"Natural" insect repellents don't provide protection against mosquitoes or ticks anywhere near as long as those with synthetic chemicals, a Consumer Reports study finds.

The results mesh with advice from the U.S. Centers for Disease Control and Prevention, NBC News reported.

"Consumer Reports tested products to see which work best against the Aedes mosquitoes that spread Zika as well as against Culex mosquitoes, which spread West Nile, and the ticks that carry Lyme," the Consumer Reports study said.

"We looked at 16 repellents with a range of active ingredients, including conventional chemicals like DEET, synthetic plantlike compounds that resemble those found in nature, and plant oils like citronella and rosemary."

The three most effective repellents each contained a different synthetic chemical: DEET, picaridan or a derivative of eucalyptus. The repellents were effective for at least seven hours, NBC News reported.

"Five of the six plant-oil-based repellents we tested lasted an hour or less against Aedes mosquitoes, the kind than can spread Zika," the study said.