There’s a black market for Botox & other things to know before getting injected

Botox Might Not Do What You Want It to
Many people confuse what Botox actually does with other age-fighting beauty injectables. “[Botox’s] only benefit is to render a muscle weaker for 3-4 months. It doesn’t fill lines, it just makes it harder to make the muscle contraction that creates the lines,” explains board-certified dermatologist Dr. Misbah Khan, owner of M. Khan Dermatology in New York City. So will it work on those wrinkles around the mouth? “No. If you have smile lines [the parentheses around the mouth], you’ll need a filler [like Restylane] to erase them.”

There’s a Black Market
Many coupon services run deals for cheap series of Botox, and they’re probably all too good to be true. Before you buy into anything, know who and what you’re dealing with. “Do not look for the better deal. Make sure you know what’s going in your face. If it’s too cheap, it may be acquired on the black market, or the Botox they’re using might be expired or about to expire,” warns Dr. Khan.

You Could Have an Allergic Reaction
You may know that Botox is derived from the same bacteria as the toxin botulism, and while you absolutely cannot catch botulism from the use of Botox, there is a small chance that you could have an allergic reaction to preservatives and ingredients used. “Some reactions that have been reported include itching, rash, welts, asthma symptoms or feeling faint,” says Dr. Dennis Gross, founder of 900 5th Dermatology and creator of Dr. Dennis Gross Skincare. If you do have a reaction, call your doctor right away.

An Unskilled Injector Might Leave You Lopsided
“If the Botox is injected wrong in any part of your face, you may have a lopsided appearance,” says Dr. Gross. “Just remember that there is an artistry involved in the technique, so be sure your physician is highly experienced and skilled at administering it.”

Overdoing It Could Lead to Drooping—or Worse

“Drooping of the eyebrows can happen even in the best of hands; it can occur if too much is injected in one place,” says Dr. Khan. And if you’re already using Botox, over-application could make it worse. “Overuse of Botox can cause the muscles to become so weak that they can’t support the flesh.” The results can look unnatural, and even worse, be painful. “If too much Botox is applied during a neck rejuvenation, it can cause the side of the face to droop, or in some cases the muscles that hold the neck up weaken to the point where you can’t swallow or hold your head up.”

Speaking Up Can Divert Disaster
You might think that you really, really want Botox no matter the small risks, but the pursuit of beauty is never worth harming your health. As with any other procedure, you should always disclose your full medical history before sitting in the chair. “Make sure to tell your doctor about all of your muscle or nerve conditions, as you may have an increased risk of serious side-effects, including difficulty swallowing and/or breathing,” cautions Dr. Gross. “Also, inform your doctor of any surgery plans, weakness of forehead muscles, recent injections, or medicines you are currently taking.” Dr. Gervaise Gerstner, L’Oréal Paris Consulting Dermatologist adds one more caution to that list: “Be sure to disclose any autoimmune neuromotor disease like myasenthia gravis.”

Results Are Not Instant
“It takes about three to seven days to show the full effect, and results will last about four months,” says Dr. Gross. And those results vary, depending on the depth of your wrinkles. “If you start Botox treatments just as fine lines are beginning to appear and continue them as you age, you can prevent select expression lines from forming at all,” advises Dr. Gross. Patients who already have pronounced lines may see benefits in a bit more time, “It takes a few days to see results, and a full two weeks to see the full effects of a Botox treatment,” explains Dr. Khan.

Botox is Not Painless
Although getting Botox is not particularly painful for most patients, since there are needles involved, you can’t expect to feel absolutely nothing when getting injected. “During the procedure, you can expect a slight pinch from the needle. There are numbing creams available in topical and aesthetic forms,” says Dr. Gross. Dr. Khan is also known to use ice to numb the area for people who have a low tolerance or phobia of needles.

Aspirin and Fish Oil Don’t Mix With Botox
“We tell our patients to stop using aspirin products up to a week before a treatment because they are blood thinners,” cautions Dr. Gross. “Discontinuing the use of aspirin the week before will help to keep bruising down. Also, we tell our patients to stop using fish oils a week beforehand because they also promote bruising for the same blood thinning reason.” Of course, always discuss changing the dosage of medicine with your primary physician beforehand.

Hair-Drying Is Off Limits Right After the Procedure
“There’s no lowering of the head for two hours post-procedure,” says Dr. Gerstner. “No yoga, no bending over, no blow drying your hair, no tight hats, no napping. In other words, heads up!”

It Might Cure More Than Wrinkles
If you have excessive underarm or palm sweating or suffer from serious migraines, talk to your doctor about using Botox to cure these ills. It’s been proven to diminish or stop excessive sweating, called hyperhidrosis, and to reduce the severity of migraines too—but don’t try tacking either treatment onto your cosmetic visit. You’ll need to book separate appointments. One quick tip: always take a quick peek at the box. “Botox meant for cosmetic purposes will say ‘Botox Cosmetic’ on the packaging,” says Dr. Khan. “Botox for medical purposes will say that on the package.”

A Happier Look Might Actually Improve Your Mood
If you’re prone to frowning, “eventually those muscles strengthen in that formation, which means it takes much effort to smile and look happy. When Botox relaxes those muscles, you look happier, which can really improve your mood and confidence,” says Dr. Gross.

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A version of this story originally appeared on iVillage.