The promise of a more youthful look can be too tempting for a 55 year old person to resist. When the Food and Drug Administration approved a product that temporarily improves the appearance of frown lines between the eyebrows, people decided to give it a whirl and it wasn't long before there was a line of frequent flyer patients. The injection sessions often come with all the trimmings, including refreshments and friendly conversation.

Botox is a protein complex produced by the bacterium Clostridium botulinum, which contains the same toxin that can cause food poisoning. When used in a medical setting as an injectable form of sterile, purified botulinum toxin, small doses block the release of a chemical called acetylcholine by nerve cells that signal muscle contraction. By selectively interfering with the underlying muscles' ability to contract, existing frown lines are smoothed out and, in most cases, are nearly invisible in a week.

Botox injections are the fastest-growing cosmetic procedure in the industry, according to the American Society for Aesthetic Plastic Surgery (ASAPS). In 2001, more than 1.6 million people received injections, an increase of 46 percent over the previous year. More popular than breast enhancement surgery and a potential blockbuster, Botox is regarded by some as the ultimate fountain of youth.

Botox was first approved in 1989 to treat two eye muscle disorders--uncontrollable blinking (blepharospasm) and misaligned eyes (strabismus). In 2000, the toxin was approved to treat a neurological movement disorder that causes severe neck and shoulder contractions, known as cervical dystonia. As an unusual side effect of the eye disorder treatment, doctors observed that Botox softened the vertical frown (glabellar) lines between the eyebrows that tend to make people look tired, angry or displeased. Until this improvement was actually demonstrated in clinical studies, Allergan Inc., of Irvine, Calif., was prohibited from making this claim for the product.

By April 2002, the Food and Drug Administration (FDA) was satisfied by its review of studies indicating that Botox reduced the severity of frown lines for up to 120 days. The agency then granted approval to use the drug for this condition.

The FDA regulates products, but not how they are used. Approved products are sometimes used by a licensed practitioner for uses other than those stated in the product label. Botox Cosmetic, for example, is currently being used by physicians to treat facial wrinkles other than those specified by the FDA. Consumers should be aware, however, that this "off-label" use has not been independently reviewed by the agency, and the safety and effectiveness of Botox injections into other regions of the face and neck, alone or in combination with the frown-lines region, have not been clinically evaluated.

THE F.D.A. said, "Careful deliberation, investigation, and evaluation is undertaken by the agency before any prescription product is approved." Drugs such as Botox, which are not indicated for serious or life-threatening conditions, "are subject to a greater level of scrutiny because of the benefit-to-risk ratio."

The FDA is concerned that Botox has the potential for being abused. The ASAPS recently reported that unqualified people are dispensing Botox in salons, gyms, hotel rooms, home-based offices, and other retail venues. In such cases, people run the risks of improper technique, inappropriate dosages, and unsanitary conditions. "Botox is a prescription drug that should be administered by a qualified physician in an appropriate medical setting," says Toombs.

The F.D.A. went on to say, "Patient safety has to be of prime concern," he says. "People need to be in the right hands when complications arise." That's why we do not allow our staff to administer Botox treatments. Even the most skilled health-care providers, he says, can have complications as well as dissatisfied customers.

Although there is no chance of contracting botulism from Botox injections, there are some risks associated with the procedure. If too much toxin is injected, for example, or if it is injected into the wrong facial area, a person can end up with droopy eyelid muscles (ptosis) that could last for weeks. This particular complication was observed in clinical trials.

Other common side effects following injection were headache, respiratory infection, flu syndrome, and nausea. Less frequent adverse reactions included pain in the face, redness at the injection site, and muscle weakness. These reactions were generally temporary, but could last several months.

While the effects of Botox Cosmetic don't last, people don't seem to mind repeating the procedure every four to six months in order to maintain a wrinkle-free look. Battling the signs of aging in a non-invasive way, after all, is part of the allure of the product-- that and the fact that there are no unsightly scars, and there is very little recovery time with the procedure.

The FDA recommends that Botox Cosmetic be injected no more frequently than once every three months, and that the lowest effective dose should be used.