In June, Taya Vietro walked into her pharmacy to pick up her supply of injectable estrogen, the hormone that’s been sustaining her transition from male to female since 2012.  But the drug was on back order, and the pharmacist said it wouldn’t be available for months. Vietro, a svelte, shy 27-year-old, recalls the staff trying to soothe her.

"They could see it on my face," she said. "My whole world just dropped out from under me."

Concentrated estrogen, paired with a testosterone blocker, is central to what's now known as the "gender-affirmation" process.

In mid-2015, Par Pharmaceuticals and Perrigo Co., which make Delestrogen and generic estradiol valerate, respectively, stopped shipments of the 10-ml, 20-ml, and 40-ml injectable dosages of the hormones, waiting for FDA clearance for their new active-ingredient supplier. That approval is still pending, and existing stock in Philadelphia, a hub for the trans community, seems to have eclipsed this summer.

For a variety of reasons, the United States has struggled with drug shortages for years. Some are life-threatening; others, like this one, are potentially life-altering.

"There is panic," said Celena Morrison, community engagement specialist at the Mazzoni Center, a health center for the LGBTQ community located in Center City. Without estrogen, she explained, a transgender woman's body will build more muscle, and facial hair might return. "In the worst-case scenario, you start to detransition," said Morrison.

Estrogen does come in other forms. Trans women can take pills twice daily or wear patches. Dane Menkin, clinical operations manager at Mazzoni, estimates that half his patients affected by the shortage have switched to pills without a problem.

But some women find the pills not only hard to remember but also inadequate. During the first six months of her transition, Vietro tried the oral form. "Pills didn't work for me," she said.

Menkin has made other arrangements for Vietro, as he has for several patients, finding mail-order pharmacies that compound their own injectable hormones. But this has its drawbacks. First, it's hard to get the combination right. Vietro's dosages have been raised and lowered several times since June, causing a hormonal imbalance that's mentally taxing. "I feel a little bit weaker, more anxious," said Vietro. It's also expensive. Delestrogen and estradiol valerate are covered by insurance, but compounding can cost up to $200 per month.

Vietro's family helps her with the costs, and Menkin recently found her a much more affordable option at about $60 per month. But those who can't afford the out-of-pocket cost, or who don't have doctors to find these specialty pharmacies, look to the streets. "People are opting to get them black-market," said Lisa Pozzi, specialty clinic coordinator at the John F. Kennedy Behavioral Health Center.

Heather Zoumas Lubeski, a spokeswoman for Par Pharmaceuticals, said that the company is "working diligently" to get their new supplier approved. Andrea Fisher of the FDA said that the agency "recognizes this is an important drug, and is working with the drug manufacturers so that the drug may return to the market as quickly as possible, while ensuring safety for patients." Delestrogen and its generic counterpart are not only used for transitioning but also, in modest doses, to regulate hormonal imbalance in menopausal women. (Perrigo did not respond to repeated requests for comment.)

In September, hundreds of trans-support clinics and health-care providers across the country signed a letter to Par and Perrigo demanding immediate action.

"The shortage is impacting these women's ability to be healthy and live their life as they want to," said Kimberleigh J. Smith, senior director for community health planning and policy at the Callen-Lorde Community Health Center in New York, one of the country's largest LGBTQ centers, and coauthor of the letter. The companies acknowledged its receipt but nothing more. The shortage was originally projected to end in October 2016, but neither the companies nor the FDA has given any revised estimate of when supplies will ship.

What Smith and others stress is that despite there being alternatives to injectable estrogen, any uncertainty in the availability of what sustains the gender-affirmation process puts the mental health and well-being of this already vulnerable population at risk.

"I guess I feel fine," said Sarah O'Neill, 49, a transgender woman truck driver who lives in Bensalem and switched to pills. She said she hasn't seen any physical difference, but she can't shake a nervous feeling that they aren't really working. "I'm constantly worrying," she said.

Mazzoni's Morrison said this is not uncommon. "This shortage can be a really big trigger," she said. Morrison is concerned that trans women "will not just feel gender dysphoria again" — the sense that their outward appearance does not match their true identity — "but also go into hiding."

Vietro says the worry is justified. She said that the fear she felt that day in June was familiar, reminiscent of when life was unbearable. "I remembered that place I was mentally," she said. "I still remember how much I hated how I looked."

Vietro said she knew she was in the wrong body starting at age 3. Her parents took their then-son to a therapist, who said the child was just confused.

The relief of leaving home for college in Florida was short-lived. Vietro turned to alcohol and drugs. She became suicidal, she said on a recent afternoon at a café in Philadelphia's Gayborhood. She pushed her long, blond hair off her shoulders and pulled up her sleeves, running her fingers along her wrist scars.

In 2011, Vietro realized she was on the precipice and returned home to get help. She called Mazzoni, a nationally respected LGBTQ center that draws patients from around the country. "I can't be in this body," she recalled saying during her first appointment. "It's been wrong my whole life and I'm not going to make it much more." A week later, in early 2012, she started her gender-affirmation process.

Even now, Vietro sees in the mirror everything she wishes she could change. She said she's gone on more than 20 job interviews in recent months but has had no offers.

She longs for the “wave of relief” that comes with the estrogen injection that feels just right for her body. “It’s just like if you are sick and you need to get an antibiotic,” said Vietro. “This is not a choice.”