As states ban abortion, demand for birth control and abortion pills is rising.

Less than 48 hours after the Supreme Court said states could ban abortion, health care providers have noticed an increase in interest in birth control, emergency contraception and abortion pills.

Especially in the nine states that had banned the procedure by Sunday, women appeared to fear a tightening of access to family planning resources and some were stockpiling options. The increased demand reflected a growing concern that the court’s ruling was part of a broader effort to prevent Americans from determining for themselves when and whether to become pregnant.

After Katie Thomas, 42, learned that abortion would soon become illegal in Arkansas, she purchased abortion pills for her 16-year-old daughter.

“Just the thought of something happening to my daughter, whether by force or by her choice, and there’s an unwanted pregnancy, I want to be able to handle that,” Ms. Thomas said. “If I need to handle that on my own, then I will.”

Ms. Thomas, of Little Rock, said she had already been stocking up on Plan B, the emergency contraceptive, in case her 21-year-old son and his girlfriend ever needed it. She bought even more on Friday.

Abigail Carroll, the 22-year-old founder of Abortion Access Nashville, said that some young women were stockpiling Plan B, but she cautioned people not to clear the pharmacy shelves so those who need the pills now can obtain them.

Planned Parenthood Southeast in Atlanta was getting more calls than usual from people concerned that their options surrounding pregnancy were diminishing, said Lauren Frazier, a spokeswoman. “They want to know how many birth control pills they can stockpile,” said Ms. Frazier, who said there also were questions about emergency contraception, vasectomies and tubal ligations.

Even before the Supreme Court ruling, abortion pills were becoming more popular. In 2020, more than half of the abortions in the United States were medication abortions, according to a report by the Guttmacher Institute, which supports access to abortion. And that number is expected to rise.

Conservative states that have banned medication abortion will probably find it difficult to enforce: Many patients choose the procedure because it is less expensive, less invasive and affords more privacy than surgical abortions.

Kiki Freedman, the chief executive of Hey Jane, a start-up that provides telemedicine abortions to women in six states, said patient demand doubled after the court’s decision to overturn Roe v. Wade. Traffic to its website on Friday was 10 times larger than usual.

The court decision also appeared to drive interest in long-acting reversible birth control methods, such as intrauterine devices.

A similar phenomenon occurred after Donald J. Trump was elected president in 2016, according to a 2019 study published in JAMA Internal Medicine. The study did not assess the motivation of people who received IUDs then, but there were concerns women could lose access to birth control after Mr. Trump promised to repeal the Affordable Care Act on the campaign trail.

On Friday, one protester in Nashville, Maria French, said she had recently replaced an IUD out of concern that she could lose access to contraception. Abortions are still legal in Tennessee, but the ruling allows the state to effectively ban abortion in the next 30 days.

“I went and got a new one because I saw this come out in the news and I decided that was too scary for my liking,” said Ms. French, 24. She added, “I didn’t want to let mine expire and then need an abortion.”

Reporting was contributed by Pam Belluck, Sydney Cromwell, Jamie McGee and Erica Sweeney.