SAN DIEGO — If you’re a woman aged 18 to 34, you may have seen a Phexxi ad during a commercial break on Hulu. Or you could have come across the product — a non-hormonal contraceptive gel that women can use within an hour before having sex — while scrolling through Instagram, somewhere between a recipe for Paleo bagels and an ode to body positivity.

Phexxi went on sale in September in the United States, after receiving approval from the Food and Drug Administration. Prescriptions for Phexxi are in the low thousands, according to its publicly traded parent company, Evofem — about 17,280. This is puny compared to the estimated 8.6 million women who have undergone female sterilization or the 6.6 million women on the Pill.

But Saundra Pelletier, the chief executive officer of Evofem, is hoping to reach a generation that, unlike their foremothers, who were “liberated” by the Pill, then schooled to insist on condoms, have grown up with hormones as the default birth control option.

“I think it’s insane that women have not had an option like this before now,” she said in May.

The conference rooms in Evofem’s offices are all named after women who left a mark on the world: Ruth Bader Ginsburg, Rosa Parks, Marie Curie. A stylized Joan of Arc, in hot pink, looms on a screen in the “war room.” In the cafeteria, “feminism” is written on a plaque, along with a definition of the word.

The messaging in Ms. Pelletier’s personal office is even fiercer. In the bathroom, a cup holding a toothbrush and toothpaste on the sink reads: “Tears of My Enemies.” A shower curtain (yes, there’s a shower in her office) proclaims in bold, uppercase letters, “Here’s to strong women/May we know them/May we be them/May we raise them.”

The shower is there because Ms. Pelletier, 51, works a lot. When she was diagnosed with cancer in 2018, she sought doctors who would accept that she had no intention of taking a break while undergoing treatment.

“If I stop working, I’m going to take pain meds all day, watch ‘The Price Is Right’ and end up in the fetal position in the corner,” she said. So through six months of chemotherapy and through a double mastectomy, a hysterectomy and an oophorectomy, she continued working, even appearing at conferences around the country.

Phexxi is intended not only for women questioning whether they want to take hormones, an increasingly vocal contingent during a boom of wellness culture; it is also for women who are told not to take them. Women with breast cancer, for example.

Phexxi’s mechanism is simple: the gel alters the pH of the vagina to make it more acidic and inhospitable to sperm. The product is about 93 percent effective with perfect use in clinical trials reviewed by the F.D.A., and 86 percent effective with typical use.

That rate falls somewhere between the rates for condoms and diaphragms. (Condoms prevent pregnancy 87 percent of the time with typical use and diaphragms do so 83 percent of the time with typical use, according to the Centers for Disease Control and Prevention. The Pill has a 93 percent typical-use effectiveness rate.)

Repackaged spermicide? Absolutely not, said Dr. Kelly Culwell, the chief medical officer of Evofem’. “Spermicide is essentially a detergent,” Dr. Culwell said. “It destroys cell membranes. It basically busts sperm open.” Furthermore, spermicide can erode the cell membranes of the vaginal wall, according to the World Health Organization, which could make frequent users more prone to contracting a sexually transmitted disease or infection.

Evofem’s investor materials suggest that there are millions of women in the market for a simple, use-only-when-you-need-it, non-hormonal option like Phexxi. They are “the women who are using condoms, relying on the pullout method and hoping for the best, or the women using a natural family-planning method,” said Erin Turner, a brand manager at Evofem.

Dr. Meera Shah, the author of a book about abortion and the chief medical officer for Planned Parenthood in the Hudson Peconic region, is one of about 5,400 American health providers who have prescribed Phexxi, according to Evofem. She oversees 10 clinics. “Clinicians have been reaching out to me saying everyone’s asking for Phexxi,” Dr. Shah said. “The demand is there.”

Comparing Side Effects

History is littered with the plastic cases of rejected birth-control methods (anyone remember the briefly voguish Lady Comp? Or the sponge?).

Still, many women are dissatisfied with the options on offer — and there is a growing willingness to voice that discontent. On average, women try three to four different birth control methods throughout their lives, according to a recent survey by the Kaiser Family Foundation. In one study, 91 percent of women said that no birth control method had all of the features that they consider “extremely important.”

And in recent years more people are asking questions about what they put into their bodies, embracing routines and products that feel more “natural” to them and rejecting things they perceive as toxic.

“We need more innovation and more options,” said Erica Chidu, a founder and the chief executive of LOOM, a sexual health education platform. “For people who hate taking the Pill, who hate condoms and the sensation of them,” she said of Phexxi, “this seems like a cool, revelatory thing.”

Complaints about available birth control methods vary. Some people are scared off by accounts of the pain involved with the insertion of an intrauterine device. “Some people don’t want to have an IUD in their body,” Ms. Chidu said. Some do not like the side effects of birth control pills, which can include headaches, a decreased libido and emotional roller coasters.

Others are concerned about serious health risks, like blood clotting. Recently, after the F.D.A. paused use of a coronavirus vaccine because of its associated risk of blood clots, some women wondered why medical professionals are not more worried around the blood-clotting risks of birth control pills (Blood clots associated with the Pill can occur in the leg or the lungs, but the risk is very low.)

“Women have suffered far too long with serious side effects that nobody talks about,” Ms. Pelletier said. The most common side effects associated with Phexxi are vaginal burning and itching.

For some, taking synthetic hormones out of their routine is an opportunity to become more in sync with their body’s unaltered cycle (hormonal birth control prevents ovulation). “When you’re able to move through the four phases of a menstrual cycle from a place of autonomy, it allows you to have more control over your life and your moods and what’s going on with you,” Ms. Chidu said.

Ms. Pelletier has five tattoos running down her back that include depictions of the goddesses Artemis and Aphrodite; a symbol for the goddess of the sea; and a Sanskrit mantra for compassion. She insisted that all of them be completed in one session, and the process took about four hours.

When she underwent chemotherapy, Ms. Pelletier asked for “the harshest, most severe treatment,” so she could be done with it as quickly as possible. “I wanted chemo hard-core,” she said. The treatment was incredibly draining, and while she decided to stick it out, she realized quickly that she did not want her son, now 14, to see the toll it took on her.

“He would run home from school and he would literally sprint all the way up the stairs to see if I was there and alive,” she said. Then he would lie in bed and “pat me for, like, half an hour,” she said. “Finally I was like, OK, I’ve got to stop this. I can’t be in bed when he’s here. I thought it was damaging him psychologically.” To shield her son from her pain and exhaustion, Ms. Pelletier, now no longer in active treatment, shifted her chemotherapy schedule so she would be up and about when he came home.

She learned to be a fighter as a child growing up in Caribou, a small town in northern Maine, raging that girls had to take sewing and home economics classes. For one class project, she performed a section from “The Children’s Hour,” a play written in the 1930s about two women shunned for being perceived as lesbians. Her parents were dismayed. “My poor father would say, ‘We can’t go to church now,’” Ms. Pelletier said.

She spent afternoons playing Skat, a card game, with her mother and her mother’s friends, who taught her aphorisms such as “if someone shows you who they are, you should believe them” or “there’s nothing a hard drink can’t fix.”

“I was 12,” Ms. Pelletier said. “They were seasoned and wise and had been through hell. What they hoped for me was that I would get out and never come back.” Which she did. (Though “on really bad days, I get in my infrared sleeping bag and I drink a martini,” she said. “Grey Goose, very dry with a lemon twist”).

‘Reality Checks’

After attending Husson University in Bangor, Maine, Ms. Pelletier worked as a sales representative at G.D. Searle, the pharmaceutical company that first developed the birth control pill, now owned by Pfizer. She rose to become a head of global new business in the women’s health division. “Working in pharma taught me how to talk with influence, how to behave, how to present, how to use certain levers, how to read a room,” she said.

In 2009, she founded a nonprofit called Woman Care Global, which focused on reproductive health around the world. During her time there, in 2013, Ms. Pelletier came across a product called Amphora, developed by a team of scientists at Rush University in Chicago, and owned by a company called EvoMed that was in trouble. “They didn’t have the right strategy, they didn’t have the financing, the leadership,” she said.

Eventually, the investors in EvoMed separated the women’s health division, created a new company called Evofem and put Ms. Pelletier in charge. Amphora was later renamed Phexxi (the first two letters represent pH and the double X is for the sex chromosome.) In 2015, she became the company’s C.E.O. Since then, she has led Evofem in raising $491 million from investors and hired 128 employees.

When interviewing job candidates, Ms. Pelletier asks applicants to explain their views on feminism, to name a few prominent feminists and to talk about whether they think men and women are treated equally. “Sometimes they get nervous and squeamish,” she said. “You can tell they look at the door like, ‘Am I going to have to run out of here?’”

Besides expecting her employees to be feminists, Ms. Pelletier also asks them to leave their egos “in the parking lot” and to be honest. “You don’t have to say you have a medical appointment or use your vacation time,” she said. “Just say I’m going to work half a day because I want to go to my kid’s play.”

Ms. Turner, the brand manager, who has worked with Ms. Pelletier for six years, praised the office environment. “My sister works in finance and she was sent home for not wearing the right shoes,” she said. “I’m like, ‘Are you kidding me? My C.E.O. is running around in this crazy ‘My Favorite F-word Is Feminism’ shirt. This is an amazing culture to work in.”

Though she has always been forthright, Ms. Pelletier said that after battling cancer, she decided she was done with “superficial nicety.”

She started implementing 15-minute “reality checks” every other week with her executive team. “I say, ‘This is not going well, here’s why, and here’s what I suggest you do to correct it. Either you take my idea or you come up with a better one,’” she said. “People are shocked. I believe very few people have been given honest, transparent feedback from their leadership.”

Ms. Pelletier is not afraid to tell investors when they cross a line. One investor called her delusional for thinking that she is “some crusader who can change the history of hormones” and suggested that she quit her job. She decided to respond. “‘What you said really hurt my feelings and I think you should take it back because it wasn’t true,’” she quoted from one email.

There could be a lot more of those emails in the future. Retail investors direct their frustration with Evofem’s low stock price at Ms. Pelletier on social media — sometimes viciously. (Evofem’s stock is trading for about $1 now; its high in the last year was $4.88.) Phexxi has a long way to go before profitability, and Evofem is testing a major second use for it, with high stakes.

If the testing goes well and the F.D.A. approves it, the Phexxi formulation could be used as a prevention method for the sexually transmitted infections chlamydia and gonorrhea. They are a growing problem in the United States, with cases having increased every year for more than half a decade.

Public health officials have expressed widespread concern over gonorrhea’s growing resistance to antibiotics. Currently, Evofem is recruiting women for a Phase 3 trial.

“The hardest days are now,” Ms. Pelletier said. “It’s like being completely naked and walking down the street. Everybody sees what you do and everybody is an armchair quarterback.”

But if her directness about sexism and misogyny bothers people, Ms. Pelletier does not care. “I am not going to be a C.E.O. of this company and pretend that I think equality exists,” she said. “Because it doesn’t.”