WASHINGTON (AP) – If you’re looking for a little help shedding extra pounds after the holidays, the government is warning you to stay away from nearly 30 weight-loss products that contain unlisted and possibly dangerous ingredients.

The pills are advertised as “natural” fat busters and have intriguing names like Imelda Perfect Slim and Zhen de Shou.

But the Food and Drug Administration on Monday said the concoctions contain unlisted ingredients, including powerful appetite-suppressing drugs and a suspected carcinogen.

“These tainted weight loss products pose a great risk to public health because they contain undeclared ingredients and in some cases prescription drugs in amounts that greatly exceed their maximum recommended dosages,” said Dr. Janet Woodcock, who directs the FDA’s drug evaluation center.

Many contain sibutramine, a powerful appetite suppressant that’s a chemical cousin of amphetamines. It can cause heart attacks, strokes, heart palpitations and other problems. Some contain phenolphthalein, a chemical long used as a laxative, but which is now being withdrawn from the market because of cancer risks.

The FDA is considering criminal charges against some of the companies, because they have not responded to requests for recalls.

The products are:

Fatloss Slimming, 2 Day Diet, 3x Slimming Power, 5x Imelda Perfect Slimming, 3 Day Diet Japan Lingzhi, 24 Hours Diet, 7 Diet Day/Night Formula, 7 Day Herbal Slim, 8 Factor Diet, 999 Fitness Essence, Extrim Plus and GMP.

Also:

Imelda Perfect Slim, Lida DaiDaihua, Miaozi Slim Capsules, Perfect Slim, Perfect Slim 5x, Phyto Shape, ProSlim Plus, Royal Slimming Formula, Slim 3 in 1, Slim Express 360, Slimtech, Somotrin, Superslim, TripleSlim, Zhen de Shou, Venom Hyperdrive 3.0