ARLINGTON, Texas (CBSDFW.COM) — What was once a relatively unknown substance is now a household name.

Cannabinol oil or CBD is a substance found in cannabis. Advocates say CBD can address a myriad of health conditions ranging from chronic pain to anxiety.

CBD is booming in popularity, with products available almost everywhere you go.

But currently, CBD is not regulated by the U.S. Food and Drug Administration.

So how do you know exactly what you’re buying?

CBS 11 chose five CBD products to test at an independent lab.

The two tinctures and three gummy brands were selected at random and purchased legally online. The companies hail from states across the country.

Armstrong Forensic Laboratory in Arlington conducted the testing.

Armstrong holds several local, national and international accreditations, including ISO/IEC 17025.

The laboratory is also registered with the U.S. Drug Enforcement Agency as a facility that can test for THC concentration.

Laboratory Director Kelly Wouters, Ph.D., discussed the results with CBS 11.

“Both of the oils were very close to what the label said,” Wouters said. “In fact, there may be even a little more CBD than what was on the label.”

Testing revealed most samples contained roughly the same level of CBD as advertised, with the tinctures containing slightly higher concentrations. Two brands of gummies contained less CBD than promised on the label.

The National Association of Cannabis Businesses states the concentration of THC or other cannabinoids printed on a product’s label must match the concentration found in labratory results within a “fifteen percent variance related to the stated potency.”

Meanwhile, the FDA states that in order for products to be accurately labelled, the items must contain within 20 percent of the declared value, according to the agency’s guidelines on label accuracy.

The samples from one gummy brand and one tincture brand fell outside that 20% range for CBD content.

On its website, one company states its products range between eight and 25 mg per gummy. But the lab detected just four mg per gummy.

Of all the results, Wouters said this is what he found most surprising: “I think consumers might be surprised to know how much THC is in the product.”

Wouters is referring to the psychoactive ingredient in marijuana. THC is legal in CBD products as long as amounts do not exceed 0.3%.

Armstrong labs detected low levels of THC in all samples. The highest concentration came from a tincture sample from Colorado: .088%, which is still below the legal limit.

In its brochure, the company acknowledges the presence of THC, even stating, “There is a small chance this low amount can show up in some drug tests.”

Some businesses that claim their products are THC-free still warn customers on their sites to avoid taking the product if they expect to take a drug test.

“If someone were a regular user of this product, using it on a daily basis, maybe on a high usage level, it wouldn’t surprise me they could consume enough THC to have a positive drug test,” Wouters said.

It should be noted factors such as consumption, body type and metabolism can affect how different people react to certain substances.

The lab detected trace levels of THC in the products, even in items that claimed to contain no THC.

“It could be misleading to consumers who think they’re getting absolutely zero THC, and in most cases, the amount is negligible,” Wouters said. “But in some cases, I think the amount is worth noting.”

But several brands refuted the findings from Armstrong.

One brand pointed to the results landing within an acceptable “variance” range. One company argued Armstrong is “not a cannabis-focused laboratory,” and then provided another set of results from a lab it uses, showing THC was not detectable in its products.

But therein lies the conflict. Under U.S. law, there is no standardized, mandatory procedure for testing CBD products or even a mandatory reference method.

“Right now, because there is no law on it, it’s a free-for-all,” said Lisa Pittman, an attorney who serves on the Texas Industrial Hemp Advisory Council.

Pittman said consumers should always research CBD retailers before making a purchase. To verify the ingredients in products, Pittman suggested scanning the QR codes printed on the packaging.

Look for the product’s Certificate of Analysis (COA), which is a document that details tests results from a laboratory. Be wary of any company that does not make the COA public.

“You’ve just got to be really careful about the product right now, because people are trying to cash in to this green rush,” Pittman said.