They’re everywhere online: “free trial” offers for products to help people lose weight, erase wrinkles, boost memory, solve sexual dysfunction and whiten their teeth.

But the marketing ploys have soaked consumers for at least $1.3 billion over the past 10 years, with actual losses much higher, according to a new report from Better Business Bureau offices in Chicago and four other cities.

The offers typically involve a free trial of a product in exchange for a small shipping and handling fee.

To pay the fee, consumers must provide a credit-card number.

Often, people figure it’s such a small amount of money — typically less than $5 — that they can’t lose. They don’t realize that by responding to the free offer, they’re actually signing up for an ongoing supply of products that will be automatically billed to their credit card each month.

“Some have gone on for months … before consumers notice,” Steve Bernas, president of the Better Business Bureau of Chicago and Northern Illinois, said Wednesday.

Debbie Wagner of Oak Park, who joined Bernas and others at a news conference in Chicago on Wednesday, said she was billed $140 a month after providing her credit-card number for a shipping fee of “five or six bucks” for a supposed free trial of facial moisturizer.

The charges kept coming for months. After complaining to the Better Business Bureau, Wagner recouped a couple hundred dollars but said the rest “was a very expensive lesson.”

Wagner said the ad she responded to used a fake endorsement from panelists on the TV show “Shark Tank.”

“I thought if ‘Shark Tank’ endorsed it, it has to be legitimate,” said Wagner, who subsequently learned the endorsement was made-up.

Fake celebrity endorsements

The BBB report found numerous cases of phony free trial offers using celebrities like Oprah Winfrey, Ellen DeGeneres and Tim Allen to trick people into responding.

On “Good Morning America” on Wednesday, anchors Robin Roberts and Lara Spencer ripped free trial ads that falsely imply they endorse a product.

“They are so believable — they have quotes from us. I mean, how is this not against some kind of law or something?” Roberts said.

And it’s hard to stop the ads, Roberts said: “It’s like whack-a-mole. Because they bring down one ad … but then they go on to another one.”

The $1.3 billion figure includes only losses from cases resolved by the Federal Trade Commission. The FTC has filed at least 17 lawsuits targeting such schemes, putting several out of business, said Jason Adler, assistant director of the federal agency’s Midwest bureau.

And consumer complaints about the schemes “show no sign of slowing down,” Adler said.

Over the past three years, the Better Business Bureau system has received 36,986 complaints and “BBB Scam Tracker” reports about dubious free trial offers. Of consumers who reported a monetary loss to the nonprofit business organization, the average was $186, according to the report.

Some scam offers not only lock consumers into a recurring subscription, but they also sign up unwitting victims for a second product that carries an ongoing monthly commitment, too.

In some cases, the short period in which to cancel begins even before the free trial product has arrived, making it difficult to escape at least the first full monthly charge, which can be $100 or more.

About 72 percent of those victimized by these scams are women, and victims appear to span all income and education levels, the report said.

Bernas said victims can’t always count on their credit-card company to help. In about 50 percent of the cases, victims said their card issuer would not provide a refund.

How to protect yourself

The Better Business Bureau and the Federal Trade Commission offer consumers this advice on free trial offers: