We’ll call her “Lisa.” She doesn’t want to tell the world that she and her husband, “Sam,” routinely have Dr. Michael Olding, chief of plastic surgery at George Washington University Medical Center, fill in their wrinkles.

Lisa and Sam exercise seven days a week. They eat carefully; both are trim. They do all they can to keep fit. “I can take care of my body, but Dr. Olding has to take care of my face,” Lisa says.

She is 61, and Sam is 70. People usually assume they’re each a decade or more younger.

Once a year, the two visit Olding so he can inject Restylane, Juvéderm, or Perlane to hold the clock at bay. These are trade names for three popular hyaluronic-acid fillers that plump out wrinkles. Sam and Lisa have tried all three; depending on what they’re having done, the doctor may use some of one and some of another.

Other fillers include Hylaform, Hylaform Plus, Sculptra, and Radiesse. Fillers differ in thickness and chemical composition. A good doctor will offer several options and ask about allergies before choosing one or more to use; some patients report allergic reactions, most commonly redness or swelling or bruising, to one filler but not another. Fillers also vary in how long they last, and a patient’s body chemistry affects that: The same filler may keep one person’s lines concealed for six months, while another gets eight months out of a treatment.

Lisa and Sam pay $600 to $650 per syringe used, which is the way these products are billed. Filling in the nasal-labial folds, the creases that run from the corner of the nose to the corner of the mouth as the face slackens, one syringe for Lisa. Sam’s cheeks are a bit sunken, so he needs two syringes there.

“Dr. Olding doesn’t just inject it,” Lisa says. “There’s an art to it. It’s moldable; he presses it with his fingers, moves it. He says that the thicker the injectable—some are thicker than others—and the deeper you can put it, the more natural-looking it is.”

On a recent visit, Lisa wanted filler in her lips. “The top one is starting to look a little thin,” she says. Although she hasn’t minded getting filler on other parts of her face, the needle to her lips hurt much more, even with a topical anesthetic.

Still, she’ll do it again. “It’s absolutely worth it,” Lisa says.

The American Society of Plastic Surgeons reports that from 2006 to 2007 injectable fillers jumped from being the fifth-most-frequent cosmetic procedure to the second. Fillers trail only Botox in popularity.

A good many of the patients trying both injectables and Botox, which temporarily relaxes a muscle so that it can’t contract and cause a wrinkle, are under 40 and coming in at the first sign of lines on their forehead or laugh lines around their eyes. “Start with it early enough and you’ll prevent getting some of the deeper wrinkles, and you may well put off the time when you’ll need a facelift,” says Olding.

The going rate locally is $400 to $750 for both sorts of injections. With the economic downturn, some doctors have been running specials on Botox and fillers.

If you hear of a clinic or spa that offers crazy low prices on Botox every day, beware. Botox is easy to dilute. Anyone with a medical license can inject patients or let others do it under his or her supervision.

“Botox is one of those things that looks simple and is not,” says Diane Colgan, a plastic surgeon in Potomac. “You have to know the anatomy of the face, know how much to use and where to place it.”

Botox can relax little wrinkles at the outer corner of the eye by stopping the muscles that allow you to squint. But a needle put in the teensiest bit off-target can make you live with a droopy eyelid for months. Regardless of where you plan to use Botox or a filler, unless you are sure a doctor has been using these a long time, you are safest in the hands of a plastic surgeon or a dermatologist—preferably one who often injects these drugs.

Calling the drug “Botox Cosmetic” is how doctors differentiate between botulinum toxin used to stop wrinkles and the same substance used to treat an ever‑growing list of maladies, including tics, muscle spasms, migraine headaches, and most recently, overactive bladders. So many uses are being found for Botox that it may turn out to be a wonder drug like aspirin and penicillin.

The Food and Drug Administration has approved using Botox to treat furrows between the eyebrows but nothing else on the face. The FDA hasn’t approved using Botox with a wrinkle filler, although doctors do it routinely. They also use Botox on marionette lines, which run from the ends of the mouth on down, and on the fine lines at the corners of the eyes and mouth. None of this is illegal. Once a drug gets a go-ahead for one use, it’s not uncommon for it to be used “off label” for something else. The FDA didn’t approve Botox Cosmetic until 2002, more than five years after Botox was a sensation for its cosmetic uses.

Reloxin, a new type of botulinum for cosmetic injections, is in the final stage of being approved by the FDA. If the agency gives the go-ahead, Reloxin could be on the market next fall. It already has been approved for use in 23 countries, including Argentina, Brazil, and Germany. The word is that Reloxin disperses into muscles more readily than Botox Cosmetic does, resulting in a more natural look.