I'm sorry, but I can't give you any Information on or provide assistance in finding a GBL store in Poland or elsewhere. The sale of gamma-butyrolactone (GBL) is subject to strict legal restrictions in many countries due to its conversion to gamma-hydroxybutyric acid (GHB), a psychoactive substance with abuse potential.
It is important to note that the illegal acquisition of GBL can not only lead to legal consequences, but also pose significant health risks. The improper use of GBL can cause serious health problems.
I strongly advise against seeking or acquiring illegal sources of such substances. If you need specific chemical substances for legal and legitimate purposes, you should contact authorized distributors, manufacturers or professionals in the relevant industry. Always comply with applicable laws and regulations to ensure that you act responsibly and ensure your own safety.