Botox was originally developed to treat strabismus, a condition where the eyes are misaligned and point in different directions. In the 1970s, an ophthalmologist named Alan Scott began injecting tiny amounts of botulinum toxin into the eye muscles of patients as a nonsurgical way to correct crossed eyes. The FDA formally approved it for this use in December 1989, and its cosmetic applications weren’t discovered until years later.
From Poisoned Sausages to Medicine
The story of Botox starts with food poisoning. In 1817, a German physician named Justinus Kerner published the first detailed clinical descriptions of botulism, a deadly illness caused by toxins in spoiled sausages. He documented 155 cases in remarkable detail, noting that the toxin shut down nearly every moisture-producing system in the body: saliva stopped flowing, tear ducts dried up, and the throat became, in his words, “a dead and motionless tube.” Kerner attributed the illness to a toxic substance in the meat, which he called “fatty acid.”
What Kerner had identified, without the tools to isolate it, was one of the most potent biological substances on Earth. The toxin works by blocking the chemical signal that tells muscles to contract. Nerve endings normally release a messenger molecule that triggers muscle movement; botulinum toxin almost completely shuts down that release. The result is targeted muscle paralysis. That same property that made the toxin so dangerous in contaminated food turned out to be extraordinarily useful when applied in microscopic, controlled doses to specific muscles.
Alan Scott and the Crossed-Eye Problem
In the early 1970s, Dr. Alan Scott was looking for a way to treat strabismus without surgery. The standard approach involved cutting and repositioning the small muscles that control eye movement, but Scott wanted something less invasive. He needed a substance that could selectively weaken a single overactive eye muscle, letting the eye drift back into alignment on its own.
He tested botulinum toxin type A on rats, mice, and cats before moving to monkeys, where injections into the eye muscles produced exactly the effect he was hoping for. Over a few days, the targeted muscle weakened, the eye shifted position, and the paralysis was highly localized with no apparent toxicity spreading through the body. He published those results in 1973, then spent the next decade running clinical studies in human patients. By the early 1980s, the data on safety and effectiveness was strong enough to pursue regulatory approval.
The FDA approved the drug (then called Oculinum) on December 29, 1989, for treating strabismus in patients 12 and older. One day later, on December 30, it also received approval for blepharospasm, a condition where the eyelid muscles spasm uncontrollably, sometimes forcing the eye shut for minutes at a time. Both conditions involve muscles that are overactive or misfiring, which made them natural targets for a toxin that quiets muscle activity.
How Wrinkle Reduction Was Discovered by Accident
The cosmetic use of Botox wasn’t planned. In 1987, a Canadian ophthalmologist named Jean Carruthers was using botulinum toxin to treat patients with eyelid spasms when one of her patients made an offhand observation: “When you inject my forehead, my wrinkles go away.” Carruthers mentioned this to her husband, Alastair, a dermatologist who treated patients with cosmetic concerns. She told him she thought she had something for his frown line patients.
The couple began studying the effect systematically. In 1992, they published a paper showing that 16 out of 17 patients with deep frown lines between the eyebrows saw visible improvement after injections, with results lasting anywhere from 3 to 11 months. That paper launched what would become the most recognizable cosmetic procedure in the world, but it took another decade for the FDA to formally approve Botox for cosmetic use.
Medical Uses That Followed
Between its original eye-related approvals and the cosmetic boom, Botox quietly accumulated a long list of medical applications. The same muscle-relaxing mechanism that corrected crossed eyes turned out to help with a surprisingly wide range of conditions.
- Cervical dystonia: a painful condition where neck muscles contract involuntarily, pulling the head into abnormal positions. Botox injections reduce the severity of both the abnormal posture and the neck pain.
- Chronic migraine: for people who experience 15 or more headache days per month, with headaches lasting four hours or longer, Botox injections around the head and neck are used as a preventive treatment.
- Upper limb spasticity: after a stroke or brain injury, arm and hand muscles can become rigidly tight. Botox loosens them enough to improve movement and comfort.
- Severe sweating (hyperhidrosis): when antiperspirants aren’t enough, Botox injections into the underarm skin block the nerve signals that trigger sweat glands.
In every case, the principle is the same one Alan Scott relied on in the 1970s: deliver a tiny dose of toxin directly to the tissue causing the problem, weaken the overactive nerve signals there, and let the effect wear off naturally over several months. What changed over the decades wasn’t the mechanism but the imagination of the doctors using it. Each new application came from a clinician noticing that a targeted muscle relaxant might solve a problem no one had thought to treat that way before.