How Botox Works

Botox is onabotulinum toxin A, related to the bacterial toxin that produces muscle paralysis and other effects of botulism. There are currently three types of botulinum toxin on the market in the United States, but most clinical experience has been with Botox® Cosmetic. Its clinical application began in the 1980s, when ophthalmologists began to use it to treat various disorders of eye muscles; it was approved for treatment of moderate to severe frown lines (glabellar lines) by the Food and Drug Administration in 2002. Botox administration has since then been one of the top five cosmetic procedures performed each year, and is now also approved for certain kinds of headaches, movement disorders and other neurological conditions and is the subject of study in other areas as well.

In addition to glabellar or frown lines, Botox is used for furrows and frown lines and in the forehead. Practitioners of anti-aging and cosmetic medicine had for some years treated crow’s feet with Botox in an “off-label” fashion, but the FDA fully approved the use of Botox for crow’s feet at the end of 2013. Other conditions for which Botox treatment is now approved include migraine and chronic tension-type headache, urinary incontinence from spinal injury and multiple sclerosis, abnormal muscle tone and spasms (spasticity), excessive underarm perspiration, speech disorders due to spasmodic contraction of the vocal cords and overactive urinary bladder. The possible utility of Botox is being investigated in osteoarthritis of the knees and hip, benign enlargement of the prostate, temporomandibular joint (TMJ) disorders causing facial pain, depression, essential tremor and premature ejaculation.

Cosmetic problems of the face have often been treated with collagen injection or soft tissue fillers that add volume to depressions in the skin. Wrinkles can arise from many causes, including collagen depletion and the effects of free radicals induced by sunlight, lifestyle and various toxins. Concentration and frowning are also responsible for furrows and folds in the skin between the brows, and squinting for whatever reason causes muscles around the eyes to contract and results in crow’s feet. Botox works by blocking the transmitter acetylcholine, which causes muscle contractions including those of the facial muscles responsible for wrinkles. This muscle paralysis is responsible for the symptoms of botulism, and is the reason why botulinum toxin should only be given in medical settings by trained professionals, but under safe conditions it paralyzes muscles for three months or more, with effects on wrinkles that are usually evident within a week. Some recent studies suggest that the prescription zinc supplement Zytaze can extend the duration of muscle paralysis and beneficial effects on wrinkles if given in the days before Botox injection.

Botox is given by injection, sometimes preceded by the application of ice, local anesthetic or a numbing cream depending upon the number of injections which need to be given. Extremely small-gauge needles are used to inject into the skin, so discomfort is usually minimal. Injection points are preselected and usually marked on the skin, and the injection usually takes 20 minutes or less. Crow’s feet are usually addressed by injecting 3 sites on the orbicularis oculi muscle at the side of each eye. Frown lines are treated with 5 injections, 1 in the procerus muscle at the top of the bridge of the nose and 2 in each corrugator muscle, located over the eyebrows. There are usually no or very few adverse effects, and most people can resume their normal activities immediately, although caution is sometimes recommended about going out in the sun.

Rare headache, soreness and redness at the injection sites have occurred after Botox injection. Muscle weakness, in particular drooping of the upper eyelid muscles, has also rarely occurred and lasted days to months. Very rare but potentially serious reactions involving paralysis of swallowing and breathing have been reported with spread of the botulinum toxin from the sites of injection, but these have been in situations where relatively large doses were given at multiple sites for reasons other than cosmetic treatment. The FDA requires that the different types of botulinum toxin carry a “black box” warning to inform patients and doctors of this risk, but it considers the cosmetic use of Botox to be safe.

Botox represents a major breakthrough in the treatment of wrinkles, frown lines, crow’s feet and other facial manifestations of the aging process. It should be done in medical settings by physicians familiar with the anatomy of the face and with techniques of facial injection, and should be considered as part of a comprehensive anti-aging program involving medical interventions and wellness programs for optimal health. These are areas where anti-aging medicine physicians can be of particular assistance.