to keep in mind: Recent research suggests that both the Patch and the Pill may offer less-than-optimum pregnancy protection for women weighing more than 155 pounds. (See the sidebar “Pill Alert”)

Shot in the Dark

There is one hormonal birth-control method that does show a clear link to weight problems: Depo-Provera. Also known as the “Shot,” Depo-Provera contains a progestin with the tongue-twisting name of depot-medroxyprogesterone acetate, or DMPA. An injection of the progestin-only Depo-Provera every three months provides protection against pregnancy that is 99.7 percent effective.

But almost from its introduction, Depo-Provera developed a reputation among women for causing weight gain. Doctors, too, noticed problems – but again, only in some of their patients. Katrina Hannemann’s story of her 50-pound blowout on Depo-Provera certainly doesn’t surprise Dr. Hatcher. “I have seen people who have gained 20, 40 and 60 pounds on Depo,” he acknowledges. “However,” he notes, adding his voice to the chorus of maddeningly iffy provisos, “that doesn’t mean that every woman will have that experience.”

Studies of the Shot support Hatcher’s view, or at least they don’t clearly contradict it. While some research has shown a rather troubling gain, other studies have found virtually no weight change among Depo-Provera users. The largest of these studies (3,905 women) was done 30 years ago, when the contraceptive was first coming on the market. That study found that, on average, women gained 5.4 pounds after one year of Depo-Provera injections, 8.1 pounds after two years, 13.8 pounds after four years and – yikes! – 16.5 pounds after six years.

In a recent study from Brazil, women who took Depo-Provera gained an average of 9.5 pounds after five years of injections. But during that same time period, a comparable group of women who didn’t take the contraceptive gained an average of 4 pounds. In other words, all the women (whose average age was 33) gained weight – although the Depo-Provera users did so at more than double the rate.

Several more recent and smaller studies have found, however, that the Shot causes no weight gain. One study even reported that some women on Depo-Provera lost a few pounds. The problem is, there is very little detailed information coming out of these studies that enables a woman to examine her personal risk factors for weight gain, or to know for certain if the weight gain she is experiencing is due to hormonal interference.

“The effects of hormonal birth control are very idiosyncratic,” explains Anthony Scialli, MD, professor of obstetrics and gynecology at Georgetown University in Washington, D.C. “That doesn’t make them not real, however.”

Picking on Progestin

Another once-a-month contraceptive injection, Lunelle, has also been linked to significant weight gain. Like the Patch, the Ring and combination pills, it contains an estrogen-progestin formula. Studies have shown that women taking Lunelle can expect to gain an average of 4 pounds during the first year, although some may gain considerably more – up to 20 or more pounds.

Here’s the kicker: The progestin in Lunelle is DMPA, the same long-acting one that’s used in Depo-Provera. So is weight gain linked to the type of progestin used in a contraceptive? ? Absolutely not, says Scialli. “There has been more baloney written about different progestins than about virtually anything else in medicine,” he says. “There isn’t good evidence that any of them are better than any of the others.”

Drug companies like to claim otherwise, he says, because it helps them carve out a bigger share of the $2-billion-a-year contraceptive market. During the last couple of years, one company, Berlex, has marketed a new birth control pill called Yasmin, which quickly developed a reputation on college campuses and elsewhere as helping women lose – or at least not gain – weight. Berlex claims that Yasmin’s unique (and patented) progestin, called drospirenone, reduces excess sodium and water in the body. The implication is, of course, that it also reduces weight caused by bloating.

But there’s a problem: There’s no solid evidence to support the idea that Yasmin is any different than other oral contraceptives when it comes to weight gain or loss. Even Berlex admits that. “It’s not a weight-loss pill,” states Kim Schillace, manager of product public relations at Berlex. “Women should not expect to lose weight on Yasmin.”

Getting Hip to Hormones

So, are you only imagining that your clothes started fitting more snugly after you began taking a hormonal contraceptive? To sort that out, consider a few possible scenarios …

EXPLANATION 1: Excess estrogen may be causing water-weight gain.
Contraceptives that contain estrogen cause some women to retain more fluid than usual. The results: bloating, breast tenderness and, possibly, weight gain. The more estrogen in the contraceptive, the more likely a woman will experience this “water weight.” Usually the weight gain is no more than 6 pounds, and it tends to go away after a few months. The water-weight explanation may make sense in cases such as that of Kimberly Bobby, who gained only a few pounds, but it doesn’t help decipher what happened to Katrina Hannemann and other women who add fat – lots of it – after going on a hormonal contraceptive.

EXPLANATION 2: The weight gain may be due to a lifestyle change.
Several experts we consulted suggested that Hannemann may simply have experienced an exaggerated version of the “freshman 15” – the significant weight gain that many students encounter during their first year at college.

One recent study, which followed 60 students at Cornell University for their first three months on campus, found that young women gain, on average, a third of a pound per week. The researchers blamed the freshmen’s bulging waistlines on all-you-can-eat dining halls and an unlimited supply of junk food in the dorms.

You don’t have to be a college student to put on weight as you venture into the adult world, either. Almost as soon as your body matures, your percentage of body fat tends to increase, producing an ever-decreasing need for calories.

And then there are hybrid factors. If a woman who is used to eating small meals falls in love with a man who eats more, she may do two things at once: begin using hormonal birth control and start eating more because she’s suddenly spending her days with a bigger eater. Unless she pays close attention to these changes – and makes subsequent adjustments in her eating habits and activity levels – she may very well start putting on significant weight.

EXPLANATION 3: Progesterone may be causing insensitivity to insulin.
Another, albeit unproven, theory for birth-control-related weight gain suggests that when levels of progesterone are high, some women’s sensitivity to insulin (a hormone that converts sugar in the body to energy) plummets.

We already know that insensitivity to insulin can lead to type 2 diabetes, a disease associated with being overweight. But some scientists now think that insulin insensitivity may even cause people without diabetes to fatten up, especially around the abdomen. If that’s true, then taking excess amounts of a progestin might start a chain reaction that eventually leads to excessive weight gain.

“Women feel extremely hungry when there are high levels of insulin in their bodies,” explains Prior, who teaches both metabolism and endocrinology at the University of British Columbia. Hormonal birth control wouldn’t have this effect on all women, she adds, just those who have a genetic tendency toward insulin insensitivity.

What You Can Do

If you’re concerned about gaining weight while on a particular method of birth control – or if you’ve already gained some weight – talk with your healthcare provider. Don’t let him or her brush off your questions or worries.

“In some settings, healthcare providers will play down side effects because they think, ‘Oh, if I tell a woman this, she’s more likely to experience it, or it’s just going to raise her level of anxiety,'” says Amy Allina, program director of the National Women’s Health Network in Washington, D.C.

When you begin using a hormonal birth-control method, pay close attention to how your body is reacting. Don’t anticipate problems, but don’t ignore them, either. Consider keeping a weight, diet and exercise log, and also note any mood, energy or sleep-pattern changes that occur.

“If you find that one method doesn’t suit you, then it’s worth trying another,” advises Prior. Read the labels and evaluate your options: You may want to switch between methods that contain different progestins, for example.

Scialli recommends that women start with generic pills. “There’s no reason, in my opinion, to start on an expensive brand of pills when there are generic birth control pills available at a fraction of the cost,” he says. “The brand ones are not better, they’re just newer.”

If you continue to have weight problems after trying several different formulations of hormones, talk with your doctor about being tested for insulin resistance.

Of course, you don’t have to opt for hormonal contraceptives at all. Most of the experts interviewed for this article recommend barrier methods of birth control: condoms, the cervical cap and the diaphragm (to be used in conjunction with contraceptive jelly or foam). When used properly, such methods offer just as much protection against pregnancy and none of the hormone-related health risks. Condoms also protect against sexually transmitted diseases, including HIV.

The most important thing is to get informed. Do some research online, pepper your doc with questions, read a book on hormonal health, and then do some more asking around. If nothing else, you’ll learn a lot about how your body’s endocrine system works, and that can give you insights into other aspects of your metabolism and general health.

Looking back, Hannemann says she wishes she had done more research and talked to more people before selecting her method of birth control. “I should have gotten a more well-rounded opinion before I made the choice I did,” she asserts.

Remember, though, that just because your friend (or sister or neighbor) had a good or bad experience with a particular type of birth control doesn’t mean you’ll have the same experience. As the research shows, the way a woman’s body reacts to a particular contraceptive – like the choice of the contraceptive itself – is a very personal matter indeed.

Susan Perry writes frequently about women’s health. She has written several books, including Natural Menopause: The Complete Guide (Perseus, 1996) and Nightmare: Women and the Dalkon Shield (Macmillan, 1985).

SIDEBARS:
Pill Alert for Heavier Women

If you weigh 155 pounds or more, you’re 60 percent more likely than your thinner friends to get pregnant while on birth control pills, according to a recent study in the medical journal Obstetrics & Gynecology. The lower the pill dose, the higher the risk, say the University of Washington researchers who conducted the study. They speculate that heavy women who are using other low-dose hormonal methods of birth control, such as the Patch, may have a similar risk.

What does weight have to do with it? Heavy women may need higher levels of hormones to prevent pregnancy because of their faster metabolic rate. Or the hormones may be lodging in the heavy women’s excess fat rather than going into the bloodstream, where they’re needed to get their work done.

Worried? You’re not alone. According to the Centers for Disease Control and Prevention, the average weight of women in the United States is 152 pounds. If you fall into the 155+ weight category, talk to your doctor about using a different contraceptive. In the meantime, you might want to use condoms for backup protection.

Resources
BOOKS

Hormonal Balance: Understanding Hormones, Weight, and Your Metabolism by Scott Isaacs, Todd Leopold and Neil B. Shulman (Bull Publishing, 2002). Learn about all of the hormone systems in your body – from estrogen to insulin.

Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement and Reproductive Health by Toni Weschler (Quill, 2001). Understand and use your body’s hormone cycles for birth control.

WEB
www.womenshealthnetwork.org – National Women’s Health Network

www.fda.gov/fdac/features/1997/babyguide.pdf – Food and Drug Administration’s birth-control guide

www.womenshealthspecialists.org – Women’s Health Specialists (click on health, then birth control)

www.managingcontraception.com/pdffiles.html – Managing Contraception (coauthored by Dr. Hatcher) is available online

www.plannedparenthood.org/bc – Planned Parenthood birth-control information

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