Interest in plastic surgery is at an all-time high, but stigma and misinformation still surround the industry and patients. Welcome to Life in Plastic, a series by Allure that aims to explain cosmetic procedures and provide all the information you’ll need to make the decision that is right for your body — no judgment, just the facts. Here, we’re covering everything you need to know about fillers.

We hear it from experts every day: Cosmetic injections are not akin to haircuts and shouldn’t be approached with the same it’ll-grow-back attitude, since having prescription drugs and medical devices — as neurotoxins and fillers, respectively, are classified by the Food and Drug Administration — shot into one’s face can carry consequences far more serious than a botched bangs trim. But doctors’ crusades against being too cavalier about fillers is constantly receiving pushback. In Los Angeles, for instance, the hair analogy is being spun as a win by an injectables outpost dubbed the “Drybar of Botox,” which offers hyaluronic acid (HA) fillers (like Restylane and Juvéderm), neurotoxins (Botox and Dysport), and fat-melting Kybella, with a breezy-as-a-blowout, nothing-to-fear vibe.

Injectables are big business: Over two million people received botulinum toxin or filler injections in 2017, according to the American Society for Aesthetic Plastic Surgery. The popularity of temporary HA fillers, specifically, has soared 85 percent since 2012. And practitioners of all kinds — with varying degrees of training and experience — are capitalizing on the demand.

Consequently, doctors are seeing a dramatic rise in both complications (from fillers, in particular) and plain, old bad work. Beyond fixing her daily share of filler-related lumps and asymmetries incurred by other injectors, New York City dermatologist Shereene Idriss has more and more “patients coming in looking like caricatures of themselves — with disproportionately large lips and flattened nasolabial folds — due to misplaced filler injected by untrained practitioners,” she says.

And while some fillers can be dissolved with a quick shot, not all mistakes are so easily undone. “With every kind of filler, there’s the risk of unintentional injection into a blood vessel, which can result in skin death, scabbing, scarring, even blindness,” Idriss adds.

That said, fillers are generally very safe when injected by board-certified dermatologists and plastic surgeons armed with an intimate knowledge of human anatomy and “filler crash carts” stocked for potential complications. (Shoutout to New York City plastic surgeon Lara Devgan for sharing that gem of a term.) But this is merely rule number one of getting filler. Read on for everything experts want you to know before submitting to the syringe.

Not all fillers are created equal.

While the lion’s share of fillers in your dermatologist’s armamentarium are made of HA — a safe sugar found naturally in the human body — a few are made from other materials. Radiesse contains the mineral calcium hydroxyapatite (the stuff of teeth and bones, it’s visible in X-rays and CT scans). Sculptra uses poly-L-lactic acid (PLLA), a biodegradable man-made polymer — the same component in absorbable stitches. Bellafill suspends polymethylmethacrylate (PMMA), or nonbiodegradable acrylic beads, in cow-derived collagen, and “is essentially permanent,” says New York City plastic surgeon Paul Lorenc. (Technically, it’s FDA-approved to be safe and effective for up to five years.)

Unlike HA fillers, which basically serve as place holders — substitutes for depleted collagen and fat — these others are known as biostimulatory fillers: They give an immediate, short-term plumping “due to the simple fact that liquid is being injected into the face,” says Idriss, but their primary purpose is to spark the growth of your own collagen for longer-lasting fullness and lift. (By stimulating fibroblasts, HAs have also been shown to “ramp up collagen and elastin production over time,” though likely to a lesser extent, says Laurel Geraghty, a dermatologist in Medford, Oregon.)