Botulinum toxin (Botox) is the same toxin that causes a disease called botulism. Botox injection improves some of the cosmetic problems which are caused by muscle contractions.
Mechanism of action of this substance is related to different type of this toxin and mostly toxins A is used clinically for cosmetic purposes.
Botox injection weakens and paralyzes muscles temporarily and it will be back in couple of months, thereby it can be used in cosmetic purposes and rejuvenation.
It can be used for cosmetic purposes such as:
Frown lines
Horizontal creases in the forehead
Wrinkles around the eyes, known as crow’s feet
Droopy lids
Top of the nose (bunny lines)
Radial lip line
Lipstick lines (vertical Lip lines)
Droopy nasal tip
Nasal labial folds (Nasolabial folds)
Smile lines
Neck lines
Marionette lines

In these cases Botox should not be injected:
Infection in injected area
Being Allergic to the components
People who are allergic to cow’s milk protein
Prohibition of relative use in neuromuscular diseases
Myasthenia gravis
Myopathies
Drug usage such as aminoglycosides or cholinesterase Inhibitors
Pregnancy
There is no sufficient information about the prohibition while breastfeeding.

Botox side effects:
Pain in the injected sites which will be resolve within few hours
Bruising which will be resolved within few hours up to few days depending on skin type.
Droopy eyelids, if it happens it will automatically resolved within 2-12 weeks

Quizzical look which can be modify through re-injection treatment.
Botox effects:
It will begin working within 48 hours after injection and final result will reveal after 2 weeks.

Botox injection after care
Avoid to lying down, bending the head or washing injected areas for 8 hours.
Avoid getting messages in injected sites for 3 days.
Avoid smoking and heating for 1 week.
Avoid lying on the face for 3 days.