In the crowded landscape of botulinum toxin products, Botox continues to maintain its position as the undisputed market leader in the botulinum toxin segment.

In 2024, AbbVie reported global Botox revenues of approximately $2.7 billion in aesthetics and $3.2  billion in therapeutic use -- totaling about $6 billion, or roughly 11 percent of the company’s overall revenue .

Such figures reflect Botox’s dual identity as both a cultural household name and a clinical cornerstone across multiple medical specialties.

But according to Dr. Mitchell Brin, Senior Vice President of R&D and Chief Scientific Officer for Botox and neurotoxins at Allergan, the secret to this enduring dominance goes far deeper than brand recognition -- it's rooted in decades of groundbreaking science and an unwavering commitment to patient care.

Notably, while the brand name Botox may evoke images of wrinkle-smoothing procedures in dermatology clinics, its clinical reach stretches far beyond aesthetics. In fact, Allergan’s flagship botulinum toxin -- approved for over 16 indications globally -- has transformed how doctors approach a range of serious, often debilitating, neurological and urological conditions.

Brin, who also serves as a clinical professor of neurology at the University of California Irvine, brings a unique perspective that bridges cutting-edge research with real-world patient care.

In an interview with Korea Biomedical Review, Brin shared insights from over three decades of neurotoxin development, highlighting how the science has evolved, where resistance concerns stand, and what the future holds for Botox as both an aesthetic and drug platform.

A foundation built on firsts

Allergan was the first to bring botulinum toxin type A to the U.S. market in 1989 for ophthalmologic uses, and since then, Botox has gained approval for a wide range of therapeutic and aesthetic indications.

“We were the first to develop nearly every neurotoxin indication that’s been approved,” Brin said. “That means we created all of the development pathways, and that gave us a huge head start in understanding both efficacy and safety.”

Therapeutic indications now include cervical dystonia, spasticity (adult and pediatric), chronic migraine, axillary hyperhidrosis, overactive bladder, and neurogenic detrusor overactivity, among others.

“These are not niche diseases -- they are widespread, high-burden conditions that severely affect patients’ daily lives,” he said.

Notably, before Botox’s approval in 2010 for chronic migraine, the condition lacked clear clinical boundaries. According to Allergan’s internal PREEMPT trials, there was no universally accepted distinction between episodic and chronic migraine.

“Our development program helped define chronic migraine as distinct from episodic migraine,” he said. “That classification didn’t really exist before -- it changed how the medical community thinks about migraine as a spectrum.”

At the core of Allergan’s strategy is what Brin calls a “global but patient-centered” approach.

“We recognize regional treatment preferences,” he noted. “For example, masseter treatment is in especially high demand in Asian markets, and we were the first to gain approval for that indication in China.”

But whether the application is therapeutic or cosmetic, Brin insists that Botox’s consistency is rooted in rigorous manufacturing control and global physician education.

“We train doctors extensively -- not just how to inject, but whom to treat, and how to set expectations,” he said. “That’s what ensures consistent patient outcomes, whether in the U.S., Korea, or Latin America.”

Even as Botox is increasingly used in combination with other interventions -- like hyaluronic acid fillers in aesthetic clinics or oral CGRP inhibitors in migraine therapy -- Brin views this multimodal integration as a strength, not a threat.

“Patients are already combining modalities in the real world,” he said. “We study these patterns and use them to define best practice, not resist it.”

Consistency, resistance, and responsible dosing

Despite emerging competition, such as Jeuveau (Daewoong), Letybo (Hugel), Dysport (Ipsen), and Xeomin (Merz) -- Botox remains the benchmark due to its manufacturing consistency and comprehensive education programs. Clinic-to-clinic outcome stability is ensured through standardized training and tightly controlled production.

“The consistency of our product starts with our manufacturing technology,” he said. “Our processes are very tightly controlled, and that gives the product a high level of consistency.”

But consistent outcomes don’t come from the vial alone.

Allergan invests heavily in global physician training programs to ensure that Botox is administered properly, regardless of geography or indication.

According to Brin, these programs are designed not just to teach injection technique, but also to help doctors understand patient selection, product science, and treatment planning.

“We train people how to use the product appropriately,” he said. “We train them about the science of the product, how to administer it, and how to select patients who are most likely to achieve benefit.”

That’s what leads to consistent treatment outcomes, and everything about medicine is really about outcomes, he added.

He also noted that when used properly, Botox produces reliable effects across diverse populations.

“When we’ve looked at Caucasians, Asians, and other groups, the results are quite consistent across geography,” Brin said. “That allows us to use a standardized training approach globally.”

Addressing the resistance challenge

As Botox use has expanded, concerns about resistance development have grown.

Brin takes this issue seriously, particularly for therapeutic patients requiring lifelong treatment. Recent research from Allergan's comprehensive database -- the world's largest immunogenicity study involving nearly 30,000 samples -- provides reassuring data.

"When you look at the entire population and the incidence of antibodies or neutralizing antibodies at the end of trials, it was 0.3 percent," Brin reports. Even more encouraging, many patients with detectable neutralizing antibodies still responded to treatment.

The risk appears dose-dependent, with no antibodies detected in aesthetic studies or chronic migraine studies using up to 195 units.

"The area of concern is higher doses," Brin acknowledges, emphasizing the importance of using appropriate dosing protocols.

Expanding the platform: innovation beyond type A

While Botox type A continues to dominate, Allergan is now developing a new formulation: botulinum toxin type E, which may become the first new neurotoxin serotype approved in over two decades.

Unlike type A, which offers a longer duration of action, type E has been designed for rapid onset and shorter duration -- attributes that could appeal to new users who are hesitant about long-lasting results.

“Type E gives patients an opportunity to experience the benefits of botulinum toxin without committing to a long duration,” Brin explained. “It opens the door to a new category of aesthetic patients.”

The company has already submitted type E for regulatory review in the U.S., and its approval could mark a strategic expansion of the neurotoxin category into more customizable, short-acting interventions.

Real-world data and digital health integration

To stay ahead of evolving clinical needs, Allergan is also integrating artificial intelligence and real-world evidence into its R&D processes.

The company is leveraging over 35 years of global clinical data -- much of it from Botox itself -- to inform everything from safety modeling to treatment optimization.

“There is an abundance of data available,” Brin said. “Using AI helps us mine our own history, whether it's understanding how Botox works in combination with other treatments, or refining dosing strategies based on actual patient outcomes.”

This includes evaluating how Botox is used alongside hyaluronic acid fillers in cosmetic clinics, or with CGRP inhibitors like atogepant in migraine care.

“What we see in real-world studies is that many of these combinations offer additive benefits because they work through different mechanisms,” he added.

A platform grounded in science and human need

Brin, who still volunteers once a month as a clinical neurologist, concluded that Botox is not just a product but a scientific and therapeutic platform -- one that spans diverse specialties and patient demographics.

“We’ve seen children with cerebral palsy walk more easily, stroke survivors regain arm mobility, and migraine sufferers reclaim their daily lives,” he said. “Even in aesthetics, we’ve documented real improvements in self-esteem and mental health.”

These aren’t superficial gains; they are meaningful to people’s lives, he added.

He also highlighted the social value of predictability and physician trust.

“Clinicians know what to expect from Botox,” he said. “That’s not just about branding -- it’s about decades of safety, consistency, and outcomes.”

As the neurotoxin market becomes increasingly competitive and complex, Brin sees Allergan’s role as both steward and innovator -- preserving the reliability that made Botox a global standard, while pushing into new frontiers of patient care.

“If someone tells me Botox gave them their life back, whether that’s physical function, emotional confidence, or freedom from pain, that’s when I know we’re on the right path,” he said.