Q & A Library

Collagen injections, the older of these two cosmetic procedures, involve use of a liquid made from the connective tissue, usually from cows to fill in wrinkles and acne scars. The biggest risk of this procedure is an allergic reaction to this material. About three percent of the population is allergic to bovine collagen, so everyone who is considering the injections must be tested. This is done -- at least four weeks before treatment - by injecting a small amount of collagen into the forearm and watching to see if a reaction develops. Unfortunately, the test isn't perfect: some patients who don't react to the test still have allergic reactions to the treatment.

You generally need a series of collagen injections until you get the cosmetic effect you want. Results last from three to 12 months.

Botox (Botulinum Toxin) injections are so popular these days that some doctors throw "Botox parties" at which they inject a group of friends at the same time at someone's house or in a hotel banquet room. More than 1.1 million Americans had Botox injections in 2002, making it the top non-surgical cosmetic procedure. Unlike collagen which fills in wrinkles, Botox works by paralyzing facial muscles, thus smoothing out frown lines (between the eyes, especially) for up to 120 days. Then you need more Botox.

Although Botox is the same bacterial toxin that causes lethal food poisoning, there's no danger of getting botulism from the shots. However, the procedure is not risk-free. If too much toxin is injected or injected into the wrong areas, you can end up with droopy eyelids that will stay that way for weeks. Other common side effects are headaches, respiratory infections, flu-like syndromes and nausea. Less frequently reported adverse reactions include pain in the face, redness at the injection site and muscle weakness. While these reactions generally are temporary, some cases have lasted for several months.

If you're interested in either of these procedures, be sure to check the credentials of the physicians you're considering. I would recommend seeking out a physician who is board-certified in plastic surgery or dermatology with experience in the procedure you want.

Andrew Weil, M.D.