Botulinum Toxins

What is botulinum toxin (Botox)?


Botulinum toxin, also known as BTX or commonly as the trademarked product Botox, is a neurotoxic protein that is produced by the bacterium Clostridium botulinum. BTX is currently the most lethal toxin known, with different strains producing a total of eight distinct neurotoxins—named Types A through H. While scientists have been able to harness some of these types for commercial and medical use, many of the types produce disease in humans and animals, possibly leading to death. Botulinum toxin targets the nervous system and can prevent muscles from contracting, resulting in weakness or paralysis of the muscle. The results of this paralysis can prove deadly if the toxin infects parts of the nervous system that provide vital functions, such as the chest. If the muscles in the chest are unable to move then breathing is restricted; so, if paralysis of the respiratory muscles occurs, it will be impossible to breathe.


What is clostridium botulinum?


Clostridium botulinum is a gram-positive, rod-shaped bacterium that can be found throughout the world, typically in soil. This bacterium is responsible for producing botulinum toxin, which is the most lethal toxin in the world. Clostridium botulinum grows best in environments with low or no oxygen, and forms spores that can withstand boiling temperatures. The toxin is only formed in low oxygen (anaerobic) conditions, meaning that the spores rarely cause problems as the conditions for growth do not easily occur naturally. For the most part, Clostridium botulinum is inactive and non-toxic. There are 8 types of botulinum toxins that are formed—Types A through H—and though some of these types can be processed for commercial and medical use (sold under the name Botox, among others), 4 of these types (A, B, E, and F) are responsible for a potentially fatal type of food poisoning called botulism.


What is Botox made of?


Botox, also known scientifically as onabotulinum toxin A or botulinum toxin Type A, is a purified form of the bacteria botulinum toxin, and is the first bacterial toxin that has been manufactured for use as a medicine. Botulinum toxin was initially approved by the U.S. Food and Drug Administration (FDA) in 1989 to treat 2 different types of eye conditions. Since 1989, BTX has been approved for both medical and cosmetic use, with approval occurring in 2002 for treatment of frown lines and wrinkles in the face. While Botox is derived from the same bacteria that is known for its lethally poisonous qualities, this medical form of the bacterium is tightly regulated and safe, and the amount used for medical procedures is very small compared to the amount required to cause any amount of harm.


What is Botox used for?


Botox has many medical applications, though it is most often used for cosmetic purposes to reduce the appearance of fine lines and wrinkles in the face. Currently, BTX is used in the treatment of over 20 different medical conditions, with more uses being studied. Botulinum toxin is currently recognized as an approved treatment in 9 medical conditions in addition to its many cosmetic uses, and Allergen, the company that owns Botox, currently holds around 800 patents for potential uses of the drug. BTX is a neuromuscular blocker, and so its uses all align with its ability to paralyze a muscle upon injection. Its ability to treat a variety of medical conditions is due to the fact that muscle issues are a root problem in many conditions.


Some of the medical issues BTX is used to treat are:


For migraines


The use of Botox in the treatment of migraines was discovered by accident as a byproduct of other procedures. In the early 90s, a plastic surgeon conducting studies on the use of BTX for facial wrinkles noticed that many patients reported having fewer headaches. In 2010, Botulinum toxin was officially approved for use in helping to alleviate migraines. Certain muscular mechanisms have been identified as contributing to the development of migraines, and having the drug injected into a patient’s head and neck approximately every 12 weeks can help treat and prevent migraines.


For the bladder (incontinence)


BTX is also an accepted medical treatment for an overactive bladder. Patients suffer from this condition because their bladders squeeze too often or without warning, resulting in frequent urination or leakage. An injection of Botox will make the bladder relax, allowing the bladder’s storage capacity to increase, therefore reducing the instances of urinary incontinence. BTX has been found to be an effective treatment for patients who can’t use, or have found no success with, the commonly prescribed medication for this issue.


For the eyes


In addition to being able to treat and smooth wrinkles at the side of the eyes and in the under-eye area, Botox is also an approved medicine in the treatment of multiple conditions relating to the eyes. The very first time BTX was used as a medical treatment was in 1981 as a treatment for people with crossed eyes, a disorder known as strabismus. By injecting BTX into muscles that control eye movement, the appearance of crossed eyes is reduced. BTX is also an effective treatment for blepharospasm, which is the uncontrolled blinking or the narrowing or closing of the eyelid. It has also been approved for this treatment since 1989, and can be used for this purpose on patients 12 years and up. Another way Botox has been used around the eye is in attempting to achieve a widening of the eye by using advanced techniques that prevent muscles from tightening around the eye area.


For crow’s feet


Another of Botox’s most popular uses is in the treatment of crow’s feet—or more specifically, the wrinkles that appear at the corners of the eyes. An injection of BTX works to alleviate the fine lines and wrinkles in this area of the face by relaxing the muscles around the eyes that contract when a person smiles, laughs, or squints. When these muscles don’t contract, the lines do not appear as they normally would in an untreated face.


For eyebrow lifts


Medical practitioners with a thorough understanding of the underlying anatomy of the brow area are able to use BTX to lift and reshape eyebrows. Using advanced techniques, practitioners can use Botox injections to prevent specific muscles from pulling the brow down, resulting in the relaxation and elevation of the brow. This treatment focuses on five specific depressors: the procerus, the muscle that pulls down the brows to create the horizontal crease at the top of the nose; the right and left corrugators, which are the muscles that pull the brows inward and down; and the right and left orbicularis oculi, the muscles that encircle the eye that allow the lids to close tightly. Additionally, slight reshaping can result from targeting certain areas of the brow to create more height, for example creating a raised arched brow or a raised horizontal brow.


For sweating


Similar to how BTX started to be used as treatment for migraines, doctors realized the potential of Botox to help with excessive sweating after patients being treated for facial spasms noticed they were sweating less. Scientists started studying the effectiveness of this treatment, particularly in people suffering from a condition called primary axillary hyperhidrosis, and Botox was approved for the treatment of sweating in 2004. This treatment is successful because it targets the small muscles around the sweat glands which squeeze the liquid out, so when these muscles are paralyzed, the sweat glands do not function as they typically would.


For underarms (armpits)


For people who suffer from severe primary axillary hyperhidrosis, receiving BTX injections in the armpits may be the only effective treatment to cut back on excessive sweating. Though topical treatments are available, people who do not find success with these products may turn to Botox treatment. When injected into the skin of the underarm, the muscles that contract around the sweat glands and cause the secretion of the malodorous fluid are relaxed. This means that the sweat glands do not produce as much fluid, resulting in less sweating and less unpleasant odor. While Botulinum toxin is known to be effective in treating the underarms, it does not promise to help with sweating in any other areas, though doctors do use it on occasion to treat the hands and feet.


For wrinkles


BTX is most commonly known for its use in helping to alleviate and smooth wrinkles, particularly facial wrinkles, for cosmetic purposes. Wrinkles and fine lines are one of the primary signs of aging, and the reduction of these visible signs result in smoother, younger looking skin. When it comes to reducing the presence and severity of wrinkles, BTX works by temporarily stopping the nerve from activating the muscles responsible for wrinkling the skin, resulting in even, more toned looking skin.


For muscle spasms


With BTX’s ability to paralyze muscles, its use in the treatment of muscle spasms is a no-brainer. Before the FDA approved Botox for cosmetic treatment, it approved the formula for the treatment of various types of dystonia, or muscle spasms. By injecting BTX into a muscle that chronically or persistently contracts, the muscle becomes relaxed and the involuntary spasms no longer occur. Spasms in the neck, face, and eye, are all treatable with BTX.


For forehead lines (frown lines)


When it comes to using BTX as a treatment for facial lines, Botox was first approved specifically for use in the frown lines, officially known as the glabellar lines. These lines are the wrinkles that occur when a person raises their forehead muscles, resulting in horizontal lines on the forehead. As with the treatment of other facial wrinkles, this treatment relaxes the muscles that cause the lines to appear, preventing the skin from forming visible lines. This temporary treatment simply softens pre-existing lines, so many cosmetic medicine professionals suggest starting these injections early, so as to prevent the lines from becoming deeper as the skin ages.


For smile lines


When a patient seeks BTX treatment to soften the appearance of smile lines, they are usually concerned with the lines around the mouth. These lines appear when a person smiles and by targeting the muscles that contract under the skin to cause these lines, Botox can smooth the appearance of these lines when smiling occurs.


For hair


Anecdotal evidence suggests that BTX can be an effective treatment for thinning hair. By injecting Botox into the scalp, the muscles relax and blood flow is stimulated in these areas, helping to increase the delivery of nutrients to the hair. It is suggested that this will only produce results if the hair follicle is not entirely destroyed, so it may not be effective in instances of balding.


For acne


Unlike many of the other things BTX is used to treat, the treatment of acne focuses not on the muscles below the skin, but on the dermis itself. Doctors have started using Botox to treat acne by injecting it directly into the skin to slow oil production, eliminate large pores, and prevent acne breakouts. Studies suggest that when injected, BTX blocks the chemical acetylcholine, which is responsible for increasing the production of sebum (oil). When this chemical is blocked, it prevents the production of sebum and starves the bacteria in the skin that produces pimples.


Botulinum toxin types


There are, in total, 8 different types of botulinum toxin that are currently known by scientists, named Types A though H. Some of these types are sold commercially for use in cosmetics and medicine, while others can cause disease in humans and other animals. Types C through H are not very common, whiles Types A and B are the ones used in medical treatment.


Type A


Botulinum toxin Type A is one of the 8 types that is sold commercially for medical use. This type also goes by the generic name onabotulinumtoxinA, but would be most widely recognized by the brand name Botox, though other brands are available (Dysport and Xeomin). Botulinum toxin Type A is used medically and cosmetically in instances where a temporary paralysis of muscle activity will produce the desired results or solution to the issue being treated.


Type B


Botulinum toxin Type B is also one of the 8 types that are manufactured for commercial and medical use. This serotype is sold as Myobloc, or rimabotulinumtoxinB in its generic name, and has the same effect on muscle activity as Botulinum toxin Type A. Currently, Type B is only approved for use for a variety of pathologies related to muscle issues, and is not officially approved by the FDA for cosmetic use.


How long does it last?


Though the duration of the effects of treatment with BTX will vary by patient, it lasts on average 3 to 4 months, but may last up to 6 months in some individuals. There are many factors that will determine how long the effects last, including the dosage used, the duration and consistency of use, and the technique used to administer the injection. Typically, the effects start to last longer after repeat injections. Additionally, a patient’s age and lifestyle can play a role in the duration of the effect.


How does BTX work?


BTX works by blocking the signals from the nerve cell from communicating with the muscles, resulting in their paralysis. More specifically, BTX prevents the release of the neurotransmitter acetylcholine, which plays a huge role in causing the muscle cells to contract or shorten by acting as the chemical messenger between the nerve endings and the muscle cells. When acetylcholine is prevented from doing its job, then muscle cells are prevented from contracting. However, neurons are capable of generating new nerve endings, which means that the BTX treatment is always temporary.


How to inject BTX


BTX should only ever be injected by a licensed, experienced medical professional. The injection technique and dosage will always depend on the condition BTX is being used to treat, but will typically be injected either into the muscle of the treatment area, or into the skin. Depending on the treatment, needles in the size range of 22G to 30G should be used. It is important that the medical practitioner have an advanced knowledge of anatomy, particularly facial anatomy in the case of treatment for facial wrinkles and lines.


How to store BTX


Unopened vials of BTX should be stored in a refrigerator at 2° to 8°C and can be stored for up to 36 months for a 100 U vial, or up to 24 months for a 200 U vial. It should never be used past the expiration date marked on the vial. Once the BTX is reconstituted using a saline solution, it is recommended to use it within 24 hours, and should be stored in a refrigerator at 2° to 8°C.


What are the side effects?


There are mild common side effects associated with the use of BTX, though injections are usually well tolerated. As with all medical procedures, there is a risk of infection and a chance of allergy, and it is important for a patient to disclose their medical history to the doctor performing the procedure. On very rare occasions, BTX can spread to areas of the body that were not treated and cause severe side effects, of which a medical professional should be informed immediately.


Common side effects


  • Bruising, redness or pain at injection site
  • Headaches
  • Flu-like symptoms such as nausea and muscle aches
  • Muscle weakness near injection site


Severe side effects


  • Unusual or severe muscle weakness in area where there was no injection
  • Difficulty breathing, talking (hoarse voice), or swallowing
  • Loss of bladder control or painful urination
  • Chest pain or tightness, irregular heartbeats


How often should your patients get BTX?


The frequency of treatment will depend on the area being treated and the desired use, and should always be determined by a medical professional. However, patients should receive injections no more frequently than every 3 months. Many patients will need to get BTX less frequently the longer they are treated, though some patients very rarely may also develop antibodies to botulinum toxin, rendering the treatment ineffective.


BTX vs Dermal Fillers


While Botox and dermal fillers are both used in cosmetics to smooth the appearance of wrinkles to achieve a younger, more toned appearance, each of these injection types serves a different function. Botulinum toxin freezes the muscles that cause fine lines and wrinkles to appear due to certain actions (i.e. smiling, frowning, and squinting), so its primary function is not to plump up areas that have pronounced lines when the face is at rest. This is also why BTX is recommended for use much earlier, as it can help prevent the muscle contractions that cause lines and wrinkles to form in the long term. While a highly experienced practitioner may be able to use advanced techniques to get BTX to correct depressions even at rest, many would recommend the use dermal fillers for this purpose. Instead of treating wrinkles and lines by way of muscle activity, dermal fillers are injected into the dermis to fill in wrinkles and fine lines, adding renewed plumpness to the skin. Dermal fillers will typically replace volume in the dermis that has been lost due to aging or environmental factors. To put it most simply, Botox is used for lines of expression, while dermal fillers are used for lines at rest. Both Botox and dermal fillers are only temporary treatments, with BTX lasting around 3 to 4 months, while dermal fillers can last anywhere from 9 to 14 months depending on the type of filler used.




BTX is a safe, non-surgical and minimally-invasive way to treat a multitude of problems. Botox can be a solution to issues that are otherwise very difficult to treat, helping patients live a more comfortable and happier life. Botulinum toxin doesn’t have any long-lasting side effects, and results can start to manifest within the first 24–72 hours (though it may take 5–7 days for some individuals to see results). Another benefit for many patients is that the effects may last longer upon repeated use, making the time between treatments longer after continued use.