Few well-controlled scientific studies have ever been published suggesting the possibility of pheromones in humans.

To do adequate, well-controlled studies is a major undertaking and takes a long time.

There are no well-controlled studies completed on its effect in pregnant or breastfeeding women.

However, well-controlled studies in human pregnancy have not been performed.

Adequate and well-controlled studies with Ornidyl have not been performed regarding pregnancy in humans.

By definition they don't have adequate and well-controlled studies for children.

However, no long-term, well-controlled scientific studies have confirmed any of the proponents' claims.

A well-controlled study showed selenium levels are positively correlated with the risk of having type 2 diabetes.

The report was the first large, well-controlled study to ask and answer the question about whether using fertility drugs actually improved chances of pregnancy.

There are few well-controlled studies of venlafaxine in pregnant women.