Still, for those in favor of administering medical marijuana to the sick, regardless of age, the lack of testing is irrelevant.
"I can't guarantee it's going to do anything," said Dr. Lester Grinspoon, a retired physician and professor at Harvard Medical School. "But I can tell you it isn't going to [do] harm. [Marijuana] is remarkably non-toxic."
Grinspoon spent much of his career studying marijuana and has written several books on the benefits of the plant, including "Marijuana: The Forbidden Medicine."
He also knows firsthand about the effects of medical marijuana. In the 1970's, his young son, Danny, who was suffering with cancer, used the drug to alleviate pain and nausea caused by chemotherapy treatments. Grinspoon credits medical marijuana with making Danny's last days tolerable.
Today, Grinspoon regularly hears from moms like Mendoza and Hester-Perez, who have also found the plant helpful in relieving some of their children's symptoms for various illnesses.
In Grinspoon's mind, the most dangerous thing about marijuana just may be the stigma attached to it.
"We have been brainwashed about this substance," he said. "There will come a time when people will recognize this as the wonder drug of our times."
But to Dr. Steven Sager, a child psychiatrist and the director at Echo, a teen drug and alcohol rehab center in Malibu, Calif., and other detractors, not only is medical marijuana a bad option, but it could do more harm than good.
"I think the medical marijuana might actually be making their symptoms worse," he said. "[It] might just be kind of sedating them and not really addressing the underlying issues."
Sager also warns parents that marijuana use could cause additional problems, including anxiety and depression.
Sager urges parents and physicians to be ultra cautious when giving children any type of drug. He said parents should only use medicines that have been rigorously tested and approved by the FDA.
Mendoza is well aware of the widespread perception that marijuana is a "gateway drug," and the judgment others reflexively make when they learn of her decision to treat Ryan with medical marijuana, she said.
But, she said, if they know how severe Ryan's illness is, some would feel differently.
Shortly after Ryan's first dose of medical marijuana, the boy already was showing improvement, his mother wrote on her Web site, M-Squared, which stands for Mama to Mama. He had been refusing to go to the beach for more than a year, terrified a tsunami would hit, Mendoza wrote. But the day after he took the medicinal marijuana for the first time, the family went to the beach and, like any ordinary 12-year-old, Ryan allowed his family to bury him up to his face in sand, his mother wrote.
Ryan now takes a marijuana capsule once a day, his mother said on her site. He also is treated with liquid drops under his tongue when he is struck by severe anxiety.
While some parents like Mendoza and Hester-Perez have faith that medical marijuana will help their children, none thinks it's a magic cure.
Mendoza, perhaps, explained it best.
"[Medical marijuana] is just a piece of the puzzle. It's almost like a Band-Aid," she said. "[I give him] such a small amount. It's really just giving them medicine to treat a symptom."
She added: "It's like [the medical marijuana] just takes the edge off of his OCD. ... It's not like the OCD goes away when he has his medicine, but his ability to cope with it changes."
Mendoza wants to help other parents discover this piece of the puzzle and has become a vocal advocate for use of medical marijuana. She hopes parents struggling with how to medicate their children will reach out to her for information.
ABC News' Kimberly Brown contributed to this report.