There's been a lot of talk about Hoodia, the weight loss supplement. But with all the weight loss products on the market how do you know if it works?

A Pennsylvania doctor said if you're taking the real-deal, there may be something to it.

The doctor in Bucks County was asked to put one brand to the test. Take a look at what he found.

"I've lost 12 pounds in 4 weeks," said Rachael Hassan.

Hassan, 28, said she took Hoodia to lose weight. She was anxious to shed a few pounds.

Hoodia comes from a cactus plant found in South Africa. Scientists discovered indigenous people who suck on the plant feel less hungry and less thirsty.

Dr. Richard Goldfarb, the medical director for the Bucks County Clinical Research Center, was asked to do research on Hoodia Dex-l-10.

He claims he has no financial interest in the company and more than that, never expected it to work.

“When I first heard about it I was in the total belief that it would not work and I was totally amazed when we did that study to find out that it did work,” Goldfarb said.

The 10 people in his study used Hoodia as directed on the label, one capsule one hour before meals. They were told not to make any other life style changes, no extra exercise or dieting.

The results?

After the 28-day study, they had lost an average of 10 pounds and about 3.3 percent of their body weight.

Most of them said that during about a week to 10 days, they had noticed instead of consuming what they would normally consume their calories were about in half.

It's important to remember Hoodia supplements are not regulated by the Food and Drug Administration. So, it's hard to know if you are getting the real thing.

Goldfarb said the product he tested, Hoodia Dex-l-10, has a permit from the Department of Agriculture in South Africa, claiming it's really Hoodia.

The most common side effect was mild stomach upset and he said he even recommended it for children.

You can find the brand the doctor tested at GNC stores and many drugstores like Rite-Aid.