So-called “detox” teas have been popular for years, primarily among people who frequent health-food stores, or consult with alternative practitioners. These days, though, they’ve become big business, and a handful of celebrities are touting their weight-loss benefits on social media. In a way, detox teas have become the liquid version of waist trainers—the before and after results are often dramatic, and their celeb backing generates buzz, but you may be wondering: Do they really work, and are they safe? Before you plunk down your hard-earned money and start sipping, here are five things you should know.

You still have to diet and exercise for them to work


One detox tea brand, recently Instagrammed by Amber Rose, advises per their website that for “best results,” the tea should be consumed along with plenty of water, healthy, balanced meals, and three to five workouts a week. Another, which has been Instagrammed by several celebs, including Kourtney Kardashian, Christina Milian, and Hilary Duff, states online that the tea “…is recommended to be taken in conjunction with a healthy energy-controlled diet and regular exercise” and the website offers an accompanying meal plan for sale. Personally, I’d love to see a study comparing outcomes generated by a detox tea compared to a placebo, with both groups following the exact same eating plan, but I haven’t found any. That makes it difficult to know whether the weight-loss results people are getting from these teas are actually due to drinking them, or simply the result of  a cleaned-up diet and consistent workout routine, which we already know can lead to weight loss. In any case, simply sipping detox tea while continuing to skip the gym and order takeout is unlikely to help you shrink your shape. RELATED: Diet Tricks Weight-Loss Pros (Only) Tell Their Friends

You might lose water weight, not actual fat


Detox teas that combine caffeine with diuretics can trigger the loss of water weight. Just two cups of water weighs one pound on a scale, so shedding fluid can make you look and feel lighter—even if you haven’t lost an ounce of body fat. Detox teas can also trigger a laxative effect, which causes your body to eliminate waste from your GI tract, another result that can make your stomach flatter, and allow you to feel lighter, even if your lean-to-fat ratio remains exactly the same. If this quick-fix effect gives you the confidence boost and motivation you need to start eating healthier and working out—the real keys to getting healthy and lean—terrific (assuming the teas are even safe to drink—see below). Just remember: If you go back to your former less-than-stellar eating or exercise habits, or stop drinking the tea, you can gain the weight right back just as quick as you dropped it.

Some detox tea ingredients can have unwanted side effects


In addition to actual tea, detox concoctions typically include additional herbs, which may be designed to curb appetite, rev metabolism, or boost weight loss in other ways. One example is senna, a plant with a natural laxative effect. According to the Natural Medicines Comprehensive Database, the potential side effects of senna use may include abdominal pain and discomfort, cramps, bloating, gas, nausea, and diarrhea; excessive use can lead to potassium depletion and other electrolyte abnormalities, which can trigger muscle spasms and an abnormal heart rhythm. Another popular ingredient in weight loss teas is guarana, a plant that’s often added to energy drinks. Its side effects are commonly related to its caffeine content, which may include nervousness, restlessness, stomach irritation, nausea, vomiting, headache, anxiety, agitation, ringing in the ears, and fast heart and breathing rates. Bottom line: Do your homework about exactly what’s in a product before you put it in your body. Even "all-natural" substances can have potential side effects, especially if they’re overused, combined with other supplements or medications that result in negative interactions, or if taken by those with pre-existing medical conditions. RELATED: 10 Fast Weight Loss Tips (We Tried Them!)

They may interfere with sleep


Most detox teas contain caffeine, probably because this stimulant may suppress appetite, trigger your digestive system to let go of waste, and help you shed water weight. A caffeine-induced energy boost may also lead to working out a little longer or harder than usual. However, too much caffeine can also be risky (see above) and interfere with getting enough sleep—and catching too few zzzs may ultimately undo the tea’s weight-loss effects. In fact, too little shuteye has been shown to trigger excessive eating and weight gain and even slow metabolism, which can make it easier to gain weight even if you don’t eat extra calories. A good rule of thumb, regardless of where your caffeine is coming from, is to nix it at least six hours before bed. And if you’re trying to shed pounds, commit to making adequate sleep a top priority.

The research on detox teas is scant


While there are some published studies on various ingredients often found in detox teas, I haven’t seen any research on the teas themselves, particularly in the precise formulas they’re prescribed (that research isn’t required for the teas to be sold, by the way). That means that using detox teas leaves unanswered questions about if and how they work, how they should be used, how much may be too much, and possibly who shouldn’t use them. If you’re unsure, or are planning to start drinking them, talk to your doctor, nutritionist, or health care provider. Just be sure he or she doesn’t have a vested interest in the sale of the product you’re considering: If they happen to be selling or endorsing it, seek a second opinion. RELATED: Embarrassing Questions: Is It Safe to Gain and Lose Weight Like the Stars Do?   What are your thoughts on this topic? Chat with us on Twitter by mentioning @goodhealth and @CynthiaSass.

Cynthia Sass is a nutritionist and registered dietitian with master’s degrees in both nutrition science and public health. Frequently seen on national TV, she’s Health’s contributing nutrition editor, and privately counsels clients in New York, Los Angeles, and long distance. Cynthia is currently the sports nutrition consultant to the New York Rangers NHL team and the New York Yankees MLB team, and is board certified as a specialist in sports dietetics. Cynthia is a three time New York Times best selling author, and her brand new book is Slim Down Now: Shed Pounds and Inches with Real Food, Real Fast. Connect with her on FacebookTwitter and Pinterest.