Background: Nootropics are increasingly promoted to improve memory, attention, concentration, and intellectual performance in healthy individuals. However, their clinical evidence varies substantially, and statistically significant changes in cognitive tests do not necessarily indicate meaningful improvements in everyday functioning.

Objective: To provide clinicians with a practical and balanced overview of the efficacy, limitations, and safety of pharmacological, nutritional, and botanical interventions investigated for cognitive enhancement in healthy adults.

Methods: This narrative review examines selected randomized controlled trials, systematic reviews, and meta-analyses reporting objective cognitive outcomes in healthy adults. Evidence was interpreted according to the consistency of positive findings, cognitive domains affected, clinical applicability, and safety. Interventions were classified into three groups: more reproducible positive findings, preliminary or conflicting positive findings, and absence of demonstrated overall benefit or insufficient evidence.

Results: Caffeine produces reproducible but modest acute improvements in attention and reaction time. L-theanine, particularly combined with caffeine, may improve selected attentional outcomes. Methylphenidate and modafinil demonstrate small domain-specific effects under experimental conditions, without established benefits in everyday functioning. Creatine and Bacopa monnieri have shown favorable findings in memory and reasoning, although results remain heterogeneous. Positive findings have also been reported for Panax ginseng, Salvia, guarana, Rhodiola rosea, tyrosine, curcumin, and selected polyphenol-rich preparations, but the evidence is generally limited or population-dependent. Omega-3 supplementation has produced conflicting results, with several larger studies showing no overall benefit. Evidence does not support generalized cognitive enhancement from D-amphetamine or psychedelic microdosing.

Conclusions: Certain nootropics can improve performance in specific cognitive domains, but benefits are usually modest, context-dependent, and insufficiently validated in real-world settings. Clinicians should distinguish acute attention enhancement from sustained improvements in memory or executive function and consider reproducibility, safety, and functional relevance before interpreting claims of efficacy.