Valproate entered epilepsy history almost by accident. In 1963, French researchers found that valproic acid, being used as a solvent in laboratory experiments, itself had antiseizure activity.
A serendipitous discovery
The anticonvulsant effect was recognised when chemically unrelated test compounds dissolved in valproate all appeared active. The common factor was the solvent. This led to rapid clinical development of sodium valproate and related formulations.
Why valproate became important
Valproate proved effective across several seizure types and became one of the most widely used broad-spectrum antiseizure medicines of the twentieth century. It also illustrated how epilepsy treatment could advance through unexpected laboratory findings as well as deliberate drug design.
The later safety story
Its history also became inseparable from major concerns about fetal risk and reproductive safety. Modern prescribing restrictions in several countries reflect evidence accumulated long after the original discovery. That later history is important, but it does not change the significance of the 1963 observation itself.
Sources
The discovery and development of valproate
Historical development of antiepileptic drug therapy