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Depo-Provera was approved for use as a contraceptive by Health Canada in April, 1997 after several previous applications by the manufacturer had been denied. Canada now joins over 90 other countries where Depo-Provera is approved, including the U.S.

A synthetic form of the hormone progesterone, Depo-Provera is a very effective contraceptive when given to a woman by injection every three months. For the past 20 years, it has also been the subject of much debate and controversy in Canada and internationally about its risks and benefits to women's health and about many of the circumstances of how the drug has been tested and used.

Many women's health and community agencies, including Women's Health Clinic, international development organizations and others have monitored this issue for almost two decades and opposed formal approval of Depo-Provera for contraceptive use. As part of the Canadian Coalition on Depo-Provera, WHC took that position largely because of concerns about specific health risks, because of what is still not known about the drug, and to highlight the potential social misuses of Depo-Provera. We urged the federal government to establish a registry of women given the drug.

Prior to April, Canadian doctors could prescribe Depo-Provera as a contraceptive because it was approved in Canada for other uses - endometriosis and the palliative treatment of certain cancers - but the manufacturer could not advertise the drug as a contraceptive. (This is true for other drugs that are known to be effective but do not have formal approval for particular indications.)

With Depo-Provera now marketed as a contraceptive, more doctors may consider prescribing it; more ads are directed to women consumers (many ads already reach Canada through U.S. women's and teen magazines although prescription drugs are only supposed to be advertised to doctors), and the manufacturer, Upjohn-Pharmacia, gains additional credibility in Canada and internationally. Approval is also healthy for sales and profits.

Since many concerns regarding its use were not addressed prior to approval, it is timely to assess what is known about the drug's risks and benefits. Was there any new information upon which Health Canada may have based its approval? What lessons have we learned following this issue over the years? How can we apply this knowledge to improve the delivery of quality reproductive health care for women, especially young women who in Canada are a particular target group for Depo-Provera?

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Bringing Depo-Provera Home: A Partial History

In 1981, a delegation of Canadian women attended the 2nd International Conference on Women's Health in Geneva. We met with health providers and activists from India, Bangladesh, Thailand and Latin America, many of whom were highly critical about the use of Depo-Provera in population control programs and in clinical trials in their countries. Accurate information about the drug was scarce; many women thought it was approved in the U.S. and Canada at that time (it wasn't) and serious questions were raised about its use in settings such as refugee camps, where women had no choice but to receive "the shot," often with no explanation. In this heavy-handed approach, contraceptives were seen as the key to population control.

There is now greater formal recognition by the U.N. and international agencies that birth rates fall when women's education and status are improved and that contraceptives must be available along with a good system of primary health care, social supports and health education. However, governments rarely allocate sufficient resources to make this a reality.

Third world delegates at the conference asked us to send them hard-to-find research data on Depo-Provera, and to ensure that the drug was carefully reviewed by our regulatory bodies if it was approved. Many of us gathered extensive files over the next five years which we shared.

In November 1985, after a Food and Drug Administration public inquiry panel denied approval of Depo-Provera for contraceptive use in the U.S., citing concerns about long-term safety, the Globe and Mail reported that the drug was about to be approved in Canada. An Upjohn spokesperson was quoted saying that Depo-Provera won't be opposed here like in the U.S. "We do things in a more private way in Canada... Here it is a matter between us and Health and Welfare." Approval in Canada would have been strategic for the company at a time of U.S. refusal and as a possible site of export.

The issue had come home. Concerned health providers, consumers, women's health, disability and international development NGOs formed the Canadian Coalition on Depo-Provera to demand: public hearings into long term safety issues; more research in Canada and internationally on women's experiences with Depo-Provera; and that submissions by marketing companies be made public and marketing practices reviewed.

The federal government eventually agreed to closed hearings in 5 cities across Canada in 1986. Scores of groups and individuals presented briefs. Some supported approval, but many addressed concerns about the range of the drug's side effects, possible long-term risks to women's health, and documented cases of use of the drug in Canada without adequate informed consent, particularly by women with disabilities in Ontario institutions, immigrant and refugee women, and Aboriginal women, including many teens. Health Canada did not approve Depo-Provera for contraceptive use then nor in a subsequent appeal in 1992 (after the U.S. finally approved it), noting there were unresolved long term health risks for Canadian women.

The most prominent research studies have focused on Depo-Provera and breast cancer, based on women from 5 sites in Kenya, Thailand and Mexico (WHO, 1991) and from New Zealand (Paul et al, 1989), with a recent analysis pooling the data from these (Skegg et al, 1995). A small study in New Zealand also looked at the effects of Depo-Provera on bone density (Cundy et al, 1991; 1993). While some of the data appear reassuring, other findings remain unclear or inadequately researched. Many concerns remain. We do not know the specific reasons for Health Canada's decision to approve the drug.

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Lessons Learned

From these experiences, we have learned a good deal about what is known and not known about Depo-Provera, about how scientific research may fail to ask relevant questions, how the global pharmaceutical industry works, the politics of drug approval in Canada and internationally, and about the hard decisions health care providers and clients must make when confronted with complex life situations. For example, we've learned that:

• Critiques of research must be scientifically accurate and credible, based on a sound understanding of methods appropriate to the problem. If your facts are wrong, you lose credibility with health professionals, researchers and government. If you have been scrupulous in your work, you can often identify critiques others have missed. The Coalition uses independent epidemiologists to help interpret research findings.
  
  
• It is frustrating, but essential, to try to understand how the Canadian drug approval process works. Closed to public accountability, consumers have no way of finding out the basis on which drugs are considered or approved, except by the lengthy process of applying for documents through the Access to Information Act (The Coalition did this in 1986; another group is seeking information on the current approval). A powerful lobby by the Pharmaceutical Manufacturers' Association of Canada helps ensure close collaboration between industry and government.
  
  
• Recently, the federal government closed the Drug Review Bureau, virtually eliminating scientific drug review within the government. Many scientists, health professionals and consumers are protesting these developments and a new coalition has formed. Where does the approval of Depo-Provera fit in this dismantling of the review process and deregulation of the drug industry?
  
  
• As a new reproductive technology administered by a health care provider, Depo-Provera highlights complex social issues in clinical practice. Because Depo doesn't require daily client action, it is often considered convenient for women who do not/cannot remember to take pills or other client-controlled methods; for women who have had unplanned pregnancies and/or abortions, sometimes as a result of contraceptive failures and who want a highly effective method; for women who don't want their partner to know they are on birth control, for example, women in abusive relationships, subject to coercive sex; women for whom pregnancy presents high risks, such as those struggling with alcohol or solvent abuse. These are complex life situations, in which health providers must help women weigh the risks and difficulties of pregnancy to those of using Depo.

Depo-Provera may help "buy time" for women in difficult situations, but it is not the quick fix solution. Social and other supports are needed to address the often underlying issues of poverty, abuse, and low self-esteem. As well, some providers too readily assume a woman will be "non-compliant" in taking other forms of birth control. Immigrant, refugee and Aboriginal women have complained about providers offering them Depo-Provera as a first choice contraceptive, not taking time to discuss other alternatives and discouraging them from having more children. All clients, but particularly women marginalized in the health care system, need time and sensitive counseling to ensure informed choice. Since Depo has the potential to be misused and its effects remain in the body beyond three months, it should not be a first-choice contraceptive, but considered only after all other alternatives are explored.

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The Next Steps:

Guidelines and Protocols

Given these social concerns and the limitations of the research on Depo-Provera (See Box 2), many health providers and consumers would like to see clearer guidelines and protocols for contraceptive counseling and use that are specific to the situations and health status of Canadian women. For example:

• Since Depo-Provera reduces estrogen needed to build healthy bone mass in young women, particular care should be taken prescribing Depo-Provera to young women. Women preoccupied with weight and dieting or who have eating disorders already tend to have lower levels of estrogen. Canadian women have high rates of osteoporosis; the risk of contributing to such a trend should be an issue of concern.
  
  
• Depo-Provera has a mild, but definite effect on insulin levels. It is suggested that women with diabetes, or a tendency to diabetes, should be closely followed if taking Depo. This is a significant issue for Aboriginal women in Canada who have high rates of diabetes, who as a population do not generally have good access to health care services, and to whom Depo-Provera is often given.
  
  
• While the data on Depo and breast cancer is more reassuring for longer term users, there is a significant, unexplained risk for younger women who were recent users of Depo and took it for a short period of time. In particular, young women considering Depo should be asked about risk factors for breast cancer, but health care providers and clients must recognize that young women cannot easily be screened or monitored for breast cancer through mammography or breast self exam.
  
  
• Depo-Provera, like the pill and other hormonal contraceptives, doesn't protect against sexually transmitted diseases or HIV, and may even facilitate HIV transmission. For increasing numbers of young women, STDs will cause infertility and other problems in later years.

Because of its ease of use, Depo-Provera doesn't require a couple to think about contraception in relation to sex, in contrast, say to barrier methods, or the pill which encourages more self-awareness, responsibility and forethought for women. It may be difficult to encourage safer sex practices and use of condoms with Depo-Provera or other methods that are controlled by providers, especially for very young women, and others who find it hard to negotiate with male partners. This is not unique to Depo-Provera, but is an issue that health care providers must address, given increasing rates of STDs and HIV.

Registry and Research

We renew our call for establishing a registry for Depo-Provera users for research and so women could be notified if future concerns arise. Population health studies are also needed on the use of Depo-Provera in relation to conditions such as diabetes, heart disease, its effects post abortion, and post partum, about which little is known; and for qualitative research on the social issues and contexts of Depo's use as a contraceptive. Knowing to whom it is given, under what circumstances and with what outcomes may lead to a deeper understanding of how to assess social risks, and identify ways clients in difficult situations can be helped to address the roots of the problems they are facing.

There must be new opportunities for health care providers and consumers to work together to develop models of care that empower women /couples to make appropriate, safer contraceptive choices, and achieve healthy, satisfying relationships, free of coercion of any kind.

With Depo-Provera approved, the hard work lies ahead.

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Some Facts About Depo-Provera

• Depo-Provera is an injectable contraceptive, effective when administered every 3 months in doses of 150 mg. It blocks hormonal signals from the hypothalamus and pituitary gland near the brain necessary for ovulation; thickens cervical mucus, making it difficult for sperm to pass through and fertilize an egg; and thins the lining of the uterus, reducing chances for conception and implantation. For every 100 women taking Depo-Provera at correct intervals for one year, less than one will become pregnant.
  
  
• Synthetic progesterone-only contraceptives (progestins) like Depo-Provera may be an appropriate option for women who cannot take estrogen-based contraceptives; who take anti-seizure medication; or who have sickle cell disease.
  
  
• Studies suggest Depo-Provera is protective against endometrial cancer and may protect against ovarian and cervical cancer and pelvic inflammatory disease. More research is needed.
  
  

Side Effects

• Most women using Depo-Provera experience menstrual irregularities such as irregular bleeding or spotting, and for some, heavy bleeding. Amenorrhea (an absence of periods) commonly develops any time during the first year. This may make early detection of pregnancy difficult, while other women may worry unnecessarily that they might be pregnant. Fetal development may be affected by exposure to Depo-Provera. Menstrual irregularities may also mask the onset of menopause.
  
  
• Weight gain affects most women, averaging about 2.3 kg (5 lbs) in the first year and varying after that; some women gain significantly more. The reasons are unclear, but it may be that by suppressing estrogen, there is a higher ratio of androgenic (male) hormones, muscle growth and increased appetite.
  
  
• Other side effects may include: acne, breast tenderness, headaches, nervousness, depression and loss of libido. The delay in return to fertility averages 3-6 months, but may be up to 18 months or more for a small number of women. Symptoms may persist 6-8 months or longer after the drug is discontinued.
  
  
• Anyone with blood-clotting problems, unexplained vaginal bleeding or other conditions should discuss these with their health care provider before considering Depo-Provera or other methods.
  
  
• Depo-Provera does not protect against STDs or HIV. Condom use is recommended.

Sources: CPS, 1997; R. Hatcher et al., Contraceptive Technology, 1994.

Research on Depo-Provera: A few concerns...

• Much of the research is based on studies of women with very different health and disease profiles (e.g. rates of breast cancer, osteoporosis, diabetes, heart disease, etc) and lifestyles, diets, other environmental factors and genetics, from Canadian women.
  
  
• Two studies, one by the World Health Organization (WHO, 1991) and one in New Zealand (Paul et al, 1989) showed increased risk of breast cancer among current and recent users of Depo-Provera, but that risk did not increase with prolonged use. The risk of breast cancer appeared to be increased in women diagnosed at younger than 35, and in women who had used Depo before age 25. Both groups of researchers suggested that Depo-Provera may promote the development of new tumours or accelerate pre-existing ones. Because younger women have dense breast tissue, screening methods like mammography are not effective in monitoring breast changes.
  
  
• A prospective study of sex trade workers in Thailand found higher HIV seroconversion rates among women using Depo-Provera. The researchers speculate whether the thinning of the vaginal epithelium may create small tears and facilitate the transmission of HIV (Ungchusak et al, 1996).
  
  
• Research in New Zealand showed that 30 women on Depo-Provera had lower bone mass than other women of the same age, but that this effect was reversible when Depo-Provera was discontinued. (Cundy, 1991; 1993) A pilot study showed a decrease in bone mass among adolescents on Depo-Provera, while a control group had increasing bone mass (Blair et al, 1995). Two large-scale prospective studies currently underway do not include women under age 18. Upjohn is supposed to have completed a 7 year prospective study on bone density involving 450 women, ages 25-35; as yet there is no report.
  
  
• Depo-Provera affects insulin response, but there is little research on the implications for diabetes, especially in high risk populations.
  
  
• Virtually no research has been done on the impacts of Depo-Provera on the risk factors for heart disease and stroke.
  
  
• We don't know much about the impacts of Depo-Provera on a woman's post partum or post abortion hormonal state. The drug is often administered at these times.