Thanks to better techniques and scientific advances, dermatologists report a spike in people lining up to go under the needle. On the other, injectables can be kind of addictive, which can leave you with an unnaturally plumped or frozen face.

But according to the experts, there’s a third thing to consider: You might actually develop a resistance creating a need for more frequent injections or loss of effectiveness over time.

You’re most likely to build up resistance to botulinum injections (commonly referred to by the brand name Botox), Joshua Zeichner, M.D., director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York City, tells Allure. “Over time, you can develop antibodies to the injections because of proteins in the formulation.” There is a way around it though. “This can be overcome using higher doses, more frequent injections, or switching to another brand” (Botox, Dysport and Xeomin are all botulinum injections with slightly different formulas currently on the market).

But a filler habit might not be so sustainable either. According to Zeichner, there are two things to consider pre-plumping. First, “different fillers last variable amounts of time in the skin,” he says. “There is variation in the degree of cross linking and molecular weight and densities of the hyaluronic acid in the fillers themselves. Generally speaking, denser and more highly cross-linked products last longer in the skin.” Ask your derm how often you’ll have to come back to keep up appearances before going under the needle. Secondly, after you do get an injection, your body might burn through the fillers more quickly than the expected expiration date. “Some patients more quickly metabolize fillers so they are degraded more quickly,” Zeichner says.

Before going under the needle, chat with your dermatologist. Is this likely a one-time pick-me-up for a special event? Or are you planning on a long-term course of treatment? Together you can figure out the best plan of injectable attack.