Alastair Carruthers, 79, Dies; Pioneered the Cosmetic Use of Botox

“Pretty Poison,” newspapers called it in the mid-1990s, when the deadly neurotoxin that causes botulism began to make headlines as a temporary wrinkle-eraser.

Botulinum toxin was 100 times more virulent than cyanide. For years beginning in World War II, the Defense Department had hoped to develop it as a chemical weapon. But decades later, when Dr. Alan Scott, an ophthalmologist, refined it into a pharmaceutical after discovering its potential to cure conditions like strabismus (crossed eyes) and blepharospasm (involuntary eyelid twitching and clenching), an unlikely byproduct of his treatments was cosmetic: brows as smooth as a child’s.

Yet it was not Dr. Scott who pioneered Botox, as it would later be called, as a panacea for aging. It was Dr. Alastair Carruthers, a Canadian dermatologist, and his wife, Dr. Jean Carruthers, an ophthalmologist, who joined forces to investigate its cosmetic use in hundreds of peer-reviewed studies.

While Dr. Scott would come to be known as the “Father of Botox,” the Carrutherses were considered its godparents.

Dr. Alastair Carruthers died on Aug. 19 at his home in Vancouver, British Columbia. He was 79.

Dr. Carruthers, who had advanced Parkinson’s disease, died with the help of Canada’s medical-assistance-in-dying law, his wife said.

In the early 1980s, when skin cancer rates were rising precipitously, Dr. Carruthers left Vancouver to begin a fellowship at the University of California, San Francisco, in Mohs surgery, a technique, new at the time, for treating it.

Dr. Scott, who died in 2022, was also based in San Francisco, and Dr. Jean Carruthers applied for a fellowship to join his botulinum studies. The couple had three young children and didn’t want to be separated. When the Carrutherses returned to Vancouver, she continued Dr. Scott’s work. One day, one of her study subjects complained that the smooth forehead she had been accustomed to seeing after her botulism treatments hadn’t materialized in one instance.

“‘You didn’t treat me here,’” Dr. Jean Carruthers recalled the woman saying as she pointed to a spot just above her brow. “‘Every time you treat me here I get this lovely untroubled expression.’”

“Then the penny dropped,” Dr. Jean Carruthers said, and over dinner that night she proposed that she and her husband begin studying the brow-smoothing effects of the botulinum toxin. At the time, her husband was treating the frown lines of his cosmetic patients with substances like their own fat or bovine collagen, neither of which was ideal. Once the patient frowned, the lines returned.

The couple’s receptionist, Cathy Bickerton Swann, then 30, was their first subject. She had had a furrowed brow — a deep V etched above her eyebrows — since she was 12. She was not bothered by it, by her own account, but she was game for the experiment.

As Dr. Jean Carruthers explained, for years Ms. Swann had been seeing blepharospasm patients pass through the office and noting how their botulinum treatments had not only relieved their often crippling symptoms — some spasms were so severe, the patients were unable to drive or work — but also smoothed their faces. Ms. Swann felt secure that the treatment was safe and welcomed her role as “patient zero.” One injection wiped her forehead clean.

The Carrutherses’ first peer-reviewed study, of the so-called elevens, or frown lines — in anatomical terms, the glabellar lines — involved 18 patients. Before they started, Dr. Alastair Carruthers injected his wife, so that she could model the procedure.

As she often said, “I haven’t frowned since 1987.” Soon after, her husband followed her example. In photos throughout the decades, his brow remained as smooth as hers.

That first study “worked like a hot dime,” Dr. Jean Carruthers said. “It was spectacular.” She eventually closed her ophthalmology practice, trained in cosmetic surgery and joined her husband in his dermatology practice.

The couple went on to conduct hundreds of studies. After the glabellar lines, they focused on the frontalis muscle, which can produce horizontal lines on the forehead. Then they tackled the orbicularis oculi, which causes crow’s feet; the orbicularis oris, responsible for the vertical lines above and below the mouth; the mentalis, a chin muscle that helps in pouting, a wrinkle-maker; and the platysma, which stretches from the collarbone to the jaw and, when contracted, causes neck wrinkles and a loose jawline.

The Carrutherses, of course, were not the only doctors offering Botox for what was then an off-label use. Patients everywhere were clamoring for the stuff, even as some pundits decried its use as a sop to vanity in an ageist culture. Movie directors complained that actors were losing their ability to emote; lawyers trumpeted it as an aid to retaining a poker face, a boon in negotiations.

Soon, sketchy doctors emerged, often deploying bootleg Botox that mangled expressions and even paralyzed faces. “Frozen face” replaced “Pretty Poison” in the tabloid headlines. Politicians like John Kerry were scrutinized for Botox use (he denied it); during the 2004 presidential election, some reporters even tried to trick him into a scowl.

Skilled practitioners like the Carrutherses refined their technique to target more areas more precisely, augmenting Botox treatments with other substances, like dermal fillers, and Botox-outing became more difficult.

After a few decades, Botox use was no longer something to lie about, nor was it only for movie stars, politicians and the well-heeled. An unlined face became a badge of professionalism, a must-have for high achievers. Botox entered the self-care routines practiced by twentysomethings. More hand-wringing ensued. Botox had morphed into a multibillion-dollar global industry.

“The worst complication of Botox treatment is reduced expressivity,” Dr. Carruthers told Maclean’s magazine in 2014. “In the early days we were interviewed with a psychologist who tore into us for our promoting the McDonaldization of North America, reducing expressivity — that everyone’s going to be wandering around looking like a zombie. We felt bad for a week or two until we suddenly realized that he had it 100 percent wrong: When we do it right we help people better express themselves; they’re not looking angry/worried/stressed when they’re not angry/worried/stressed. Most people are quite happy to reduce their ability to frown; if they need to express compassion, they can tell people how they feel.”

James Alastair Carruthers was born on June 4, 1945, in Bebington, England, one of three children of Barbara (Brownless) Carruthers and Dr. Benjamin Carruthers, a family physician. Alastair attended medical school at Brasenose College, Oxford, graduating in 1968. He trained in internal medicine in Vancouver and Liverpool, and in dermatology at St. Thomas’s Hospital and St. John’s Hospital for Diseases of the Skin in London.

He met Jean Elliott when he was training in Vancouver at the University of British Columbia, where she was a medical student. They married in 1973.

Dr. Carruthers retired in 2015 and went back to the University of British Columbia as an undergraduate, studying European and Middle Eastern history. He could wield a scalpel, his wife said, but struggled with taking notes on a computer: “He didn’t have the typing skills of the average 18-year-old.”

In addition to his wife, Dr. Carruthers is survived by his sons, Thomas, Robert and Graham; his sisters, Gail Cosbie-Ross and Bobbie Lintott; and four grandchildren.

In 1991, Dr. Scott sold the rights to his refined botulinum product, which he called Oculinum, to its distributor, Allergan, for an undisclosed sum, after which the company changed its name to Botox. As for the Carrutherses’ fortunes, “we were babes in the woods in terms of patents,” Dr. Jean Carruthers said. When they first begin their work, they were turned away by two patent lawyers who said, as she recalled, “Well, what you’re doing isn’t that different from the work on blepharospasm; it’s not patentable.”

Terrible advice, she noted.

In 2002, the Carrutherses received a single-use patent for their work showing the effects of Botox on the depressor anguli oris muscles, which can cause the mouth to frown. They sold the patent to Allergan for $100,000.

In 2023, global net revenues from Botox Cosmetic were $2.7 billion, up from $1.6 billion in 2021, according to AbbVie, the company that acquired Allergan in 2020.

For her part, Ms. Swann, the former receptionist, told Newsweek in 2002 that she let her forehead return to its natural state after a half-dozen or so injections.

“Lifestyles change,” she said, “I’m 45 now, and married. I’m a little chubby, and I have gray hair. And I have the line.”