Audio fileAfter more than 10 years in existence, Texas’ medical marijuana law has been expanded to include more illnesses and conditions. Only physicians registered with Texas Compassionate Use can write a prescription for medical marijuana in Texas. The Department of Justice recently issued FDA approval for medical marijuana. "And there are opportunities for people to purchase medical marijuana as they're visiting other states. It’s still illegal to transport medical marijuana across state lines, even if traveling to a state where it’s legal.