Juan Alvarado-Vargas, 22, was sentenced to 72 months behind bars followed by three years of supervised release by U.S. District Judge Marina Garcia Marmolejo.
Federal prosecutors say he was caught trying to smuggle more than 4.6 kilos of fentanyl into Texas from Mexico last October. Border Patrol agents found it hidden inside his car battery.
That's enough fentanyl to kill more than 2 million people, according to the Drug Enforcement Agency.
Alvarado-Vargas later admitted that smugglers paid him $4,500 to sneak the drug into Houston where his ultimate destination was the Galleria.
Back in April, Alvarado-Vargas pleaded guilty to conspiracy to possess with the intent to distribute, U.S. Attorney Jennifer B. Lowery said.
In handing down the prison term, Judge Marmolejo noted that fentanyl is extremely dangerous and responsible for deaths all over the United States.
Fentanyl is a synthetic painkiller drug that has morphine and opioid-like side effects, but it's 100 times more potent.
Because of its potency and low cost, drug dealers have been mixing it with other drugs -- including heroin, methamphetamine, and cocaine -- increasing the likelihood of a fatal interaction.
According to the CDC, synthetic opioids, including fentanyl, are the primary reason overdose deaths in the United States have increased dramatically.