Oxiracetam is a synthetic compound in the racetam family, often classified as a nootropic or cognitive enhancer. Its use for supporting or treating "cloudy thinking" (a non-clinical term often referred to as brain fog or cognitive impairment) is based on its potential cognitive-enhancing properties. Several animal studies and a limited number of human clinical trials have investigated oxiracetam's effects on cognition, particularly in populations with cognitive decline, such as elderly individuals or those with dementia.

Human studies have generally focused on patients with mild to moderate cognitive impairment, dementia, or Alzheimer's disease. Some trials have reported modest improvements in memory, attention, and global cognitive function compared to placebo. However, the magnitude of these effects is typically small, and the quality of evidence is limited by small sample sizes, short durations, and methodological weaknesses. There is little robust evidence supporting its use for cognitive enhancement in healthy individuals or for generalized "cloudy thinking."

Overall, while there is some scientific investigation into oxiracetam’s cognitive benefits, the evidence is not strong or conclusive. Regulatory agencies such as the FDA do not approve oxiracetam for any medical use, and large, well-controlled clinical trials are lacking. As such, oxiracetam’s use for supporting or treating "cloudy thinking" is based on preliminary scientific evidence and is not considered well-established or validated.