Botulinum toxin injections (Botox) have been used in medicine since 1973 as a treatment for patients with crossed eyes.
By weakening the overactive eye muscles, Botox provided an alternative to surgery.
In the 1980s Botox began to be used for cosmetic procedures, such as neutralising overactive brow muscles causing permanent skin creases.
Since then Botox has been found to improve neck banding and, to a lesser degree, "crows feet".
Botox may also be used with laser resurfacing to help prevent a recurrence of crows feet.

Botox works by inhibiting the release of acetylcholine at the joining site of the nerve to the muscle.
This prevents the muscle from contracting.
Several areas can be injected simultaneously, but most doctors limit the amount of toxin injected at one time. Serious side-effects are uncommon.
The most common problem is temporary bruising.
In an American Academy of Dermatology study over 32 months, 509 patients bearing wrinkles localised at frontal, glabellar, orbital and cervical regions were selected for treatment, with a total of 1,200 applied areas.
A high muscle paralysis degree was reached with the consequent improvement of symptoms in practically all cases.
Only 17 patients needed reapplication before four months (3.3%).
The academy noted that the effects were noticed within 24-48 hours after injection, and were enhanced in up to seven or ten days, remaining stable for about four to six months.

 At the periorbital region, which is the most applied area, there was a significant increase of side portion of eyebrow, providing a more jovial aspect to the patient.

The patients ages ranged from 24 to 81 years, with the sample comprising 431 females and 78 males.

The academy concluded Botox to be a "simple, non-surgical, safe and effective method for treating wrinkles, mainly in the lower third of the face. "

It presents few complications, is reversible, may be reapplied several times and is easy to be obtained. 

In another study focusing on using Botox to treat the aging neck, 1,500 patients were in the care of three practices for 36 months.
Most patients had injections to the muscle cords in the bilateral anterior, the area from chin to notch between collar bones, or "turkey gobbler".
Eighty-four per cent of the patients were women, 16% were men, and the ages ranged from 30 to 77.
The best results appeared in patients with mild horizontal neck rhytids (lines). 98.5% had good-to-excellent results with 1.5% having fair results.
In a study on Botox in facial aesthetic procedures all 26 patients reported, at the very least, a small improvement. According to the study, the procedure is most appropriate for older patients who are not good candidates for surgery, older patients who have previously had neck rejuvenation surgery and younger patients with strong, dynamic platysmal bands who are not yet surgical candidates.
Although most of the patients were very happy with their results, Botox is not a replacement for surgery and definitely not a face-lift in a bottle.