On a busy day at the Kwapong Health Centre in rural Ghana, Beatrice Nyamekye put contraceptive implants into the arms of a half-dozen women, and gave eight or nine more a three-month hormonal injection to prevent pregnancy. A few sought condoms or birth control pills, but most wanted something longer lasting.

“They like the implants and injections best of all,” said Ms. Nyamekye, a community health nurse. “It frees them from worry, and it is private. They don’t have to even discuss it with a husband or a partner.”

The bustle at the Kwapong clinic is echoed all over Ghana, and across much of sub-Saharan Africa, where women have the world’s lowest rate of access to contraception: Just 26 percent of women of reproductive age in the region are using a modern contraceptive method — something other than the rhythm or withdrawal methods — according to the United Nations Population Fund, known as UNFPA, which works on reproductive and maternal health.

But that is changing as more women have been able to get methods that give them a fast, affordable and discreet boost of reproductive autonomy. Over the past decade, the number of women in the region using modern contraception has nearly doubled to 66 million.

“We’ve made progress, and it’s growing: You’re going to see huge numbers of women gaining access in the near future,” said Esi Asare Prah, who manages advocacy for the Ghana office of MSI, a reproductive health nonprofit.

Three factors are driving the change. First, more girls and women are becoming educated: they have more knowledge about contraceptives, often through social media that reaches even into the farthest corners of the region. And they have bigger ambitions, for careers and experiences, that will be easier to fulfill if they delay having children.

Second, the range of contraceptive options available has improved, as generic drug makers have brought more affordable hormonal injections and implants to market.

And third, better roads and planning have made it possible to get contraception to rural areas, like this one, a nine-hour drive from the port in the capital, Accra, where the commodities were shipped from manufacturers in China and Brazil.

The improved access results in tangible gains for women. At a bustling MSI clinic in the town of Kumasi, Faustina Saahene, who runs the operation, said women from the country’s large Muslim minority appreciate implants and IUDs for their discretion, which allows them to space their pregnancies without openly challenging husbands who want them to have a lot of children.

She also encourages them for younger, unmarried women, who may be overly optimistic about the commitment of their current partner to support a child — and may not realize how much a pregnancy could limit their options.

“Your education, your career, even sexual pleasure: having children disrupts,” Ms. Saahene said before ushering another client in the exam room doors.

Across the region, control over access to contraception has largely been taken out of the hands of doctors, despite resistance from physicians’ associations, which are concerned about the loss of a reliable revenue stream. In many countries, community health workers go door-to-door with birth control pills and give Depo-Provera shots on the spot. A self-administered injection is increasingly available in corner stores, where young women can buy one without the risk of judgmental questions from a nurse or doctor.

In Ghana, nurses like Ms. Nyamekye inform women that they have cheap, discreet options. When she dropped by a roadside beauty salon not long ago, she chatted with women waiting on a wooden bench to have their hair braided. With just a few questions, she sparked a boisterous conversation: One woman said she thought an implant might make her gain weight (possible, Ms. Nyamekye agreed), and another said she might drop into the clinic for an injection, prompting her braider to tease her about fast-moving developments with a new boyfriend.

Sub-Saharan Africa has the world’s youngest and fastest growing population; it is projected to nearly double, to 2.5 billion people, by 2050.

At the Kwapong clinic, there’s a room set aside for adolescent girls, where movies play on a big TV and a specially trained nurse is on hand to answer questions from shy teenagers who slip in wearing pleated school uniforms. Emanuelle, 15, who said she was newly sexually active with her first boyfriend, opted for an injection after chatting with the nurse. She planned to tell only her best friend about it. It was a better choice than the pill — the only method she knew about before her clinic visit — because the uncle she lives with might find those and know what they’re for, she said.

A decade ago in Kwapong, the only options Ms. Nyamekye had for women were condoms or pills, she said. Or, once a year, MSI would come to town with a clinic built into a bus, staffed by midwives, who inserted IUDs into lines of waiting women.

For all the current progress, the U.N. reports that 19 percent of reproductive-age women in sub-Saharan Africa had unmet contraceptive need in 2022, the last year for which there is data, meaning that they wanted to delay or limit childbearing but were not using any modern method.

Supply issues persist as well. In a recent three-month spell, the Kwapong clinic ran short of everything except pills and condoms when supplies did not arrive from Accra.

That’s a symptom of how hard it is to get contraception to places like this, in a system in which global health agencies, governments, drug companies and shipping firms often have more say about what contraceptives women can choose than the women themselves.

The bulk of family planning products in Africa are procured by the United States Agency for International Development or by UNFPA, with support from the Bill & Melinda Gates Foundation. This model dates back more than half a century, to an era when wealthy nations sought to control the fast growing populations in poor countries.

The big global health agencies invested in expanding access to family planning as a logical complement to reducing child mortality and improving girls’ education. But most governments in Africa left it out of their own budgets even though it delivered enormous gains for women’s health, educational levels, economic participation and well-being.

Countries with limited budgets usually opted to pay for health services seen as more essential, such as vaccines, instead of for reproductive health, said Dr. Ayman Abdelmohsen, chief of the family planning branch of the technical division of UNFPA, because they produce more immediate returns.

But a recent push by UNFPA to have low-income countries assume more of the cost has led 44 governments to sign on to a new funding model that commits them to annually increase their contributions to reproductive health.

Even so, there was a significant global shortfall of about $95 million last year for the purchase of products. Donors currently pay for a large share of the products, but their funding for 2022 was nearly 15 percent less than it was in 2019, as the climate crisis, the war in Ukraine and other new priorities shrunk global health budgets. Support for the programs by governments in Africa has also stagnated as countries have struggled with soaring food and energy prices.

The good news is that prices for the newer contraceptives have fallen dramatically over the last 15 years, thanks in part to promises of huge bulk orders brokered by the Gates Foundation, which bet big on the idea that the long-acting methods would appeal to many women in sub-Saharan Africa. Hormonal implants made by Bayer and Merck, for example, fell to $8.62 in 2022, from $18 each in 2010, and sales went up to 10.8 million units from 1.7 million in the same period.

But that price is still a challenge for low-income countries, where total government health spending each year averages $10 per person. Pills and condoms are more expensive in the longer term, but the upfront cost of long-acting products is a barrier.

It’s not enough to get the contraceptives to a clinic: Health workers have to be trained to insert IUDs or implants, and someone has to pay for that, Dr. Abdelmohsen said.

Hormonal IUDs are still scarce in Africa, and cost more than $10 each; Dr. Anita Zaidi, who leads gender equality work for the Gates Foundation, said the nonprofit is investing in research and development for new long-acting products, and also seeking out manufacturers in developing countries who can make existing ones even more cheaply.

The foundation and others are also investing in new efforts to track data — on what companies are making which products, which countries are ordering them and when they will be delivered — to try to ensure that clinics don’t run short. They also want to better track which methods African women want, and why women who say they want to use contraception aren’t. Is it cost? Access? Cultural norms, such as providers’ unwillingness to deliver to unmarried women?

Gifty Awauah, 33, who works in a small roadside hair salon in Kwapong, gets a regular three-month injection. She had her first child while she was still in school. “When I got pregnant at 17, it was not planned — family planning was not accessible like it is now,” she said. “You had to travel to the city and pay: So much money was involved.”

She had to quit school when she got pregnant; if she’d had the options she has now, her life might have looked different. “Had it been like now I wouldn’t have been pregnant,” she said. “I’d have moved ahead in life, I’d have studied, I’d be a judge now, or a nurse.”