When the Food and Drug Administration stopped using Johnson & Johnson’s Covid-19 vaccine to assess the risk of blood clots in women under the age of 50 last month, many scientists found that birth control pills-related clots were far more common.

The comparison should convince women of the safety of the vaccine. Instead, it has caused anger in some areas – not about the break, but about the fact that most contraceptives available to women are hundreds of times riskier and yet safer alternatives are not in sight.

The blood clots associated with the vaccine were a dangerous type in the brain, while birth control pills increase the chances of a blood clot in the leg or lungs – a point that was quickly established by many experts. But the distinction made little difference to some women.

“Where was everyone’s concern about blood clots when we started putting 14-year-old girls on the pill,” one woman wrote on Twitter.

Another said, “If birth control were made for men, it would taste like bacon and be free.”

Some women heard on social media and elsewhere that they shouldn’t complain because they chose to take birth control in order to understand the risks involved. “That only doubled me,” said Mia Brett, a legal history expert who focuses on race and sexuality. “This is such a common response to women’s health care – that we point it out and it gets rejected.”

The tide of anger on the internet was familiar to women health experts. “You should be angry – women’s health just isn’t given equal consideration,” said Dr. Eve Feinberg, a reproductive endocrinologist and infertility specialist at Northwestern University. “There is a great deal of sexual bias in all of medicine.”

Dr. Feinberg and many of the women on the internet recognize that contraceptives have put women in control of their fertility, and the benefits far outweigh the harms. Rebecca Fishbein, a 31-year-old cultural writer, began tweeting about the inadequacy of birth control pills almost immediately after the break was announced.

“Birth control is an incredible invention, thank god we have it,” she said in an interview last month. “I will fight anyone who tried to take it away.”

Contraceptives have also improved over the years, with intrauterine devices and oral options that offer ultra-low estrogen doses. “Overall, it’s incredibly safe,” said Dr. Feinberg. “Everything we do involves risks.”

Dr. However, Feinberg said it was crucial for health care providers to discuss the risks with their patients and coach them on worrying symptoms – a conversation many women said they never had.

Kelly Tyrrell, a communications professional in Madison, Wisconsin, was 37 years old when doctors discovered potentially fatal blood clots in her lungs.

Ms. Tyrrell is an endurance athlete – wiry, strong, and not prone to anxiety. In early 2019, she began to wake up with pain in her left calf. After a particularly bad morning, an urgent care visit revealed that she had high blood levels of “D-dimer,” a fragment of protein that indicates the presence of clots.

She had been on birth control pills for 25 years, but none of the doctors made a connection. Instead, they said that given their age, fitness, and the lack of other risk factors, it was unlikely that their symptoms would stem from a blood clot. They sent her home with instructions to stretch her calf muscle.

When she experienced chest tightness while running in Hawaii after her grandmother’s funeral, doctors said the cause was likely stress and anxiety. In July 2019, she finished a 100 km race in Colorado, assuming that her sore lungs and purple lips were the result of 19 hours of running at high altitude.

But she knew something was seriously wrong on the morning of October 24, 2019 when she became short of breath after walking up a short flight of stairs.

This time, after ruling out heart problems, the doctors scanned her lungs and found multiple blood clots. One had cut off blood flow to part of her right lung.

“I burst into tears immediately,” recalled Ms. Tyrrell. Doctors put her on a blood thinning regimen – and told her never to touch estrogen again. Ms. Tyrrell switched to a copper IUD. Over time, she added, the incident had escalated into sharp anger, which was renewed by the news from Johnson & Johnson.

“Part of my anger was that a drug I was taking to control my fertility was threatening my mortality,” she said. “I’m angry that I wasn’t given better advice about this risk or what to look for.”

Emily Farris, 36, was prescribed oral contraceptives at the age of 18 to help with migraines. In all of the conversations she has had with her many doctors over the years, “blood clots have never been formed,” she said in an interview.

On Twitter, some critics pointed out that the birth control pack inserts clearly describe the risk of blood clots. “My answer to that is a little incredulous,” said Dr. Farris, a political scientist at Texas Christian University in Fort Worth.

The supplements for most drugs have a long list of possible side effects, which “puts a heavy burden on people trying to sort the medical research to sort out what probability and statistics mean,” she said.

Even with a doctoral degree, “I cannot assess these risks,” added Dr. Farris added. “I think most Americans need someone to translate the legal kind of brochure into real terms.”

This explanation came far too late for Mrs. Tyrrell. Her lungs haven’t felt this way since she was diagnosed, but she’s not sure if it was due to persistent damage from a previous blood clot, new blood clots to worry about, or simply because of her age don’t think about it anymore. “