It is because the government-funded trial was a placebo-controlled, double-blind, randomized controlled trial.

FORBES

In the double-blind, randomized control trial, half the women got tenofovir gel and half got a placebo.

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The randomized, double-blind, placebo-controlled, multi-center trial enrolled 51 patients age 12 to 53 years, including 7 patients age 12 to 16 years, who were maintaining a regimen of maximally-tolerated lipid lowering medications.

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